Effects of second-generation and indoor sports surfaces on knee joint kinetics and kinematics during 45° and 180° cutting manoeuvres,and exploration using statistical parametric mapping and Bayesian analyses

Sport Sciences for Health - The aim of the current investigation was to examine the influence of second-generation (2G) and indoor surfaces on knee joint kinetics, kinematics, frictional and muscle...     

Posterior-anterior weight-bearing radiograph in 15° knee flexion in medial osteoarthritis

OBJECTIVE: To evaluate the degree of knee flexion at which: (1) degenerative joint space narrowing is best seen, (2) the tibial plateau is best visualized and (3) the tibiofemoral angle is most correct, in order to assess the degree of flexion in the anteroposterior radiographic view that is most useful for assessing medial compartment osteoarthritis (OA) of the knee. DESIGN AND PATIENTS: We compared the conventional extended view of the knee and views at 15 degrees, 30 degrees, and 45 degrees of flexion with respect to joint space narrowing, alignment of the medial tibial plateau (MTP), and tibiofemoral angles in 113 knees of 95 patients with medial osteoarthritis of the knee (22 men, 73 women; mean age 67 years). RESULTS: At the midpoint and the narrowest point of the medial compartment, joint space narrowing values at 15 degrees, 30 degrees, and 45 degrees of flexion of the knee were smaller than that of the conventional extended view. Superimposition of the margins of the tibial plateau was satisfactory in 12% of patients in the conventional extended view, in 36% at 15 degrees of flexion, in 20% at 30 degrees of flexion, and in 19% at 45 degrees of flexion of the knee. When the knee was at 15 degrees of flexion there was a smaller difference in the tibiofemoral angle, in comparison with the knee extended, than was the case at 30 degrees and 45 degrees of flexion in patients with medial OA. CONCLUSION: A posteroanterior view with 15 degrees of flexion of the knee was able to detect joint space narrowing accurately, to achieve good alignment of the MTP in the medial compartment, and to reduce the difference in tibiofemoral angle compared with a view of the knee in conventional extension, and may be an alternative view in cases of medial OA of the knee.     

Is bicompartmental knee arthroplasty more favourable to knee muscle strength and physical performance compared to total knee arthroplasty?

Purpose

Bicompartmental knee arthroplasty features bone and ligament sparing as unicompartmental knee arthroplasty and is presumably better in the recovery of muscle strength and function compared to total knee arthroplasty (TKA) though not previously reported in the literature. The aim of the study was to compare isokinetic knee muscle strength and physical performance in patients who underwent either bicompartmental knee arthroplasty or TKA.

Methods

Each of 24 patients (31 knees) was prospectively examined preoperatively, at 6 and 12 months after each surgery. Isokinetic knee extensor and flexor strength as well as position sense were measured using the Biodex system. Timed up and go test, stair climbing test, and the 6-min walk test were used to assess physical performance. The results of each group were also compared with those from the corresponding healthy control, respectively.

Results

Demography showed significant difference in the mean age between bicompartment (54.8 ± 5.6 years) and TKA groups (65.7 ± 6.7 years). Comparing between the two groups, knee extensor and flexor torque, hamstring/Quadriceps ratio, position sense, and physical performance were not significantly different preoperatively, at 6 and 12 months after surgery. In intra-group analysis, muscle strength and position sense at each time point were not different in both groups. In physical performance, both groups resulted in improvement in the 6-min walk test, and only TKA group showed enhancement in stair climbing test.

Conclusions

Although theoretically plausible, bicompartmental knee arthroplasty was not superior in knee muscle strength and physical performance at 1 year compared with total knee arthroplasty.

Level of evidence

II.     

Relationship between knee alignment and T1ρ values of articular cartilage and menisci in patients with knee osteoarthritis

Objective

To assess the relationship between knee alignment and subregional T1ρ values of the femorotibial cartilage and menisci in patients with mild (Kellgren–Lawrence grade 1) to moderate (KL3) osteoarthritis (OA) at 3 T.

