Correlation between quantitative pivot shift and generalized joint laxity: a prospective multicenter study of ACL ruptures

PURPOSE

To investigate whether an increased magnitude of quantitative rotatory knee laxity is associated with a greater level of generalized joint laxity in ACL-injured and contralateral knees.

METHODS

A total of 103 patients were enrolled across four international centers to undergo anatomic ACL reconstruction. Rotatory knee laxity was evaluated preoperatively, both in the awake state and under anesthesia, using the standardized pivot shift test. Two devices were used to quantify rotatory knee laxity; an inertial sensor, measuring the joint acceleration, and an image analysis system, measuring the lateral compartment translation of the tibia. The presence of generalized joint laxity was determined using the Beighton Hypermobility Score. The correlation between the level of generalized joint laxity and the magnitude of rotatory knee laxity was calculated for both the involved knee and the non-involved knee. Further, patients were dichotomized into low (0-4) or high (5-9) Beighton Score groups. Alpha was set at < 0.05.

RESULTS

Ninety-six patients had complete datasets, 83 and 13 in the low and high Beighton Score groups respectively. In anesthetized patients, there was a significant correlation between the degree of Beighton Score and quantitative pivot shift when analyzing the non-involved knee using the image analysis system (r = 0.235, p < 0.05). When analyzing the same knee, multivariate analysis adjusted for meniscal injury, age and gender revealed an increased odds ratio for patients with increased lateral compartment translation to be part of the high Beighton Score group (OR 1.86, 95% CI 1.10-3.17, p < 0.05). No other correlation was significant. When analyzing the dichotomized subgroups, no significant correlations could be established.

CONCLUSION

The findings in this study suggest that there is a weak correlation between generalized joint laxity and the contralateral healthy knee, indicating increased rotatory knee laxity in these patients. Generalized joint laxity does not appear to correlate with rotatory knee laxity in ACL-injured knees.

LEVEL OF EVIDENCE

Prospective cohort study; level of evidence, 2.

Characteristics of disability in activity of daily living in elderly people associated with locomotive disorders

BACKGROUND

Ageing is associated with a decline of motor function and ability to perform daily activities. Locomotive disorders are one of the major disorders resulting in adverse health condition in elderly people. Concept of Locomotive syndrome (LoS) was proposed to tackle the problems and prolong healthy life expectancy of people with locomotive disorders. To develop intervention strategy for LoS it is mandatory to investigate impairments, functional disabilities which people with locomotive disorder experience and to examine relationships among these parameters. For this purpose we have developed Geriatric Locomotive Function Scale-25 (GLFS-25). Though several physical performance tests were reported for identification or monitoring the severity of LoS, there are few studies reported on characteristics of disability which people with locomotive disorders experience. The aim of this study was to report the characteristics of ADL disabilities in elderly people with locomotive disorders in terms of numbers and degree of activity limitations.

METHODS

We organized a cohort study and recruited 314 participants aged 65 years and over from five orthopedic clinics or nursing care facilities. This was a cross-sectional study to use the baseline data of such cohort. ADL disabilities were assessed using GLFS-25 scale arranging the GLFS-25 scores in ordinal levels using "R language" program. Numbers and degrees of activity limitations were determined and compared among the levels. Frequency of limitation in activities regarding social activity, housework, locomotion, mobility and self-care was compared among across the disability level.

RESULTS

The GLFS-25 score was mathematically categorized into 7 levels. The number of activity limitations and the degrees of each activity limitation were significantly greater in high GLFS-25 levels than in low levels. Difficulties in mobility appeared in less severe level, difficulties in domestic and social life appeared in moderately severe level, and difficulties in self-care appeared in advanced level.

CONCLUSIONS

High GLFS-25 score represented high degree of disability on ADLs. Concordant increase of numbers of activity limitation and severity progression in activity limitation may contribute to progression of disability. Activity limitation may occur in the following order: sports activity, walking, transferring, and self-care.

Effect of elcatonin versus nonsteroidal anti-inflammatory medications for acute back pain in patients with osteoporotic vertebral fracture: a multiclinic randomized controlled trial

The aim of this study was to compare the efficacy of elcatonin injections and oral nonsteroidal anti-inflammatory drugs (NSAIDs) for patients with osteoporosis who have acute lumbar pain after experiencing new vertebral compression fractures. Two hundred twenty-eight Japanese female patients (mean age 77.3 years) with acute lumbar pain from osteoporotic vertebral fractures were randomly divided into two groups. Patients in one group were given an NSAID (NSAIDs group) and patients in the other group were given weekly intramuscular injections of 20 units of elcatonin (elcatonin group). All patients underwent follow-up examinations up to 6 weeks from the start of the trial. Outcome measures were the level of functional impairment according to the Japan Questionnaire for Osteoporotic Pain (JQ22), the Roland-Morris Disability Questionnaire (RDQ), and a visual analog scale (VAS) of pain intensity. Statistical analyses focused on (1) the time course of pain and functional level using linear mixed effects models to analyze the longitudinal data and (2) the effectiveness of elcatonin injection with mean difference values and 95 % confidence intervals. Significant differences were seen over time between the initial values and the postintervention values (4 and 6 weeks) in JQ22, RDQ, and VAS scores (effect size d > 0.4) in each group. The mean differences between the elcatonin group and the NSAIDs group in each measure at 4 and 6 weeks were -4.8 and -8.3 for the JQ22, -1.3 and -2.6 for the RDQ, and -11.3 and -11.5 for the VAS, shifted to elcatonin. Once weekly elcatonin injection was more effective than NSAIDs for treating acute lumbar pain and improving mobility in Japanese women with osteoporotic vertebral fractures.

Bowel/bladder dysfunction and numbness in the sole of the both feet in lumbar spinal stenosis - A multicenter cross-sectional study

BACKGROUND

Numbness in the soles of both feet at rest or bowel/bladder dysfunction can occur in patients with lumbar spinal stenosis (LSS), especially in patients with cauda equina lesions. The purpose of this study was to clarify the relationship between cauda equina symptoms at rest and quality of life (QOL) in LSS patients using standardized questionnaires developed for the Japanese population.

METHODS

A survey was conducted in 564 hospitals and general practice clinics nationwide from December 1, 2011 to December 31, 2012. All patients who visited hospital or clinic because of low back pain were included. Patients were diagnosed with LSS using the LSS-Diagnostic Support Tool (LSS-DST), and the severity of the disease was measured using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) for quality of life. Presence of both sole numbness and/or bowel/bladder dysfunction were determined by medical interview. 3647 patients were diagnosed with LSS according to the results of the LSS-DST. 1294 of these patients (35.5%) had symptoms at rest. Of these patients, 359 patients with sole numbness, 135 patients with bowel/bladder dysfunction, and 52 patients with both numbness and bowel/bladder dysfunction were compared to the patients without rest symptoms (n = 2182). Comparisons between groups with or without sole numbness and bowel/bladder dysfunction were performed using statistical analysis of JOABPEQ responses in the categories of pain-related disorder, lumbar spine disorder, gait disturbance, social life disturbance, and psychological disorder.

RESULTS

All groups with sole numbness and/or bowel/bladder dysfunction had statistically lower (worse) scores in all categories of the JOABPEQ compared to the group without these symptoms at rest.

