The effect of kinetic factors of dynamic knee valgus on patellofemoral pain: A systematic review and meta-analysis.

The speculation of dynamic knee valgus (DKV) correlates with kinetic changes in the frontal plane that increased loading patellofemoral joint (PFJ). Therefore, it is the purpose of this systematic review and meta-analysis study is the effect of kinetic factors DKV on patellofemoral pain (PFP). The search strategy was carried out in the electronic databases of Cochrane Library, PubMed, Springer Link, Science Direct, Scopus. Studies limited to the period 2000 to 2020 were extracted. The quality of study was assessment by modified Downs and Black checklist. Mean and standard deviation were also used to calculate the effect size. There were selected 8 articles for the systematic review and Meta-analysis. The results showed that in PFP patients compared to healthy individuals have increase knee abduction moment (SMD = 0.75; 95% CI = [0.47 to 1.02]) and impulse (SMD = 0.79; 95% CI = [0.50 to 1.07]). Furthermore, PFP patients compared to healthy individuals have decrease onset (SMD = -0.60; 95% CI = [-1.03 to -0.17]) and during (SMD = -0.93; 95% CI = [-1.57 to -0.29]) gluteus medius (GMED); vis-à-vis, PFP patients compared to healthy individuals have increase onset (SMD = 0.10; 95% CI = [-0.34 to 0.54]) and during (SMD = 0.29; 95% CI = [-0.15 to 0.73]) adductors longus (AL). As a result; PFP patients compared to healthy individuals show decrease co-contraction GMED/AL (SMD = -1.03; 95% CI = [-1.83 to -0.24]). The kinetic factors of DKV of leading to PFJ contact area decreases and the loading in a smaller contact area on PFJ in the outer part of the patella. Eventually, this abnormal distribution of contact pressure leads to etiology and osteoarthritis of the PFP.

Manejo no quirúrgico de la artrosis de rodilla: ¿Son efectivos los medicamentos orales complementarios? / Non-surgical management of knee osteoarthritis: are complementary oral medications effective?

La artrosis es una enfermedad progresiva de las articulaciones sinoviales que causa dolor, impotencia funcional, discapacidad, y degeneración progresiva de la articulación. En sus tratamientos, sobre todo en etapas tempranas, existen distintas intervenciones para evitar tanto su desarrollo y progresión como también para lograr un adecuado manejo de los síntomas, y hay tratamientos médicos orales no convencionales con evidencia controvertida. El objetivo de este trabajo es proporcionar una actualización, dirigida a especialistas en Ortopedia y Traumatología, respecto a la evidencia actual sobre las terapias complementarias orales en el tratamiento de la artrosis de rodilla. Se hace referencia a los métodos fármacológicos complementarios más usados y estudiados, mencionando el método de acción y las consecuencias estudiadas sobre la artrosis de rodilla. Se finaliza con una tabla de recomendaciones basada en evidencia actual.

Osteoarthritis (OA) is a progressive disease of the synovial joints that causes pain, functional impairment, disability, and progressive degeneration of the joint. Regarding its treatments, especially in early stages, there are different interventions to avoid its development and progression and also to achieve an adequate management of symptoms, and there are unconventional oral medical treatments with controversial evidence. The objective of the present paper is to provide an update, to specialists in Orthopedics and Traumatology, regarding the current evidence on complementary oral therapies in the treatment of knee osteoarthritis. References are made to the most widely used and studied complementary pharmacological methods, mentioning the method of action and the consequences studied on knee osteoarthritis. The article ends with a table of recommendations based on current evidence.

Electromyographic comparison of vastus medialis obliquus facilitatory versus vastus lateralis inhibitory kinesio taping in athletes with patellofemoral pain: A randomized clinical trial.