Materials and methods

26 subjects with a clinical diagnosis of KL1-3 OA were included and subdivided into three subgroups: varus, valgus, and neutral. All subjects were evaluated on a 3 T MR scanner. Mann–Whitney and Wilcoxon signed rank tests were performed to determine any statistically significant differences in subregional T1ρ values of femorotibial cartilage and menisci among the three subgroups of KL1-3 OA patients.

Results

Medial femoral anterior cartilage subregion in varus group had significantly higher (p < 0.05) T1ρ values than all cartilage subregions in valgus group. Medial tibial central cartilage subregion had significantly higher T1ρ values (p < 0.05) than lateral tibial central cartilage subregion in varus group. The posterior horn of the medial meniscus in neutral group had significantly higher T1ρ values (p < 0.0029) than all meniscus subregions in valgus group.

Conclusion

There exists some degree of association between knee alignment and subregional T1ρ values of femorotibial cartilage and menisci in patients with clinical OA     

What did the ankle say to the knee? Estimating knee dynamics during landing — A systematic review and meta-analysis

BackgroundLanding-based measures of the knee are often used to assess risk of anterior cruciate ligament (ACL) injury and inform prevention strategies. There is less understanding of the ankle's influence on knee measures during landing.Objective1. Examine interactions of dynamic ankle measures alongside various subject and task characteristics on knee dynamics in vertical landing and 2. Determine whether ankle measures alone can estimate dynamic knee measures associated with ACL injury risk.DesignSystematic review and meta-analysis.MethodsElectronic databases Medline, EMBASE, CINAHL, Web of Science and Cochrane were screened for studies that included measurement of initial contact angles and internal joint moments of both the ankle and knee during landing in uninjured individuals.Results28 studies were included for analysis. Using 1144 landing trials from 859 individuals, RRelief F algorithm ranked dynamic ankle measures more important than landing task and subject characteristics in estimating knee dynamics. An adaptive boosting model using four dynamic ankle measures accurately estimated knee extension (R² = 0.738, RMSE = 3.65) and knee abduction (R² = 0.999, RMSE = 0.06) at initial contact and peak knee extension moment (R² = 0.988, RMSE = 0.13) and peak knee adduction moment (R² = 1, RMSE = 0.00).ConclusionsDynamic ankle measures can accurately estimate initial contact angles and peak moments of the knee in vertical landing, regardless of landing task or individual subject characteristics. This study provides a theoretical basis for the importance of the ankle in ACL injury prevention.     

No difference in anterior knee pain between a fixed and a mobile posterior stabilized total knee arthroplasty after 7.9 years

Purpose

The presence of anterior knee pain remains one of the major complaints following total knee arthroplasty (TKA). Since the introduction of the mobile TKA, many studies have been performed and only a few show a slight advantage for the mobile. In our short-term follow-up study, we found less anterior knee pain in the posterior stabilized mobile knees compared to the posterior stabilized knees. The concept of self-alignment and the results from our short-term study led us to form the hypothesis that the posterior stabilized mobile knee leads to a lower incidence of anterior knee pain compared to the posterior stabilized fixed knee. This study was designed to see whether this difference remains after 7.9 years in the follow-up. A secondary line of enquiry was to see whether one was superior to the other regarding pain, function, quality of life and survival.

Methods

This current report is a 6–10-year (median 7.9 years) follow-up study of the remaining 69 patients with a cemented three-component TKA for osteoarthritis in a prospective, randomized, double-blinded clinical trial.

Results

In the posterior stabilized group, five of the 40 knees (13 %) versus five of the 29 posterior stabilized mobile group (17 %) experienced anterior knee pain. No differences were observed with regard to ROM, VAS, Oxford 12-item knee questionnaire, SF-36, HSS patella, Kujala or the AKSS score. Patients with anterior knee pain reported more pain, lower levels of the AKSS, HSS patella and the Kujala scores than the patients without anterior knee pain.

Conclusion

In the current clinical practice, the appearance of anterior knee pain persists as a problem; simply changing to a mobile bearing does not seem to be the solution. The posterior stabilized mobile total knee did not sustain the advantage of less anterior knee pain, compared with the posterior stabilized fixed total knee arthroplasty.