CONCLUSION

LSS patients having numbness in the soles of both feet at rest or bowel/bladder dysfunction had lower measurements of QOL and activities of daily living than those patients without symptoms at rest. These symptoms appear to be related to QOL of LSS patients.

Relationship between trunk function evaluated using the trunk righting test and physical function in patients with knee osteoarthritis

[Purpose] The present study was to validate the importance of the trunk function evaluated by trunk righting test (TRT) with motor function in patients with knee osteoarthritis (OA) and to show the clinical use of TRT. [Subjects and Methods] This study included 50 patients with knee osteoarthritis who underwent total knee arthroplasty in our hospital. Correlations between physical functional test, such as muscle strength, balance function, and performance and TRT were statistically evaluated. [Results] The independent factors for ipsilateral TRT were maximal isometric knee extensor strength test and ipsilateral step test. The operator and non-operator side TRT were significantly associated with TUG. [Conclusion] The results showed that the physical functions are correlated with the trunk function evaluated by TRT of patients with knee OA, suggesting that healthcare workers must take into consideration the trunk function, as well as lower extremity function to improve physical function.

Comparison Between Intra- and Extra-articular Tension of the Graft During Fixation in Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate the tension deprivation through the tunnels with and without preconditioning at the time of fixation, and the influences of cyclic loading and pretensioning on graft tension in anatomic single bundle anterior cruciate ligament (ACL) reconstruction using a hamstring tendon.

METHODS

Nine fresh-frozen cadaveric knees underwent anatomic ACL reconstruction using hamstring grafts. Each specimen was examined to ensure that there was no severe osteoarthritic change, ligament insufficiency, or torn menisci by manual and arthroscopic evaluation. Applied graft tension was measured at the tibial tunnel outlet using a graft tensor with a load cell. Intra-articular graft tension was evaluated by using an originally developed microforce sensor, which was sutured into the graft. Both tensions were simultaneously measured just after initial tensioning under 3 different conditions: condition 1, just after initial tensioning of 20 N at 20° of knee flexion without preconditioning; condition 2, after the same initial tensioning following 5 rounds of passive cyclic flexion-extension movement; and condition 3, after the same initial tensioning following 5 minutes of static pretensioning of 20 N.

RESULTS

The intra-articular tension was 12.7 ± 5.3 N in condition 1, 12.0 ± 4.8 N in condition 2, and 13.5 ± 4.8 N in condition 3. In these 3 conditions, intra-articular graft tension was significantly lower than the applied tension of around 20 N (no pretension: P = .009, cyclic pretension: P = .004, static pretension: P = .008), with no difference among the 3 conditions (P = .82).

CONCLUSIONS

The intra-articular graft tension was significantly lower than the applied tension from the outside of the joint, even after cyclic loading and pretensioning.

CLINICAL RELEVANCE

It is difficult to evaluate the intra-articular graft tension precisely on the basis of the extra-articular tension at time zero in ACL reconstruction.

The efficacy and safety of S-flurbiprofen plaster in the treatment of knee osteoarthritis: a phase II, randomized, double-blind, placebo-controlled, dose-finding study

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) patches are convenient for use and show much less gastrointestinal side effects than oral NSAIDs, whereas its percutaneous absorption is not sufficient for the expression of clinical efficacy at satisfactory level. S-flurbiprofen plaster (SFPP) has shown dramatic improvement in percutaneous absorption results from animal and clinical studies. In this study, the efficacy and safety of SFPP were compared with placebo in patients with knee osteoarthritis (OA) to determine its optimal dose. This was a multicenter, randomized, double-blind, parallel-group comparative study.

PATIENTS AND METHODS

Enrolled 509 knee OA patients were treated with placebo or SFPP at 10, 20, or 40 mg applied on the affected site once daily for 2 weeks. The primary endpoint for efficacy was improvement in knee pain on rising from the chair assessed by visual analog scale (VAS). The other endpoints were clinical symptoms, pain on walking, and global assessment by both investigator and patient. Safety was evaluated by observing adverse events (AEs).

RESULTS

VAS change in knee pain from baseline to trial end was dose-dependent, least squares mean was 29.5, 31.5, 32.0, and 35.6 mm in placebo and SFPP 10, 20, and 40 mg, respectively. A significant difference was observed between placebo and SFPP 40 mg (P=0.001). In contrast, the effect of SFPP at a dose ≤20 mg was not significantly different from that of placebo. The proportion of the patients who achieved 50% pain relief was 72.4% in 40 mg and 51.2% in placebo (P<0.001). In all other endpoints, SFPP 40 mg showed significant improvement compared with placebo. The incidence of AEs was not different across all four groups, and no severe AEs were observed.

CONCLUSION

Clinically relevant pain relief was observed in all groups including placebo. Especially 40 mg showed remarkable pain relief in not only primary endpoint but also all the other endpoint with significant differences over placebo. The safety profile of SFPP 40 mg was not different from that of placebo. Therefore, 40 mg was determined as the optimal tested dose.

A minimal impact of long-term S-flurbiprofen plaster application on kidney function in osteoarthritis patients

Background

The number of kidney injury due to nonsteroidal anti-inflammatory drugs (NSAIDs) is the largest among drug-induced kidney diseases. Newly developed NSAID plaster containing S-flurbiprofen (SFP) shows innovative percutaneous absorption. However, systemic exposure to SFP following the repeated application of 80 mg/day was estimated as comparable to that of oral 120 mg/day flurbiprofen and prolonged use of topical NSAIDs is common in clinical practice. Thus, we report the safety focusing on the kidney function after long-term application of SFP plaster (SFPP).

Methods

A total of 201 osteoarthritis patients (mean age; 66.3, 151 females, mean estimated glomerular filtration rate; 74.6 mL/min/1.73 mm²) were applied 40 or 80 mg SFPP for 52 weeks, and kidney function was examined by blood urea nitrogen (BUN), serum creatinine (SCr), eGFR, and urinalysis.

Results

161 (80.1%) patients completed 52-week application. In both groups of 40 and 80 mg, small but statistically significant increases were observed in BUN (mean 1.91 and 1.89 mg/dL, p < 0.05) and SCr (mean 0.019 and 0.022 mg/dL, p < 0.05). Although abnormal changes in laboratory test for renal function were observed in seven patients, all the changes were small and subclinical. Acute kidney injury was observed in two patients. Meanwhile, the investigators denied the relevance of SFPP according to the clinical course.

Conclusion

Toward the end of 52-week application, a statistically significant increase in SCr was observed in both 40 and 80 mg, but increment was small and subclinical. Attention should be paid to kidney function when applying SFPP to patients with multiple risk factors.

The Long-Term Safety of S-Flurbiprofen Plaster for Osteoarthritis Patients: An Open-Label, 52-Week Study

Background and objectives

The newly developed S-flurbiprofen plaster (SFPP) is a tape-type patch that shows innovative percutaneous absorption. This study was designed to evaluate the safety of a long-term 52-week SFPP application to osteoarthritis (OA) patients.