BACKGROUND: Patellofemoral pain (PFP) is among the most common orthopedic complications afflicting active young people. Diminished coordination of the vastii, delayed activation of the vastus medialis obliquus (VMO), and decreased VMO-to-vastus lateralis (VL) activity ratio are well documented as underlying causes of PFP. This study compares the effects of VMO facilitatory kinesio tape (KT) versus VL inhibitory KT on electromyographic (EMG) activity of the vastii, balance, and pain in athletes with PFP. METHODS: In this single-blind randomized clinical trial, thirty-two female athletes with PFP (mean age 26.33 ± 5.93 years) were randomly assigned to VMO facilitatory KT (n = 16) or VL inhibitory KT (n = 16) groups. In the facilitatory group, a Y-shaped strip of KT at 25% of its available tension was attached from the origin of the VMO to its insertion and in the inhibitory group, an insertion-to-origin Y-shaped strip of KT at 15% of its available tension was applied on the VL. Pain intensity, dynamic balance, and EMG data were assessed respectively with a visual analogue scale, the modified Star Excursion Balance Test, and an EMG telemetry system, before and immediately after KT application. RESULTS: Pain intensity decreased and dynamic balance improved significantly after taping in both groups, and VMO: VL activity ratio increased significantly in the VL group. However, none of the parameters differed significantly between groups. CONCLUSIONS: Both VMO facilitatory and VL inhibitory KT can improve pain and balance, while the inhibitory technique might be more effective in regulating the VMO to VL activity ratio in athletes with PFP.

[Ultrasound anatomy and needle-knife insertion approach of common tendon lesions in knee osteoarthritis based on meridian sinew theory].

OBJECTIVE: To explore the ultrasonic anatomical characteristics and needle-knife insertion approach of common tendon lesions in knee osteoarthritis (KOA), so as to provide the references for accurate release of KOA by needle- knife along tendon lesions based on meridian sinew theory. METHODS: Sixty patients with one-knee KOA were selected. High-frequency musculoskeletal ultrasound was used to collect sonograms at the anatomical positions of "Hedingci" "Binwaixia" "Binneixia" and "Yinlingshang". The anatomic levels were marked on the sonograms. The anatomic levels and sonographic features of lesions were compared and analyzed, and the relevant data of needle-knife simulation approach was measured. RESULTS: The "Hedingci" lesions were mainly located at the attachment of quadriceps tendon to patella and suprapatellar bursa. The "Binwaixia" and "Binneixia" lesions were mainly located at the attachment of retinaculum patellae laterale and retinaculum patellae mediale to patella and infrapatellar fat pad. The "Yinlingshang" lesions were mainly located at the attachment of goose foot tendon to medial tibial condyle and bursa of goose foot. With "Hedingci" as an example, when the needle-knife entry point was 1 cm above the patella, the attachment of quadriceps tendon to patella was released, and the average depth of needle-knife was (3.60±0.10) cm, and the needle body was perpendicular to the skin. The average depth of needle-knife for releasing suprapatellar bursa was (2.35±0.17) cm, and the needle body was 45° towards head. CONCLUSION: The musculoskeletal ultrasound could clearly show the local detailed anatomical level, ultrasonic characteristics and anatomical level of common tendon lesions of KOA, and could improve the accuracy of needle-knife along tendon lesions with non-direct vision, which has important reference value for needle-knife medical standardization and standardized operation.

Image-guided intervention in the management of chronic patellar tendinopathy with calcification: a three-pronged approach.

Patellar tendinopathy is a common cause of knee pain and functional impairment in athletes. It is commonly managed using conservative measures such as physiotherapy, but cases that are refractory to such treatment may require a more invasive approach. Various forms of image-guided injection therapy have been described in the literature. We present a case of successful treatment of chronic patellar tendinopathy with calcification with the first reported use of a three-pronged image-guided approach, consisting of dry needling, high volume image-guided injection (but at a reduced dose) and barbotage applied in a single sitting. The patient reported resolution of symptoms persisting to 1 year postprocedure. We suggest that this management option, if supported by further positive research findings, could be used in the future in the management of certain cases of patellar tendinopathy with calcification where conservative measures have failed.

Association Between T2* Relaxation Times Derived From Ultrashort Echo Time MRI and Symptoms During Exercise Therapy for Patellar Tendinopathy: A Large Prospective Study.