Level of evidence

Therapeutic study, Level II.     

Does meniscal pathology alter gait knee biomechanics and strength post-ACL reconstruction?

Purpose

Individuals following anterior cruciate ligament reconstruction (ACLR) with concomitant meniscal pathology have a higher risk of developing knee osteoarthritis (OA) compared to those with isolated ACLR. Knee extensor weakness and altered dynamic knee joint biomechanics have been suggested to play a role in the development of knee OA following ACLR. This study investigated whether these factors differ in people following ACLR who have concomitant meniscal pathology compared to patients with isolated ACLR.

Methods

Thirty-three patients with isolated ACLR and 34 patients with ACLR and meniscal pathology underwent strength and gait assessment 12–24 months post-operatively. Primary measures were peak isometric knee extensor torque and knee adduction moment (peak and impulse). Secondary measures included peak knee flexion moment and knee kinematics (sagittal and transverse).

Results

There were no between-group differences in knee extensor strength [mean difference (95 % CI) 0.09 (?0.23 to 0.42) Nm/kg, n.s.], peak knee adduction moment [?0.02 (?0.54 to 0.49) Nm/(BW × HT) %, n.s.] or knee adduction moment impulse [0.01 (?0.15 to 0.17) Nm/(BW × HT) %, p = n.s.]. No between-group differences were found for any secondary measures.

Conclusions

No evidence was found to suggest that the higher prevalence of OA in patients with ACLR and meniscal pathology compared to patients with isolated ACLR is attributed to reduced knee muscle strength or altered knee joint biomechanics assessed 1–2 years post-surgery. Given that there is a higher incidence of knee OA in patients with concomitant meniscal pathology and ACLR, further investigation is needed so that population-specific rehabilitation protocols can be developed.

Level of evidence

III.

     

Does total knee arthroplasty modify flexion axis of the knee?

Purpose

To prospectively investigate whether preoperative functional flexion axis in patients with osteoarthritis- and varus-alignment changes after total knee arthroplasty and whether a correlation exists both between preoperative functional flexion axis and native limb deformity.

Methods

A navigated total knee arthroplasty was performed in 108 patients using a specific software to acquire passive joint kinematics before and after implant positioning. The knee was cycled through three passive range of motions, from 0° to 120°. Functional flexion axis was computed using the mean helical axis algorithm. The angle between the functional flexion axis and the surgical transepicondylar axis was determined on frontal (α ^F) and axial (α ^A) plane. The pre- and postoperative hip-knee-ankle angle, related to femur mechanical axis, was determined.

Results

Postoperative functional flexion axis was different from preoperative only on frontal plane, while no differences were found on axial plane. No correlation was found between preoperative α ^A and native limb deformity, while a poor correlation was found in frontal plane, between α ^F and preoperative hip-knee-ankle angle.

Conclusions

Total knee arthroplasty affects functional flexion axis only on frontal plane while has no effect on axial plane. Preoperative functional flexion axis is in a more varus position respect to the transepicondylar axis both in pre- and postoperative conditions. Moreover, the position of the functional axis on frontal plane in preoperative conditions is dependent on native limb alignment, while on axial plane is not dependent on the amount of preoperative varus deformity.

Level of evidence

IV.     

Can standing knee radiographs predict chondral lesions in young- and middle-aged population?

Purpose

The aim of the study is to investigate the correlation between arthroscopic findings and joint space width on the standing knee radiographs at various flexion degrees in the young- and middle-aged patients with complaints of knee pain.

Methods

Middle-aged patients with complaint of knee pain ongoing more than 6 months and failure in conservative treatment methods were included. Weight-bearing full extension, 30 and 45° of flexion radiographs were obtained. Joint space width was calculated on radiograms. Arthroscopy was performed to evaluate the chondral pathologies. Correlation analysis was performed.