Methods

This was a multi-center, open-label, uncontrolled prospective study that included 201 OA patients. SFPP at 40 mg/day was applied to the site of pain in 101 patients and at 80 mg/day (2 patches) in 100 patients at a total of 301 sites for 52 weeks. The affected sites assessed included the knee (192), lumbar spine (66), cervical spine (26), and others (17). Drug safety was evaluated by medical examination, laboratory tests, and examination of vital signs. Efficacy was evaluated by the patient’s and clinician’s global assessments and clinical symptoms.

Results

Most patients (80.1 %) completed the 52-week SFPP application. The majority of drug-related adverse events (AEs) included mild dermatitis at the application sites and occurred in 46.8 % of the sites. No photosensitive dermatitis was observed. Systemic AEs occurred in 9.0 % of the patients; a serious AE (gastric ulcer hemorrhage) occurred in one patient. No clinically significant changes in the laboratory tests and vital signs were observed. The efficacy evaluation showed an improvement from 2 weeks after the SFPP application, which continued during the 52 weeks’ treatment.

Conclusions

No apparent safety concerns were observed, even during the long-term SFPP application. Therefore, SFPP could be an additional pharmacotherapy in OA treatment.

The Influence of Meniscal and Anterolateral Capsular Injury on Knee Laxity in Patients With Anterior Cruciate Ligament Injuries

BACKGROUND

The role of the anterolateral capsule (ALC) as a secondary restraint to quantitative rotatory laxity of patients with an anterior cruciate ligament (ACL) injury is currently debated.

PURPOSE/HYPOTHESIS

The purpose was to determine the influence of concomitant ALC injuries as well as injuries to other soft tissue structures on rotatory knee laxity in patients with an ACL injury. It was hypothesized that a concomitant ALC injury would be associated with increased rotatory knee laxity as measured during a quantitative pivot-shift test.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Forty-one patients with an ACL injury (average age, 23 ± 6.9 years) were enrolled. Two blinded musculoskeletal radiologists reviewed magnetic resonance imaging (MRI) scans for the presence of ACL injuries and concomitant soft tissue injuries including the ALC, medial collateral ligament, lateral collateral ligament, posterolateral corner, medial meniscus, and lateral meniscus. A standardized pivot-shift test was performed under anesthesia, and rotatory laxity was quantified according to anterior translation of the lateral tibial compartment during the pivot-shift maneuver. The Student t test was used to analyze the data. Statistical significance was set at P < .05.

RESULTS

A complete ACL rupture was confirmed in all of the patients. MRI evidence of an ALC injury was observed in 21 (51%) of the patients. Patients with MRI evidence of an ALC injury had significantly higher rotatory knee laxity (3.6 ± 1.5 mm) compared with those without an ALC injury (2.7 ± 1.5 mm; P = .04). Lateral and medial meniscus injuries were detected in 17 (41%) and 19 (46%) patients, respectively. Patients with MRI evidence of either a medial meniscus injury or lateral meniscus injury had significantly higher rotatory knee laxity compared with patients without these injuries (medial meniscus: 3.7 ± 1.4 mm vs 2.7 ± 1.6 mm, respectively; lateral meniscus: 3.7 ± 1.7 mm vs 2.7 ± 1.3 mm, respectively) (P = .03 for both).

CONCLUSION

MRI evidence of a concomitant injury to the ALC, medial meniscus, or lateral meniscus is associated with increased knee rotatory laxity in patients with an ACL injury. These structures may function as important secondary stabilizers in an ACL-injured knee. Careful assessment and proper treatment of injuries to these secondary stabilizers should be considered, especially in knees with a high level of the pivot shift.

The Influence of Knee Flexion Angle for Graft Fixation on Rotational Knee Stability During Anterior Cruciate Ligament Reconstruction: A Biomechanical Study

PURPOSE

To evaluate the effect of knee flexion angle for hamstring graft fixation, full extension (FE), or 30°, on acceleration of the knee motion during pivot-shift testing after either anatomic or nonanatomic anterior cruciate ligament (ACL) reconstruction using triaxial accelerometry.

METHODS

Two types of ACL reconstructions (anatomic and nonanatomic) using 2 different angles of knee flexion during graft fixation (FE and 30°) were performed on 12 fresh-frozen human knees making 4 groups: anatomic-FE, anatomic-30°, nonanatomic-FE, and nonanatomic-30°. Manual pivot-shift testing was performed at ACL-intact, ACL-deficient, and ACL-reconstructed conditions. Three-dimensional acceleration of knee motion was recorded using a triaxial accelerometer.

RESULTS

The anatomic-30° group showed the smallest overall magnitude of acceleration among the ACL-reconstructed groups (P = .0039). There were no significant differences among the anatomic-FE group, the nonanatomic-FE group, and the nonantomic-30° group (anatomic-FE vs nonanatomic-FE, P = .1093; anatomic-FE vs nonanatomic-30°, P = .8728; and nonanatomic-FE vs nonanatomic-30°, P = .1093). After ACL transection, acceleration was reduced by ACL reconstruction with the exception of the nonanatomic-FE group that did not show a significant difference when compared with the ACL-deficient (P = .4537).

CONCLUSIONS

The anatomic ACL reconstruction with the graft fixed at 30° of knee flexion better restored rotational knee stability compared with FE. An ACL graft fixed with the knee at FE in anatomic position did not show a significant difference compared with the nonanatomic ACL reconstructions.

CLINICAL RELEVANCE

Knee flexion angle at the time of graft fixation for ACL reconstruction can be considered to maximize the rotational knee stability.

Validation of Quantitative Measures of Rotatory Knee Laxity

BACKGROUND

Prior attempts to quantify the pivot-shift examination have been too invasive or impractical for clinical use. A noninvasive method for quantifying rotatory knee laxity is needed.

HYPOTHESIS

Greater quantitative measurements of rotatory knee laxity (both of the involved knee as well as compared with the contralateral healthy knee) are associated with an increasing clinical pivot-shift grade.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 103 patients undergoing anatomic single-bundle anterior cruciate ligament (ACL) reconstruction at 4 international centers underwent a standardized pivot-shift test preoperatively on both knees while anesthetized. Clinical grading of the pivot shift was performed according to the International Knee Documentation Committee (IKDC) knee ligament rating system. Two different quantitative technologies were used to measure rotatory knee laxity: an inertial sensor and an image analysis were independently used to measure tibial acceleration and lateral compartment translation, respectively, during the pivot-shift test. Patients were dichotomized to "high-grade" (abnormal and severely abnormal) or "low-grade" (normal and nearly normal) rotatory knee laxity groups based on the clinical pivot-shift test result of the involved side. Tibial acceleration and lateral compartment translation of the involved knee and the side-to-side difference between the involved and contralateral knees were separately compared between the high- and low-grade rotatory knee laxity groups utilizing t tests; significance was set at P < .05.