BACKGROUND: Exercise therapy is considered preferential treatment for patellar tendinopathy (PT). However, there is conflicting evidence for structural patellar tendon adaptation in response to exercise therapy and its association with symptoms is weak. PURPOSE: To assess the association between 1) T2* relaxation times and symptom severity; 2) baseline T2* and clinical outcome; and 3) longitudinal T2* changes and clinical outcome in athletes with PT performing exercise therapy. STUDY TYPE: Randomized controlled clinical trial. SUBJECTS: Seventy-six athletes (18-35 years) with clinically diagnosed and ultrasound-confirmed PT. FIELD STRENGTH/SEQUENCE: 3D gradient echo sequence (3.0 T). ASSESSMENT: Patients were enrolled in a randomized trial of progressive tendon-loading exercises (PTLE) versus eccentric exercise therapy (EET). Symptoms were assessed using the Victorian Institute of Sports Assessment (VISA-P) questionnaire. 3D-Ultrashort echo time (UTE)-MRI was acquired at baseline, 12 and 24 weeks. Voxel-wise T2* relaxation times were quantified using mono-exponential and bi-exponential models. T2* analysis was performed in three patellar tendon tissue compartments representing: aligned collagen, degenerative tissue, and interface. STATISTICAL TESTS: Adjusted general linear, mixed-linear models, and generalized estimating equations. RESULTS: We included 76 patients with PT (58 men, mean age 24 ± 4 years); 38 in the PTLE-group and 38 in the EET-group, of which 57 subjects remained eligible for analysis. T2* relaxation times were significantly associated with VISA-P in degenerative and interface tissues of the patellar tendon. No association was found between baseline T2* and VISA-P after 24 weeks (P > 0.29). The estimated mean T2* in degenerative tissue decreased from 14 msec (95%CI: 12-16) at baseline to 13 msec (95%CI: 11-15) at 12 weeks and to 13 msec (95%CI: 10-15) at 24 weeks. The significant decrease in T2* from baseline to 24 weeks was associated with improved clinical outcome. DATA CONCLUSION: Tissue-specific T2* relaxation times, identified with 3D-UTE-MRI, decreased significantly in athletes with patellar tendinopathy performing exercise therapy and this decrease was associated with improved clinical outcome. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 4.

Quadriceps architecture in individuals with patellofemoral pain: A systematic review.

OBJECTIVES: To identify differences in architectural parameters (size, fiber/pennation angle, fiber length, and echogenicity) of the quadriceps muscle, as a whole or any individual part of it, using imaging techniques in individuals with patellofemoral pain (PFP) compared to contralateral, asymptomatic limb or separate control group. BACKGROUND: Quadriceps muscles imbalance and weakness were proposed as risk factors for developing PFP. Although the muscle architecture (size, pennation/fiber angle and fiber length) is highly associated with skeletal muscle strength, it is not clear whether atrophy or any changes in architectural parameters of the quadriceps are presented in the PFP patients. METHODS: Observational studies in which the total size of the quadriceps or individual parts of it were measured using imaging techniques in the PFP patients were included in this review. Electronic databases (PubMed, SCOPUS, PEDro, CINAHL, WOS, and EMBASE) were searched between January 1990 and December 2019 with no restriction of language. Study selection and data extraction and quality assessment were conducted by two independent reviewers. RESULTS: Five cross-sectional studies were eligible to include in this review. Three out of five included studies that assessed the total size of the quadriceps and reported no significant differences between the PFP and healthy control group. Two out of five of the studies assessed the total size of the quadriceps between the symptomatic and asymptomatic limb of the PFP patients and reported the statistical difference between limbs. Only one study measured the fiber angle of the VMO muscle at the patella. Controversial results were found between studies that assessed the size of individual parts of the quadriceps. CONCLUSION: Due to the controversial results of the included studies, this systematic review failed to draw a conclusion on the role of quadriceps atrophy in PFP pathology. The limitation in PFP literature considering pennation/fiber angle, echogenicity and fiber length of individual parts of the quadriceps muscle, rises the need for research that focuses on the biomechanical properties of the quadriceps in PFP patients.

The Benefit of Perineural Injection Treatment with Dextrose for Treatment of Chondromalacia Patella in Participants Receiving Home Physical Therapy: A Pilot Randomized Clinical Trial.