Results

Fourty-three patients (18 female, 25 male) with a mean age of 44.6 (20–63) were included. Mean joint space width was 4.87 mm ± 1.45 (2–10) mm in medial and 5.43 mm ± 1.47 (1–9) in lateral on standing extension radiographs. In 30° flexion radiographs, mean joint space width was 4.33 mm ± 1.25 (1.5–7.5) in medial and 5.36 mm ± 1.69 (1–9) in lateral. In 45° flexion radiographs, medial joint space was 4.28 mm ± 1.59 (2–9) in medial and 5.15 mm ± 1.59 (1.5–9) in lateral. In arthroscopic evaluation, one knee had grade 1 (2.3 %), three knees had grade 2 (7 %), nine knees had grade 3 (20.9 %), and twelve knees had grade 4 (27.9 %) lesions in the medial compartment. In the lateral compartment, two knees had grade 3 (4.7 %) and one knee had grade 4 lesion (2.3 %). Radiological data did not correlate with the arthroscopic findings.

Conclusion

Standing knee radiographs do not correlate with the arthroscopic findings in the middle-aged population with chondral lesions in knee joint.

Level of evidence

Case series with no comparison group, Level IV.     

Radiographic clues to the unstable knee: are findings of trochlear dysplasia on lateral knee radiographs reliable and predictive of patellar dislocation?

Emergency Radiology - Trochlear dysplasia (TD) is a key predisposing risk factor for patellar instability (PI) and lateral patellar dislocation (LPD) injuries. It is useful to understand the...     

Navigation-based tibial rotation at 90° of flexion is associated with better range of motion in navigated total knee arthroplasty

Purpose

In clinical practice, people with better femorotibial rotation in the flexed position often achieve a favourable postoperative maximum flexion angle (MFA). However, no objective data have been reported to support this clinical observation. In the present study, we aimed to investigate the correlation between the amount of intraoperative rotation and the pre- and postoperative flexion angles.

Methods

Fifty-five patients with varus osteoarthritis undergoing computer-assisted posterior-stabilized total knee arthroplasty (TKA) were enrolled. After registration, rotational stress was applied towards the knee joint, and the rotational angles were recorded by using a navigation system at maximum extension and 90° of flexion. After implantation, rotational stress was applied for a second time, and the angles were recorded once more. The MFA was measured before surgery and 1 month after surgery, and the correlation between the amount of femorotibial rotation during surgery and the MFA was statistically evaluated.

Results

Although the amount of tibial rotation at maximum extension was not correlated with the MFA, the amount of tibial rotation at 90° of flexion after registration was positively correlated with the pre- and postoperative MFA (both p < 0.005). However, no significant relationship was observed between the amount of tibial rotation after implantation and the postoperative MFA (n.s.).

Conclusion

The results showed that better femorotibial rotation at 90° of flexion is associated with a favourable postoperative MFA, suggesting that the flexibility of the surrounding soft tissues is an important factor for obtaining a better MFA, which has important clinical relevance. Hence, further evaluation of navigation-based kinematics during TKA may provide useful information on MFA.

Level of evidence

Diagnostic studies, development of diagnostic criteria in a consecutive series of patients, and a universally applied “gold” standard, Level II.

     

Test–retest reliability and variability of knee adduction moment peak,impulse and loading rate during walking

BackgroundPrevious studies have reported good test-retest reliability for peak knee adduction moment (KAM) during walking. However, reliability of other KAM measurements has not been established.Research questionWhat is the test-retest reliability of peak KAM, KAM impulse, and KAM loading rate measurements during walking in knee-healthy individuals?MethodsData from 32 knee-healthy participants were analysed in this test-retest reliability study. Various KAM measurements were reported for two sessions with kinematic and kinetic data obtained from a motion capture system synchronised with force plates, with a median of 1 week between sessions.ResultsFor all KAM measures, intra-class correlation coefficients were above 0.90 and their lower bound 95 % confidence limits exceeded 0.81. However, absolute measurement variability differed across measures, with normalized SEM (8 %–15 %), normalized MDC₉₅ (20 %–40 %), intra-session MAD (10 %–18 %), and inter-session MAD (12 %–22 %) varying over a 2-fold range. Overall and first peak KAM, KAM impulse over 50 % stance, and KAM loading rate (15 frame window) showed ≤10 % and ≤15 % intra- and inter-session MAD, respectively.SignificanceThis study provided previously undefined test-retest reliability estimates for various KAM measures during walking. Researchers and clinicians should not assume that the various aspects of the KAM curve share similar reliability.     