RESULTS

Forty-three patients were in the low-grade rotatory knee laxity group, and 60 patients were in the high-grade rotatory knee laxity group. Patients in the high-grade knee laxity group had significantly higher lateral compartment translation as measured with the image analysis (involved knee: 3.8 ± 2.3 mm; side-to-side difference: 2.5 ± 2.4 mm) compared with patients in the low-grade group (involved knee: 2.0 ± 1.4 mm; side-to-side difference: 1.4 ± 1.5 mm) (both P < .01). As measured with the inertial sensor, tibial acceleration for patients in the high-grade group was significantly higher (involved knee: 7.2 ± 5.3 m/s(2); side-to-side difference: 4.2 ± 5.4 m/s(2)) compared with patients in the low-grade group (involved knee: 4.2 ± 1.6 m/s(2); side-to-side difference: 1.2 ± 1.2 m/s(2)) (both P < .01).

CONCLUSION

The inertial sensor and image analysis techniques were able to detect differences between low- and high-grade pivot-shift test results. A quantitative assessment of the pivot-shift test could augment the diagnosis of an ACL injury and improve the ability to detect changes in rotatory knee laxity over time.

Biomechanical Function of Anterior Cruciate Ligament Remnants: Quantitative Measurement With a 3-Dimensional Electromagnetic Measurement System

PURPOSE

To evaluate quantitatively the biomechanical function of anterior cruciate ligament (ACL) remnants in patients with ACL injuries. Anterior tibial translation (ATT) with KT-1000 and during the Lachman test with an electromagnetic measurement system (EMS) and tibial acceleration during the pivot shift test with EMS were measured.

METHODS

A total of 121 unilateral ACL injuries were examined. ACL remnants were morphologically classified as being attached to the posterior cruciate ligament (PCL group), to the roof of the intercondylar notch (RIN group), to the lateral wall of the intercondylar notch (LWIN group), or as having no substantial remnants (NONE group). Partial ACL tears were excluded. ATT was measured using KT-1000. ATT during the Lachman test and tibial acceleration during the pivot shift test were measured using EMS.

RESULTS

ACL remnant patterns were as follows: PCL group, 27 knees; RIN group, 34 knees; LWIN group, 27 knees; and NONE group, 33 knees. The ATT side-to-side difference in LWIN group (3.4 ± 0.7 mm) by KT-1000 was significantly smaller than the RIN (5.7 ± 1.0 mm) and NONE groups (5.9 ± 1.0 mm) (P < .05). The ATT side-to-side difference during the Lachman test was significantly smaller in the LWIN group (5.3 ± 1.2 mm) than the PCL (8.6 ± 1.4 mm), RIN (8.5 ± 1.2 mm), and NONE groups (7.6 ± 1.0 mm) (P < .05). Tibial accelerations were 2.0 ± 0.4, 1.7 ± 0.2, 1.9 ± 0.2, and 1.8 ± 0.3 m/s(2) in the PCL, RIN, LWIN, and NONE groups, respectively. There were no significant differences among groups.

CONCLUSIONS

ACL remnants attached to the lateral wall of the intercondylar notch partially contributed to anterior-posterior stability but did not contribute to dynamic knee stability. These findings suggest that ACL remnants attached to nonanatomic insertion sites do not contribute significantly to knee stabilization.

LEVEL OF EVIDENCE

Level III, diagnostic study of nonconsecutive patients.

Objective measures on knee instability: dynamic tests: a review of devices for assessment of dynamic knee laxity through utilization of the pivot shift test

Current reconstructive methods used after anterior cruciate ligament (ACL) injury do not entirely restore native knee kinematics. Evaluation of dynamic knee laxity is important to accurately diagnose ACL deficiency, to evaluate reconstructive techniques, and to construct treatment algorithms for patients with ACL injury. The purpose of this study is to present recent progress in evaluation of dynamic knee laxity through utilization of the pivot shift test. A thorough electronic search was performed and relevant studies were assessed. Certain dynamic knee laxity measurement methods have been present for over 10 years (Navigation system, Electromagnetic sensor system) while other methods (Inertial sensor, Image analysis system) have been introduced recently. Methods to evaluate dynamic knee laxity through the pivot shift test are already potent. However, further refinement is warranted. In addition, to correctly quantify the pivot shift test, the involved forces need to be controlled through either standardization or mechanization of the pivot shift test.

Arthroscopic image distortion-part I: the effect of lens and viewing angles in a 2-dimensional in vitro model

PURPOSE

Arthroscopic images are subject to distortion, which may increase when using arthroscope lenses with greater reflecting angles and/or viewing structures at oblique angles. The purpose of this study was to determine the magnitude of image distortion experienced when using arthroscopes with different lens angles and when the line-of-sight (i.e., viewing angle) is not directly perpendicular to the target.

METHODS

A dot calibration target was captured through 0°, 30°, and 70° arthroscopes from straight (i.e., directly perpendicular) and 30° oblique viewing angles. Distortions in horizontal and vertical distances in deep (located at 87.5 % length of arthroscopic image diameter) or shallow (12.5 % diameter length) regions were calculated, from which a deformity ratio (horizontal/vertical distance) was determined.

RESULTS

From the straight viewing angle (0°), both horizontal and vertical distances were artificially reduced (i.e., <100 % magnification) in the shallow and deep regions. The deformity ratio was ~100 % in the central region, declining to ~80 % peripherally. From the oblique viewing angle (30°), magnification was below 100 % in the deep area but exceeded 100 % in the shallow area, with increasing distortion associated with increasing lens angle (0° < 30° < 70°). For all lens angles, the deformity ratio was ~50 % in the deep area but neared 100 % in the shallow region.

CONCLUSIONS

Arthroscopic image distortion in peripheral regions should be considered when using angled-lens arthroscopes, especially when the viewing angle is not straight. As viewing the femoral ACL footprint through the anterolateral portal involves using an oblique viewing angle, visualization through the anteromedial portal is recommended.

Efficacy of S-flurbiprofen plaster in knee osteoarthritis treatment: Results from a phase III, randomized, active-controlled, adequate, and well-controlled trial

OBJECTIVES

S-flurbiprofen plaster (SFPP) is a novel non-steroidal anti-inflammatory drug (NSAID) patch, intended for topical treatment for musculoskeletal diseases. This trial was conducted to examine the effectiveness of SFPP using active comparator, flurbiprofen (FP) patch, on knee osteoarthritis (OA) symptoms.

METHODS

This was a phase III, multi-center, randomized, adequate, and well-controlled trial, both investigators and patients were blinded to the assigned treatment. Enrolled 633 knee OA patients were treated with either SFPP or FP patch for two weeks. The primary endpoint was improvement in knee pain on rising from the chair as assessed by visual analogue scale (rVAS). Safety was evaluated through adverse events (AEs).

RESULTS

The change in rVAS was 40.9 mm in SFPP group and 30.6 mm in FP patch group (p < 0.001). The incidence of drug-related AEs at the application site was 9.5% (32 AEs, 29 mild and 3 moderate) in SFPP and 1.6% in FP patch (p < 0.001). Withdrawals due to AE were five in SFPP and one in FP patch.

CONCLUSIONS

The superiority of SFPP in efficacy was demonstrated. Most of AEs were mild and few AEs led to treatment discontinuation. Therefore, SFPP provides an additional option for knee OA therapy.

Polyacrylamide backbones for polyvalent bioconjugates using “post-click” chemistry

This paper reports the synthesis and application of acrylamide-type neoglycoconjugates interacting with practical targets.