Introduction: Chondromalacia patella is the degeneration of articular cartilage on the posterior facet of the patella and may indicate the onset of osteoarthritis. Conservative management is the main treatment option, and surgical intervention is considered the last option in a small percentage of patients. Perineural Injection Treatment (PIT) is a recently developed treatment option that is directed adjacent to the peripheral nerves that are the source of pathology causing neurogenic inflammation and pain. Objective: The objective of this study was to evaluate the efficacy of PIT combined with a home physical therapy program in patients with a diagnosis of chondromalacia patella compared with a control group receiving physical therapy only. Methods: Two patient groups were involved in this randomized clinical trial. The first received PIT combined with physical therapy (PIT + PT group) and the second was managed with physical therapy alone (PT group). Both groups were indicated to follow a 6-week home therapy plan afterward. The Western Ontario and McMaster Osteoarthritis Index was used to assess the patients at baseline and 6 months after therapy interventions. Results: Fifty patients (38 women and 12 men, median age 54.7 ± 14.8 years) were included; sex distribution and age did not differ between groups. Both groups had chondromalacia grade II or III, but the degree of gonarthrosis did not differ significantly between groups. The PIT + PT group outperformed PT group for pain (7.3 ± 3.5 vs. 3.2 ± 2.9 points; p < 0.010), stiffness (3 ± 1.69 vs. 1.6 ± 1.5 points; p < 0.010), and functional capacity (23.2 ± 10.7 vs. 11.1 ± 8.9 points; p < 0.010). Conclusions: Compared with physical therapy alone, PIT plus physical therapy reduced pain and stiffness and restored functional capacity. ClinicalTrials.gov Register Number #NCT03515720.

Ultrasound anatomy and needle-knife insertion approach of common tendon lesions in knee osteoarthritis based on meridian sinew theory / 中国针灸

OBJECTIVE@#To explore the ultrasonic anatomical characteristics and needle-knife insertion approach of common tendon lesions in knee osteoarthritis (KOA), so as to provide the references for accurate release of KOA by needle- knife along tendon lesions based on meridian sinew theory.@*METHODS@#Sixty patients with one-knee KOA were selected. High-frequency musculoskeletal ultrasound was used to collect sonograms at the anatomical positions of "Hedingci" "Binwaixia" "Binneixia" and "Yinlingshang". The anatomic levels were marked on the sonograms. The anatomic levels and sonographic features of lesions were compared and analyzed, and the relevant data of needle-knife simulation approach was measured.@*RESULTS@#The "Hedingci" lesions were mainly located at the attachment of quadriceps tendon to patella and suprapatellar bursa. The "Binwaixia" and "Binneixia" lesions were mainly located at the attachment of retinaculum patellae laterale and retinaculum patellae mediale to patella and infrapatellar fat pad. The "Yinlingshang" lesions were mainly located at the attachment of goose foot tendon to medial tibial condyle and bursa of goose foot. With "Hedingci" as an example, when the needle-knife entry point was 1 cm above the patella, the attachment of quadriceps tendon to patella was released, and the average depth of needle-knife was (3.60±0.10) cm, and the needle body was perpendicular to the skin. The average depth of needle-knife for releasing suprapatellar bursa was (2.35±0.17) cm, and the needle body was 45° towards head.@*CONCLUSION@#The musculoskeletal ultrasound could clearly show the local detailed anatomical level, ultrasonic characteristics and anatomical level of common tendon lesions of KOA, and could improve the accuracy of needle-knife along tendon lesions with non-direct vision, which has important reference value for needle-knife medical standardization and standardized operation.

Correlation of T2* relaxation times of the retropatellar cartilage with tibial tuberosity-trochlea groove distance in professional soccer players.

The tibial tuberosity-trochlear groove (TT-TG) distance is a radiographic measurement that is used to quantify malalignment of the patellofemoral joint (PFJ) in cross-sectional imaging. There is an ongoing debate about the impact of the TT-TG-distance on lateral patellar instability and the initiating of cartilage degeneration. In this prospective study, the association of T2* relaxation times and TT-TG distances in professional soccer players was analyzed. 36 knees of 18 professional soccer players (age: 21 ± 2.8 years) were evaluated. Participants underwent knee MRI at 3 T. For qualitative image analysis, fat-saturated 2D PD-weighted Fast Spin Echo (FSE) and T1-weighted FSE sequences were used. For quantitative analysis, T2* measurements in 3D data acquisitions were performed. In a qualitative analysis there was no structural cartilage damage and no abnormalities of the patellar and trochlea shape. The highest T2* values (26.7 ± 5.9 ms) were observed in the central compartment of the patella. The mean TT-TG distance was 10 ± 4 mm (range 3-20 mm). There was no significant correlation between TT-TG distance and T2* relaxation times in all three compartments of the retropatellar cartilage. Our study shows that so long as patellar and trochlear morphology is normal, TT-TG distance alone does not affect the tissue structure of the retropatellar cartilage in professional soccer players.