Is triaxial accelerometer reliable in the evaluation and grading of knee pivot-shift phenomenon?

Purpose

Dynamic laxity is clinically demonstrated with the pivot-shift (PS) test. Recently, a new system that measures the acceleration of the tibia during the PS test was validated. The goal of the present study was to use the accelerometer “KiRA” to evaluate the efficacy of measuring PS.

Methods

Between 2010 and 2011, a total of 100 patients with anterior cruciate ligament (ACL) lesions were enrolled. They underwent surgical reconstruction of the ACL. Among them, 30 patients were re-evaluated at least 6 months after surgery. Each patient underwent a clinical examination (Lachman test, anterior drawer test, and PS test) and then was subjected to an instrumental examination: KT1000 evaluation to quantify the Lachman test and KiRA to quantify the PS test.

Results

The accelerometer found a positive acceleration difference in favour of the pathologic knee. In the 100 patients evaluated preoperatively, the analysed acceleration parameters on the pathologic knee were found to be significantly different with respect to the contralateral joint. Correlating the clinical subjective data with numerical data, we identified mean reference values for every grade of the PS test (negative, glide, and clunk).

Conclusion

Our experience showed us that the use of KiRA accelerometer for quantitative measurement of the PS is both promising and reliable. The efficacy of this instrument is strictly related to an inevitable learning curve and to proper execution of the test. It has the value of being easy to set up and easy to use in both the clinic and the operating room.     

Is previous knee arthroscopy related to worse results in primary total knee arthroplasty?

According to literature, knee arthroscopy is a minimal invasive surgery performed for minor surgical trauma, reduced morbidity and shortens the hospitalization period. Therefore, this type of surgery before total knee arthroplasty (TKA) could be considered a minor procedure with minimum postoperative complication. A retrospective and cohort series of 1,474 primary TKA was performed with re-assessment after a minimum follow-up period of 2 years: 1,119 primary TKA had no previous surgery (group A) and 60 primary TKA had arthroscopic debridement (group B). All the patients underwent a clinical and radiological evaluation as well as IKS scores. Statistical analysis of postoperative complications revealed that group B had a higher postoperative complication rate (P < 0.01). In this group, 30% of local complications were re-operated and 8.3% of these cases underwent revision TKA (P < 0.01). The mean interval between arthroscopy and primary TKA was 53 months. However, statistical analysis did not reveal a direct correlation between arthroscopy/primary TKA interval and postoperative complications/failures (P = 0.55). The Kaplan–Meier survival curves showed a survival rate of 98.1 and 86.8% at 10 years follow-up for groups A and B, respectively. Our data allow us to conclude that previous knee arthroscopy should be considered a factor related to postoperative primary TKA outcomes as demonstrated by the higher rate of postoperative complications and failures (P < 0.001) as well as a worse survival curve than group A.     

Comparison of 180° and 360° data acquisition for determination of left ventricular function from gated myocardial perfusion tomography and gated blood pool tomography

The purpose of this study was to address the issue of 180° versus 360° data collection for left ventricular ejection fraction (LVEF) and left ventricular volume measurements using gated myocardial perfusion tomography (gMPT) and gated blood pool tomography (gBPT). Thirty patients with known coronary artery disease were injected in a random sequence with 925 MBq of technetium-99m tetrofosmin and, within 2 days, with 740 MBq of ^99mTc-labelled human serum albumin. gMPT and gBPT were acquired using 360° data collection and reconstructed by filtered backprojection using all the acquired projection images and separately using only projection images acquired from 45° LPO to 45° RAO. In order to have the same global count densities, the counts in the 360° data set were redistributed using binomial deviates just before reconstruction. After reorientation along the left ventricular long axis, LVEF and left ventricular volumes were calculated using fully automatic algorithms. Twenty-eight patients also underwent planar radionuclide angiocardiography (PRNA) on the same day as the gBPT. For the gMPT studies, the correlation between 180° data collection and 360° data collection was excellent (r>0.98). Bland-Altman analysis revealed small systematic and random differences (<6%) between 180° and 360°. For the gBPT studies, the correlation between 180° data collection and 360° data collection was very good (r>0.93). However, Bland-Altman analysis revealed systematic differences of 26% and random differences of 17%. When PRNA was used as a reference, the best results were obtained with gMPT acquired using 180° data, while the worst results were obtained with gBPT acquired using 180° data. In conclusion, when evaluating LVEF and left ventricular volumes from gMPT, either 180° or 360° orbits can be used. However, 360° data acquisition is recommended when evaluating LVEF and left ventricular volumes from gBPT.     