Plasma pharmacokinetics and synovial concentrations of S-flurbiprofen plaster in humans

PURPOSE

The purpose of this study is to investigate the pharmacokinetics and deep tissue penetration capability of the newly developed S-flurbiprofen plaster (SFPP) in humans.

METHODS

Study 1: SFPP tape-type patch (2-60 mg) was applied to the lower back for 24 h in healthy adult volunteers. S-flurbiprofen (SFP) plasma concentration was measured over time to examine SFP pharmacokinetics. Study 2: SFPP (20 mg) was applied for 12 h to the affected knee of osteoarthritis (OA) patients who were scheduled for total knee arthroplasty. Deep tissues (synovial tissue and synovial fluid) were collected during surgery to compare SFP concentrations after application of SFPP or a commercially available flurbiprofen (FP) gel-type patch.

RESULTS

Study 1: The plasma concentration of SFP was sustained during 24-h topical application of the SFPP, showing a high percutaneous absorption ratio of 51.4-72.2 %. Cmax and AUC0-∞ were dose-proportional. Study 2: After application of the SFPP for 12 h, SFP concentrations in the synovial tissue and synovial fluid were 14.8-fold (p = 0.002) and 32.7-fold (p < 0.001) higher, respectively, than those achieved by the FP patch.

CONCLUSIONS

Sustained plasma concentration of SFP and high percutaneous absorption ratio was observed after 24-h topical application of the SFPP. Compared to the FP patch, the SFPP showed superior percutaneous absorption and greater tissue penetration of SFP into the synovial tissue. Greater tissue penetration of the SFPP seemed to be primarily due to its formulation. Thus, SFPP is expected to show higher efficacy for the treatment of knee OA.

A Comparison of Ligament Tensions Between Intra- and Extra-Articular Measurement in Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction is one of the treatments of ACL injuries. In the surgery, the reconstructed ligament should be properly tensioned to provide a normal ligament behavior. However, the ligament tension has been measured with an extra-articular technique in past studies, while the intra-articular ligament tension is still unknown. The purpose of this study is to compare the ligament tensions between intra- and extra-articular measurements in the ACL reconstruction. Intra-articular measurement employs a micro-force sensor designed with a width and thickness same as those of the reconstructed ligament. This study performed two experiments (i.e., sensor accuracy and cadaveric study). In the sensor accuracy experiment, the accuracy of the sensor was about 3% until an applied force of 100 N. In the cadaveric study, the results of the intra- and extra-articular measurement tensions were 13.6±3.9 N and 18.7±1.3 N (n= 6), respectively. The significant difference in student t-test (p-value was 0.026) between the intra- and extra- articular measurements was observed. The bending angle and friction between the graft and bone tunnel, and the shape of the intra-articular edge of tibial bone tunnel affected the intra-articular measurement in ACL reconstruction.

A novel objective evaluation method for trunk function

[Purpose] To investigate whether an objective evaluation method for trunk function, namely the “trunk righting test”, is reproducible and reliable by testing on different observers (from experienced to beginners) and by confirming the test-retest reliability. [Subjects] Five healthy subjects were evaluated in this correlation study. [Methods] A handheld dynamometer was used in the assessments. The motor task was a trunk righting motion by moving the part with the sensor pad 10 cm outward from the original position. During measurement, the posture was held at maximum effort for 5 s. Measurement was repeated three times. Interexaminer reproducibility was examined in two physical therapists with 1 year experience and one physical therapist with 7 years of experience. The measured values were evaluated for reliability by using intraclass correlation coefficients (ICC 1.1) and interclass correlation coefficients (ICC 2.1). [Results] The test-retest reliability ICC 1.1 and ICC 2.1 were all high. The ICC 1.1 was >0.90. The ICC 2.1 was 0.93. [Conclusion] We developed the trunk righting test as a novel objective evaluation method for trunk function. As the study included inexperienced therapists, the results suggest that the trunk righting test could be used in the clinic, independent of the experience of the therapists.

Fully Automated Determination of Femoral Coordinate System in CT Image Based on Epicondyles

We propose a fully automated determination of the femoral coordinates in computerized tomography (CT) imaging based on epicondyles. The challenge point of this paper is that we take up how to calculate the femoral coordinate system (FCS), which is difficult to determine automatically. Our proposed method automatically determines the FCS based on anatomical reference points. We evaluated 10 subjects (six men and four women 28.9 ± 9.3 years old, three left-handed and seven right-handed) who had no history of joint injury. We examined the proposed method by comparing the expert and algorithm. The medial epicondyle was 1.41 ± 0.75 mmp= 0.42 > 0.05, student’sttest) in positioning accuracy. The lateral epicondyle was 1.36 ± 0.70 mmp= 0.42) in positioning accuracy. The origin was 0.87 ± 0.40 mmp= 0.71). in positioning accuracy. The lateral axis angle accuracy was 0.53 ± 0.84°p= 0.44). In short, the proposed method constructed patient-specific coordinate systems more accurately than expert manual.

Hydrocarbons preserved in a ~2.7 Ga outcrop sample from the Fortescue Group, Pilbara Craton, Western Australia

The hydrocarbons preserved in an Archean rock were extracted, and their composition and distribution in consecutive slices from the outside to the inside of the rock were examined. The 2.7 Ga rock was collected from the Fortescue Group in the Pilbara region, Western Australia. The bitumen I (solvent-extracted rock) and bitumen II (solvent-extracted hydrochloric acid-treated rock) fractions have different hydrocarbon compositions. Bitumen I contains only trace amounts of aliphatic hydrocarbons and virtually no aromatic hydrocarbons. In contrast, bitumen II contains abundant aliphatic and aromatic hydrocarbons. The difference seems to reflect the weathering history and preservational environment of the investigated rock. Aliphatic hydrocarbons in bitumen I are considered to be mainly from later hydrocarbon inputs, after initial deposition and burial, and are therefore not indigenous. The lack of aromatic hydrocarbons in bitumen I suggests a severe weathering environment since uplift and exposure of the rock at the Earth's surface in the Cenozoic. On the other hand, the high abundance of aromatic hydrocarbons in bitumen II suggests that bitumen II hydrocarbons have been physically isolated from removal by their encapsulation within carbonate minerals. The richness of aromatic hydrocarbons and the relative scarcity of aliphatic hydrocarbons may reflect the original compositions of organic materials biosynthesised in ancient organisms in the Archean era, or the high thermal maturity of the rock. Cyanobacterial biomarkers were observed in the surficial slices of the rock, which may indicate that endolithic cyanobacteria inhabited the surface outcrop. The distribution of aliphatic and aromatic hydrocarbons implies a high thermal maturity, which is consistent with the lack of any specific biomarkers, such as hopanes and steranes, and the prehnite-pumpellyite facies metamorphic grade.

Effect of tear location on propagation of isolated supraspinatus tendon tears during increasing levels of cyclic loading

BACKGROUND

The morphology of the supraspinatus tendon may affect tear propagation. It was hypothesized that tears located in the anterior third of the supraspinatus tendon would propagate more readily and would require lower loads to reach critical amounts of tear propagation than those located in the middle third of the supraspinatus tendon.