[Clinical observation of acupuncture at tendon blockage point of quadriceps femoris muscle belly for patella femoral arthritis].

OBJECTIVE: To evaluate the clinical effect of acupuncture at tendon blockage point of quadriceps femoris muscle belly for mild to moderate patella femoral arthritis. METHODS: A total of 76 patients with mild to moderate patella femoral arthritis were randomly divided into an observation group and a control group, 38 cases in each group. The patients in the observation group were treated with acupuncture at tendon blockage point of quadriceps femoris muscle belly, and the needles were stayed for 20 min each time for twice a week; while the patients in the control group were treated with sodium hyaluronate injection into articular cavity, once a week, and both groups were treated for 4 weeks. The pain symptoms and joint function of the patients were evaluated with pain visual analogue scale (VAS) score, tenderness value of the most obvious pain point in front of the knee, and Lysholm knee function score before and one week after treatment, and the clinical effect was observed. RESULTS: After treatment, VAS scores, tenderness value of the most obvious pain point in front of the knee and Lysholm knee function scores of the two groups were improved compared with before treatment (P<0.05); the improvement of VAS score and tenderness value of the most obvious pain point in front of the knee in the observation group was more obvious than that in the control group (P<0.05). The total effective rate in the observation group was 94.7% (36/38), which was higher than 81.6% (31/38) in the control group (P<0.05). CONCLUSION: Acupuncture at tendon blockage point of quadriceps femoris muscle belly can relieve pain and improve the function of patella femoral joint for patients with patella femoral arthritis, and the clinical effect is better than that of sodium hyaluronate injected into articular cavity.

The effect of Kinesio-tape® on pain and vertical jump performance in active individuals with patellar tendinopathy.

BACKGROUND: Patellar tendinopathy is a common inflammatory condition in athletes who undergo large volumes of running and jumping. Kinesio-tape® (KT) is proposed to provide pain relief; however, its effect has not been examined on patellar tendinopathy. OBJECTIVE: To examine the effects of KT on pain modulation for active individuals with patellar tendinopathy during functional activities. METHODS: Thirteen symptomatic knees from seven college-aged females (6 bilateral; 1 unilateral) were included. Participants underwent three data collection sessions with KT, sham, and no tape (NT) in a randomized order. During the session, participants performed a maximum vertical jump, single-leg squats and isometric knee extension. The KT intervention was applied according to the KT manual and the sham utilized the same pattern without tension. Pain level was evaluated using the numeric pain scale before, during and after each activity. Function was assessed as maximum vertical jump height and maximum isometric strength. A separate repeated measures ANOVA was used to compare each dependent variable (pain level, vertical jump height, and isometric strength) among the conditions. RESULTS: Reported pain scores were significantly lower (p = 0.05) during the maximal vertical jump test for KT (3.38 ± 1.26) compared to NT (4.54 ± 2.22). Significantly lower jump heights were found under KT (17.73 ± 3.06in) during the maximum vertical jump test compared to sham (18.65 ± 2.17in, p = 0.000) and NT (18.18 ± 2.93in, p = 0.008). CONCLUSIONS: The use of the KT tape with a tendon corrective strip and muscle facilitative strip was effective for decreasing pain associated with patellar tendinopathy during jump landing but led to decreased maximum jump height. CLINICAL TRIAL IDENTIFIER: NCT04153877.

Controversial Topics in Total Knee Arthroplasty: A 5-Year Update (Part 1).