Influence of TNF-α and biomechanical stress on matrix metalloproteinases and lysyl oxidases expressions in human knee synovial fibroblasts

Purpose

It was reported that not only ACL but also the synovium may be the major regulator of matrix metalloproteinases (MMPs) in synovial fluids after ACL injury. In order to further confirm whether synovium is capable of regulating the microenvironment in the process of ACL injury, the complicated microenvironment of joint cavity after ACL injury was mimicked and the combined effects of mechanical injury and inflammatory factor [tumour necrosis factor-α (TNF-α)] on expressions of lysyl oxidases (LOXs) and MMPs in synovial fibroblasts derived from normal human synovium were studied.

Methods

Human normal knee joint synovial fibroblasts were stimulated for 1–6 h with mechanical stretch and inflammatory factor (TNF-α). Total RNA was harvested, reverse transcribed and assessed by real-time polymerase chain reaction for the expression of LOXs and MMP-1, 2, 3 messenger RNAs. MMP-2 activity was assayed from the collected culture media samples using zymography.

Results

Compared to control group, our results showed that 6 % physiological stretch increased MMP-2 and LOXs (except LOXL-3), decreased MMP-1 and MMP-3; injurious stretch (12 %) decreased LOXs (except LOXL-2)and increased MMP-1, 2 and 3; the combination of injurious stretch and TNF-α decreased LOXs and increased MMP-1, 2 and 3 in synovial fibroblasts in a synergistical manner.

Conclusion

This study demonstrated that combination of mechanical injury and inflammatory factors up-regulated the expressions of MMPs and down-regulated the expressions of LOXs in synovial fibroblasts, eventually alter the balance of tissue healing. Thus, synovium may be involved in regulating the microenvironment of joint cavity. Based on the mechanism, early interventions to inhibit the production of MMPs or promote the production of LOXs in the synovial fibroblasts should be performed to facilitate the healing of tissue.     

Are hip and knee kinematics and training load characteristics relate to pain intensity and physical function level in runners with Patellofemoral Pain?

BackgroundPatellofemoral pain (PFP) is the most common running-related injury. Altered hip and knee kinematics and increases in weekly distance and running pace are often associated with PFP development and exacerbation.Research questionAre altered movements and training load characteristics (weekly distance and running pace) relate to pain intensity or physical function level in runners with PFP?MethodsForty recreational runners with PFP (20 males and 20 females) participated in this cross-sectional observational study. Three-dimensional hip and knee kinematics were quantified during the stance phase of running. Weekly distance was defined as the average weekly kilometers of running and running pace as the average pace of the activity measured as minutes per kilometer. A visual analogue scale was used to evaluate worst knee pain during the last week. The anterior knee pain scale (AKPS) was used to evaluate knee functional score. A Pearson correlation matrix was used to investigate the association between each dependent variable (worst pain in the last week and AKPS score) and the independent variables (knee and hip kinematics, weekly distance and running pace).ResultsThere was no significantly correlation between kinematic variables, pain and functional score for both males and females separately and combined. Weekly distance (km/week) was found to positively correlate to pain intensity (r = 0.452; p < 0.05) in females with PFP. A simple linear regression revealed that weekly distance was significant predictor emerged of pain in females with PFP. Females exhibited significantly greater peak hip adduction and hip adduction ROM than the males and males had significantly greater running pace compared to females.SignificanceWeekly distance should be considered in the clinical context during rehabilitation of PFP in females runners aiming at pain reduction.