METHODS

Twenty-three fresh-frozen human cadaveric shoulders were tested under increasing levels of cyclic loading. Tears were created in the anterior third (Group A, n=10) or the middle third (Group M, n=13) of the supraspinatus tendon. The maximum load at which a critical tear retraction was reached and the tear area for the final loading set were compared between groups. A correlation analysis was also performed for age compared with maximum load.

RESULTS

No significant differences were found between the anterior-third tear group (Group A) and the middle-third tear group (Group M) in maximum load (p=0.09) or tear area (p=0.6). However, Group A first reached a 100% increase in tear size at a significantly lower load than Group M (p=0.03). Strong negative correlations were detected between age and maximum load in Group A (τ=-0.82) and Group M (r=-0.63).

CONCLUSIONS

Other factors being equal, tears in the anterior supraspinatus tendon may propagate more readily than tears in the tendon's middle part. Age may be a factor for tear propagation.

CLINICAL RELEVANCE

Older patients and patients with tears in the anterior supraspinatus should be followed especially carefully.

[Locomo 25--a screening tool for risk of locomotive syndrome]

Locomo 25 was developed as a screening tool of locomotive syndrome by Japanese orthopedic surgeon group in 2008. It contains 25 questions in terms of musculoskeletal disorder such as walking disability, difficulty in daily living, or suffering pain on body. Its reliability and validity were already confirmed through multi-center study including 731 Japanese elderly people (over 65 y.o. average 77 y.o.). The cutoff score for identifying locomotive syndrome was set at 16, and list-upped person is considered as under high-risk condition who may soon require care services without some medical interventions. We can use Locomo 25 not only as a screening tool of locomotive syndrome but also as a measuring scale for evaluating effects of interventions in individuals.

A Three-Dimensional Evaluation of EndoButton Displacement Direction After Anterior Cruciate Ligament Reconstruction in CT Image Using Tunnel Axis

The goal of this study was to propose a threedimensional evaluation of the EndoButton displacement direction after anterior cruciate ligament reconstruction in the multidetector-row computed tomography (MDCT) image by using the tunnel axis. The proposed method was applied experimentally to six subjects. The result of the simulated experiment revealed that the proposed method could analyze EndoButton displacement direction satisfactorily because the error was less than that of the MDCT image resolution. The clinical experiment results revealed displacement relative to the tunnel between time-zero and the followup point. We conclude that the proposed method can quantitatively evaluate the EndoButton displacement direction from the raw MDCT image after anterior cruciate ligament reconstruction; further, our findings suggest that the EndoButton was displaced relative to the tunnel between time-zero and the follow-up point.

Three-dimensional analysis of bone tunnel changes after anatomic double-bundle anterior cruciate ligament reconstruction using multidetector-row computed tomography

BACKGROUND

The femoral and tibial bone tunnel enlargement after anatomic double-bundle anterior cruciate ligament reconstruction (ACL-R) has not been fully documented.

PURPOSE

To evaluate the region-specific bone tunnel volume changes and those transpositions using 3-dimensional multidetector-row computed tomography (MDCT) after anatomic double-bundle ACL-R.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Eleven patients who underwent unilateral double-bundle ACL-R with hamstring tendon autografts were included in this study. MDCT scanning of their knees was performed at 3 weeks and 1 year after surgery. The bone tunnel regions were extracted from the MDCT images, and the longitudinal axis of each bone tunnel was divided into 3 equal sections. The centroids of the outside and the articular thirds were then extracted from the bone tunnel position. Changes in the bone tunnel volume and the transposition of the articular third were calculated and compared.

RESULTS

At 1 year postoperatively, as compared with the 3-week postoperative value (set at 100%), the femoral bone tunnel volume of the anteromedial bundle (AMB) and posterolateral bundle (PLB) changed to 77.4% ± 15.3% and 102.3% ± 19.2% in the outside third and 122.3% ± 31.8% and 112.5% ± 34.4% in the articular third, respectively. The tibial bone tunnel volume of the AMB and the PLB changed to 108.6% ± 28.7% and 105.4% ± 22.6% in the tibial articular third and 54.9% ± 25.8% and 52.5% ± 26.9% in the outside third, respectively. The femoral outside third of the AMB and the tibial outside third of both the AMB and PLB were significantly reduced in bone tunnel volume. The centroid of the femoral articular third of the AMB moved 13°, 1.1 ± 0.6 mm posterodistally, and that of the PLB moved 35°, 0.8 ± 0.4 mm anterodistally. Furthermore, the centroid of the tibial articular third of the AMB moved 14°, 2.0 ± 1.6 mm posterolaterally, and that of the PLB moved 72°, 1.0 ± 1.3 mm posterolaterally.

CONCLUSION

Compared with 3 weeks postoperatively, the articular side outlets of the femoral and tibial bone tunnels at 1 year postoperatively had enlarged slightly but statistically maintained their volume, and they had moved a little in the direction that the grafts were pulled.

Individualized ACL reconstruction

The pivot shift test is the only physical examination test capable of predicting knee function and osteoarthritis development after an ACL injury. However, because interpretation and performance of the pivot shift are subjective in nature, the validity of the pivot shift is criticized for not providing objective information for a complete surgical planning for the treatment of rotatory knee laxity. The aim of ACL reconstruction was eliminating the pivot shift sign. Many structures and anatomical characteristics can influence the grading of the pivot shift test and are involved in the genesis and magnitude of rotatory instability after an ACL injury. The objective quantification of the pivot shift may be able to categorize knee laxity and provide adequate information on which structures are affected besides the ACL. A new algorithm for rotational instability treatment is presented, accounting for patients' unique anatomical characteristics and objective measurement of the pivot shift sign allowing for an individualized surgical treatment.

LEVEL OF EVIDENCE

V.

Determination of the optimal cutoff time to use when screening elderly people for locomotive syndrome using the one-leg standing test (with eyes open)

OBJECTIVE

To establish the cutoff time for the one-leg standing (OLS) test (with eyes open) to use when screening elderly people for locomotive syndrome.

METHODS

Patients visiting orthopedic clinics and healthy volunteers, all ≥65 years old, were recruited. Participants were asked to complete the 25-question Geriatric Locomotive Function Scale (GLFS-25) and then underwent the OLS test. Using the previously determined GLFS-25 cutoff value, participants were divided into two groups: the locomotive and the non-locomotive syndrome groups (GLFS-25 scores of ≥16 and <16, respectively). Conventional receiver operating characteristic curve (ROC) analysis was used to calculate the optimal cutoff time for the OLS.

RESULTS

Data from 880 individuals (261 men, 619 women; mean age (SD), 77 (6) years; range 65-96 years) were analyzed; 497 were in the locomotive syndrome group and 383 were in the non-locomotive syndrome group. A significant difference was seen between each group mean for individual average (IA) OLS times (IA-OLS: the average of the OLS times obtained for both legs of an individual). According to ROC analysis without age adjustment, when the IA-OLS time was ~9 s, the sum of the sensitivity and specificity of the test was highest. However, because of a statistically significant difference in IA-OLS time among the three age groups (aged ≤70, aged >70 and ≤75, and aged >75), we determined the optimal cutoff value for IA-OLS time for each of the three age groups using ROC analysis. According to additional ROC analysis, the optimal cutoff for IA-OLS time was 19 s for individuals aged ≤70, 10 s for individuals aged >70 and ≤75, and 6 s for individuals aged >75 when screening elderly persons for locomotive syndrome.