BACKGROUND: This review article examines updates to the literature during the past 5 years on numerous topics related to total knee arthroplasty which were felt to have ongoing controversy. These include the use of peripheral nerve blocks and local infiltrative analgesia, intrathecal morphine, patellar resurfacing, and bearing designs. METHODS: For each individual topic, a literature search was conducted on several databases with emphasis on studies that were published in the past 5 years. Preference was given to meta-analyses and randomized controlled trials. RESULTS: Multimodal periarticular injections may provide an equally effective analgesic effect to peripheral nerve blocks, but are also muscle sparing and less invasive. The use of intrathecal morphine in addition to periarticular injections is less desirable given the potential side effects, associated cost, and lack of clear benefit intrathecal morphine beyond the 6- to 12-hour postoperative period. Patellar resurfacing was associated with a lower rate of revision surgery, similar or potentially improved satisfaction and functional outcomes, and no increased risk of complications compared with nonresurfacing. There are no clear or notable differences between cruciate-retaining and posterior-stabilized total knee designs in terms of clinical outcomes and survivorship. Medial pivot designs theoretically recreate more normal knee kinematics compared with cruciate-retaining or posterior-stabilized designs, although superiority has not yet been clearly demonstrated and additional long-term data is necessary, particularly for survivorship. CONCLUSIONS: By analyzing the results of the aforementioned studies, surgeons can implement the most up-to-date evidence-based care when doing total knee arthroplasty surgery. However, many of these selected topics continue to have a component of ongoing controversy with no definitive conclusions developed in recent literature.

Fully automated patellofemoral MRI segmentation using holistically nested networks: Implications for evaluating patellofemoral osteoarthritis, pain, injury, pathology, and adolescent development.

PURPOSE: Our clinical understanding of the relationship between 3D bone morphology and knee osteoarthritis, as well as our ability to investigate potential causative factors of osteoarthritis, has been hampered by the time-intensive nature of manually segmenting bone from MR images. Thus, we aim to develop and validate a fully automated deep learning framework for segmenting the patella and distal femur cortex, in both adults and actively growing adolescents. METHODS: Data from 93 subjects, obtained from on institutional review board-approved protocol, formed the study database. 3D sagittal gradient recalled echo and gradient recalled echo with fat saturation images and manual models of the outer cortex were available for 86 femurs and 90 patellae. A deep-learning-based 2D holistically nested network (HNN) architecture was developed to automatically segment the patella and distal femur using both single (sagittal, uniplanar) and 3 cardinal plane (triplanar) methodologies. Errors in the surface-to-surface distances and the Dice coefficient were the primary measures used to quantitatively evaluate segmentation accuracy using a 9-fold cross-validation. RESULTS: Average absolute errors for segmenting both the patella and femur were 0.33 mm. The Dice coefficients were 97% and 94% for the femur and patella. The uniplanar, relative to the triplanar, methodology produced slightly superior segmentation. Neither the presence of active growth plates nor pathology influenced segmentation accuracy. CONCLUSION: The proposed HNN with multi-feature architecture provides a fully automatic technique capable of delineating the often indistinct interfaces between the bone and other joint structures with an accuracy better than nearly all other techniques presented previously, even when active growth plates are present.

Bilateral Patellar Stress Fractures in a Skeletally Immature Athlete: A Case Report.

CASE: This report describes the divergent course and management of bilateral patellar stress fractures in a 17-year-old skeletally immature male athlete. Beginning as bilateral incomplete tension-sided patellar fractures, the right patella healed uneventfully, whereas the left progressed to a complete, mildly displaced transverse fracture that eventually healed with nonoperative treatment measures to include temporary bracing, physical therapy, and vitamin D supplementation. CONCLUSIONS: Patellar stress fractures are exceptionally rare, particularly bilateral injuries in the pediatric population. Diligent workup is necessary for appropriate diagnosis, whereas knowledge of the salient features of these injuries is useful in treatment.

Cannulated Screw Prominence in Tension Band Wiring of Patella Fractures Increases Fracture Gapping: A Cadaver Study.