CONCLUSIONS

We propose using a GLFS-25 score of 16 and/or a cutoff for the IA-OLS time of 19 s for individuals aged ≤70, 10 s for individuals aged >70 and ≤75, and 6 s for individuals aged >75 when screening elderly persons to determine who should receive medical intervention or undergoing training programs.

A comparison of dynamic rotational knee instability between anatomic single-bundle and over-the-top anterior cruciate ligament reconstruction using triaxial accelerometry

PURPOSE

Recently, single-bundle (SB) anterior cruciate ligament (ACL) reconstruction has been advanced by the anatomic concept, but the biomechanical outcome of the anatomic method has not been fully investigated, especially for rotational instability. Anatomic SB and the single over-the-top procedures are the treatment of choice for primary cases and revision or skeletally immature cases, respectively. The purpose of this study was to investigate the dynamic rotational instability of anatomic SB and over-the-top reconstruction during a pivot shift test using triaxial accelerometry.

METHODS

Eight fresh frozen human cadaveric knees were used in this study. Rotational instability measurement was conducted during a pivot shift test by the use of a triaxial accelerometer attached to the tibia. The tests were performed in the ACL-intact, ACL-deficient and ACL-reconstructed knees with two different procedures (anatomic SB and over-the-top). The acceleration in three directions and the magnitude of acceleration were measured to evaluate rotational instability and compare between four different knee states.

RESULTS

The overall magnitude of acceleration was significantly different (P < 0.01) between the ACL-intact knees and the ACL-deficient knees. Both anatomic SB and over-the-top ACL reconstruction significantly reduced the overall magnitude of acceleration compared to the ACL-deficient knees, but still had larger accelerations compared to the ACL-intact knees. There was no significant difference for the overall magnitude of acceleration between anatomic SB and over-the-top reconstruction procedure.

CONCLUSION

Over-the-top reconstruction provides comparable result to anatomic SB reconstruction in terms of controlling the dynamic rotational stability. Over-the-top reconstruction might be one of the options for revision cases and in skeletally immature patients.

MicroRNAs as tumour suppressors in canine and human melanoma cells and as a prognostic factor in canine melanomas

Malignant melanoma (MM) is one of the most aggressive cancers in dogs and in humans. However, the molecular mechanisms of its development and progression remain unclear. Presently, we examined the expression profile of microRNAs (miRs) in canine oral MM tissues and paired normal oral mucosa tissues by using the microRNA-microarray assay and quantitative RT-PCR. Importantly, a decreased expression of miR-203 was significantly associated with a shorter survival time. Also, miR-203 and -205 were markedly down-regulated in canine and human MM cell lines tested. Furthermore, the ectopic expression of miR-205 had a significant inhibitory effect on the cell growth of canine and human melanoma cells tested by targeting erbb3. Our data suggest that miR-203 is a new prognostic factor in canine oral MMs and that miR-205 functions as a tumour suppressor by targeting erbb3 in both canine and human MM cells.

An Automatic Three-Dimensional Evaluation of Screw Placement After Anterior Cruciate Ligament Reconstruction Using MDCT Images

A metallic interference screw, which is a fixation device used in anterior cruciate ligament (ACL) reconstruction, is important for fixing the grafts to the tibia. Loosening of fixation sometimes happens because the screw is displaced time passes, which results in instability of the knee. It is therefore important to analyze screw displacement highly accurately. The purpose of this study is to propose an evaluation of screw displacement in MDCT imaging of the knee after ACL reconstruction. Clinical experiments used 22 MDCT images that are not displaced in the clinical sense. Results of simulation experiments show that error was 0.14 mm, which was less thanMDCT image resolution. This study concluded that the proposed method useful in evaluating two MDCT images at different time points.

Comparative analysis of mRNA expression of surface antigens between histiocytic and nonhistiocytic sarcoma in dogs

Background

Definitive diagnosis of histiocytic sarcoma (HS) in dogs is relatively difficult by conventional histopathological examination because objective features of HS are not well defined.

Hypothesis

Quantitative analysis of mRNA expression of selected cellular surface antigens (SAs) specific to HS in dogs can facilitate objective and rapid diagnosis.

Animals

Dogs with HS (n = 30) and dogs without HS (n = 36), including those with other forms of lymphoma (n = 4), inflammatory diseases (n = 6), and other malignant neoplasias (n = 26).

Methods

Retrospective clinical observational study. Specimens were collected by excisional biopsy, needle core biopsy, or fine needle aspiration. To determine HS detection efficacy, mRNA expression levels of selected SAs specific to HS in dogs, including MHC class IIα, CD11b, CD11c, and CD86, were quantitatively analyzed using real‐time quantitative polymerase chain reaction.

Results

Each SA mRNA expression level was significantly higher in HS dogs than in non‐HS dogs (P = .0082). Cutoff values for discriminating between HS and non‐HS dogs based on these expression levels were calculated on the basis of receiver‐operating characteristic analysis. Accuracy of the cutoff values, including MHC class IIα, CD11b, CD11c, and CD86, was 87.9, 86.4, 86.4, and 84.8%, respectively.

Conclusions and Clinical Importance

Our results suggest that quantitative analysis of mRNA expression of the selected SAs could be an adjunctive diagnostic technique with high diagnostic accuracy for HS in dogs. Substantial investigation is required for exclusion of diseases with similar cell types of origin to lymphoma.

Can joint contact dynamics be restored by anterior cruciate ligament reconstruction?

BACKGROUND

Rotational kinematics has become an important consideration after ACL reconstruction because of its possible influence on knee degeneration. However, it remains unknown whether ACL reconstruction can restore both rotational kinematics and normal joint contact patterns, especially during functional activities.

QUESTIONS/PURPOSES

We asked whether knee kinematics (tibial anterior translation and axial rotation) and joint contact mechanics (tibiofemoral sliding distance) would be restored by double-bundle (DB) or single-bundle (SB) reconstruction.

METHODS

We retrospectively studied 17 patients who underwent ACL reconstruction by the SB (n = 7) or DB (n = 10) procedure. We used dynamic stereo x-ray to capture biplane radiographic images of the knee during downhill treadmill running. Tibial anterior translation, axial rotation, and joint sliding distance in the medial and lateral compartments were compared between reconstructed and contralateral knees in both SB and DB groups.

RESULTS

We observed reduced anterior tibial translation and increased knee rotation in the reconstructed knees compared to the contralateral knees in both SB and DB groups. The mean joint sliding distance on the medial compartment was larger in the reconstructed knees than in the contralateral knees for both the SB group (9.5 ± 3.9 mm versus 7.5 ± 4.3 mm) and the DB group (11.1 ± 1.3 mm versus 7.9 ± 3.8 mm).

CONCLUSIONS

Neither ACL reconstruction procedure restored normal knee kinematics or medial joint sliding.

CLINICAL RELEVANCE

Further study is necessary to understand the clinical significance of abnormal joint contact, identify the responsible mechanisms, and optimize reconstruction procedures for restoring normal joint mechanics after ACL injury.

Immune therapeutic potential of stem cells from human supernumerary teeth

Discoveries of immunomodulatory functions in mesenchymal stem cells (MSCs) have suggested that they might have therapeutic utility in treating immune diseases. Recently, a novel MSC population was identified from dental pulp of human supernumerary teeth, and its multipotency characterized. Herein, we first examined the in vitro and in vivo immunomodulatory functions of human supernumerary tooth-derived stem cells (SNTSCs). SNTSCs suppressed not only the viability of T-cells, but also the differentiation of interleukin 17 (IL-17)-secreting helper T (Th17)-cells in in vitro co-culture experiments. In addition, systemic SNTSC transplantation ameliorated the shortened lifespan and elevated serum autoantibodies and nephritis-like renal dysfunction in systemic lupus erythematosus (SLE) model MRL/lpr mice. SNTSC transplantation also suppressed in vivo increased levels of peripheral Th17 cells and IL-17, as well as ex vivo differentiation of Th17 cells in MRL/lpr mice. Adoptive transfer experiments demonstrated that SNTSC-transplanted MRL/lpr mouse-derived T-cell-adopted immunocompromised mice showed a longer lifespan in comparison with non-transplanted MRL/lpr mouse-derived T-cell-adopted immunocompromised mice, indicating that SNTSC transplantation suppresses the hyper-immune condition of MRL/lpr mice through suppressing T-cells. Analysis of these data suggests that SNTSCs are a promising MSC source for cell-based therapy for immune diseases such as SLE.

Differences in Knee Kinematics Between Awake and Anesthetized Patients During the Lachman and Pivot-Shift Tests for Anterior Cruciate Ligament Deficiency

Background:

The Lachman and pivot-shift tests have been widely used for detecting anterior cruciate ligament (ACL) deficiency. However, it still remains unclear whether these manual tests can be quantified accurately while patients are awake.

Purpose:

To assess the differences in knee kinematics of awake and anesthetized patients.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 50 patients with unilateral ACL rupture were examined. Anteroposterior tibial translation was assessed using a KT-1000 arthrometer at maximal manual power. Anterior tibial translations during the manual Lachman test and the acceleration of tibial posterior translation (APT) during the pivot-shift test were also measured using an electromagnetic measurement system (EMS). All 3 measurements were performed on the day previous to surgery while the patients were awake and on the operative day before the surgery while the patients were under general anesthesia.

Results:

The mean side-to-side difference in anteroposterior tibial translation was 5.6 ± 2.6 mm in the awake state and 5.9 ± 3.5 mm under anesthesia, indicating a nonsignificant difference. According to the EMS, the mean side-to-side difference in anteroposterior tibial translation during the Lachman test was 4.6 ± 3.6 mm in the awake state and 6.9 ± 4.3 mm under anesthesia, indicating a significant difference (P < .01). The mean APT during the pivot-shift test was −0.8 ± 0.3 m/s² in intact knees and −1.1 ± 0.4 m/s² in ACL-deficient knees when the patients were awake and was −0.7 ± 0.2 m/s² and −1.7 ± 1.0 m/s², respectively, when the patients were under anesthesia. In ACL-deficient knees, the APT pivot-shift test result was significantly higher when the patients were under anesthesia than when they were awake (P < .01).

Conclusion:

In ACL-deficient knees, the knee kinematics during the Lachman and pivot-shift tests is significantly affected by patient consciousness, and caution is needed in quantifying anterior knee laxity during these tests when the patients are awake.

The effect of tunnel placement on rotational stability after ACL reconstruction: evaluation with use of triaxial accelerometry in a porcine model

PURPOSE

Conventional transtibial technique fails to restore the rotational knee stability in spite of successful anterior laxity, while anatomic anterior cruciate ligament reconstruction using the anteromedial portal technique has been developed expecting better rotational kinematics because of closer reproduction of the native anterior cruciate ligament anatomy. However, the rotational instability after those two procedures has not been fully examined especially in terms of dynamic component of the rotational stability. The purpose was to assess the effect of anatomic versus non-anatomic tunnel placement on rotational knee stability after anterior cruciate ligament reconstruction using triaxial accelerometry.

METHODS

Sixteen porcine knees underwent a manual pivot-shift test at four different conditions: (1) anterior cruciate ligament intact, (2) anterior cruciate ligament deficient, (3) non-anatomic transtibial reconstruction, and (4) anatomic anteromedial portal reconstruction. The three-dimensional acceleration of knee motion during the pivot-shift test was recorded using a triaxial accelerometer.

RESULTS

Both anterior cruciate ligament reconstructions decreased significantly the acceleration of the pivot-shift test from the increased level in the anterior cruciate ligament-deficient condition. However, the transtibial technique fails to reach the intact level of acceleration, while the anteromedial portal technique reduced the acceleration to even less than the intact level.

CONCLUSION

The transtibial anterior cruciate ligament reconstruction could not restore the dynamic rotational stability of the intact knee, whereas the anteromedial portal technique restored the dynamic rotational stability closer to the intact level.

LEVEL OF EVIDENCE

III.

Therapeutic advantage in selective ligament augmentation for partial tears of the anterior cruciate ligament: results in an animal model

BACKGROUND

As a result of recent studies describing the double-bundle anterior cruciate ligament (ACL), selected ACL augmentation procedures, either anteromedial (AM) or posterolateral (PL), have been introduced as the treatment of choice for partial ACL ruptures. The preserved mechanoreceptor and vascularity of the remnant ACL are considered to provide additional biological benefits. Although enhanced knee joint proprioception in ACL augmented patients has been previously reported, there is no study assessing biological healing advantages of the graft after the ACL augmentation procedure.

HYPOTHESIS

Selected ACL augmentation for partial tears can accelerate the healing process of the grafted tendon, which promotes better biomechanical recovery of the tendon, compared with conventional ACL reconstruction of complete tears.

STUDY DESIGN

Controlled laboratory study.

METHODS

Two rat models were established in this study: an ACL augmentation partial tear model and conventional ACL reconstruction for a complete tear. Biological assessments of cellularity and angiogenesis were measured by hematoxylin and eosin staining and immunostaining, respectively. Additionally, rat-specific type III collagen and α-smooth muscle actin were evaluated by immunohistochemical staining to analyze the healing process, whereas anti-rat neurofilament antigen was assessed to examine proprioceptive recovery. Biological assessments of the augmented and reconstructed grafts were conducted postoperatively at week 2, whereas biomechanical testing was performed postoperatively at week 8.

RESULTS

An increase in cellularity and angiogenesis was observed in the augmented grafts compared with the conventionally reconstructed grafts. Also, increased amounts of rat-specific type III collagen, α-smooth muscle actin, and anti-rat neurofilament antigen were expressed in the augmented grafts. Biomechanical testing showed that failure to load was significantly higher in the augmentation group compared with the conventional reconstruction group (augmentation, 15.9 ± 1.0; reconstruction, 7.0 ± 1.3; P < .01).

CLINICAL RELEVANCE

Selected ACL augmentation could be a good choice for the repair of partial ACL injury by preserving the uninjured portion of the ACL, which in turn could maintain the anatomic position of the ligament and its biomechanical function.