BACKGROUND: Transverse patella fractures are often treated with cannulated screws and a figure-of-eight anterior tension band. A common teaching regarding this construct is to recess the screws so that their distal ends do not protrude beyond the patella because doing so may improve biomechanical performance. However, there is a lack of biomechanical or clinical data to support this recommendation. QUESTION: In the treatment of transverse patella fractures, is there a difference between prominent and recessed cannulated screw constructs, supplemented by tension banding, in terms of gap formation from cyclic loading and ultimate load to failure? METHODS: Ten pairs of fresh-frozen cadaver legs (mean donor age, 72 years; range, 64-89 years) were randomized in a pairwise fashion to prominent or standard-length screws. In the prominent screw group, screw length was 15% longer than the measured trajectory, resulting in 4 to 6 mm of additional length. Each patella was transversely osteotomized at its midportion and fixed with screws and an anterior tension band. Gap formation was measured over 40 loaded flexion-extension cycles (90° to 5°). Ultimate load to failure was assessed with a final monotonic test after cyclic loading. Areal bone mineral density (BMD) of each patella was measured with dual energy x-ray absorptiometry (DEXA). There was no difference in BMD between the recessed (1.06 ± 0.262 g/cm) and prominent (1.03 ± 0.197 g/cm) screw groups (p = 0.846). Difference in gap formation was assessed with a Wilcoxon Rank Sum Test. Ultimate load to failure and BMD were assessed with a paired t-test. RESULTS: Patella fractures fixed with prominent cannulated screws demonstrated larger gap formation during cyclic loading. Median gap size at the end of cyclic loading was 0.13 mm (range, 0.00-2.92 mm) for the recessed screw group and 0.77 mm (range, 0.00-7.50 mm) for the prominent screw group (p = 0.039; 95% confidence interval [CI] difference of geometric means, 0.05-2.12 mm). There was no difference in ultimate failure load between the recessed screw (891 ± 258 N) and prominent screw (928 ± 268 N) groups (p = 0.751; 95% CI difference of means, -226 to 301 N). Ultimate failure load was correlated with areal BMD (r = 0.468; p = 0.046). CONCLUSIONS: In this cadaver study, when using cannulated screws and a figure-of-eight tension band to fix transverse patella fractures, prominent screws reduced the construct's ability to resist gap formation during cyclic loading testing. CLINICAL RELEVANCE: This biomechanical cadaver study found that the use of prominent cannulated screws for the fixation of transverse patella fractures increases the likelihood of interfragmentary gap formation, which may potentially increase the risk of fracture nonunion and implant failure. These findings suggest that proximally and distally recessed screws may increase construct stability, which may increase the potential for bony healing. The findings support further laboratory and clinical investigations comparing recessed screws supplemented by anterior tension banding with other repair methods that are in common use, such as transosseous suture repair.

Anterior cruciate ligament transection alters the n-3/n-6 fatty acid balance in the lapine infrapatellar fat pad.

BACKGROUND: The infrapatellar fat pad (IFP) of the knee joint has received lots of attention recently due to its emerging role in the pathogenesis of osteoarthritis (OA), where it displays an inflammatory phenotype. The aim of the present study was to examine the infrapatellar fatty acid (FA) composition in a rabbit (Oryctolagus cuniculus) model of early OA created by anterior cruciate ligament transection (ACLT). METHODS: OA was induced randomly in the left or right knee joint of skeletally mature New Zealand White rabbits by ACLT, while the contralateral knee was left intact. A separate group of unoperated rabbits served as controls. The IFP of the ACLT, contralateral, and control knees were harvested following euthanasia 2 or 8 weeks post-ACLT and their FA composition was determined with gas chromatography-mass spectrometry. RESULTS: The n-3/n-6 polyunsaturated FA (PUFA) ratio shifted in a pro-inflammatory direction after ACLT, already observed 2 weeks after the operation (0.20 ± 0.008 vs. 0.18 ± 0.009). At 8 weeks, the FA profile of the ACLT group was characterized with increased percentages of 20:4n-6 (0.44 ± 0.064 vs. 0.98 ± 0.339 mol-%) and 22:6n-3 (0.03 ± 0.014 vs. 0.07 ± 0.015 mol-%) and with decreased monounsaturated FA (MUFA) sums (37.19 ± 1.586 vs. 33.20 ± 1.068 mol-%) and n-3/n-6 PUFA ratios (0.20 ± 0.008 vs. 0.17 ± 0.008). The FA signature of the contralateral knees resembled that of the unoperated controls in most aspects, but had increased proportions of total n-3 PUFA and reduced MUFA sums. CONCLUSIONS: These findings provide novel information on the effects of early OA on the infrapatellar FA profile in the rabbit ACLT model. The reduction in the n-3/n-6 PUFA ratio of the IFP is in concordance with the inflammation and cartilage degradation in early OA and could contribute to disease pathogenesis.

Clinical results of pulsed signal therapy on patellofemoral syndrome with patellar chondropathy.

This study was designed to evaluate the effect of pulsed signal therapy (PST) on patellofemoral pain syndrome associated with patellar chondropathy. A prospective randomized double-blind placebo controlled trial included 25 patients (41 knees) between 20 and 50 years with pain due to isolated patellofemoral syndrome with chondropathy. PST group received nine 60-min daily sessions of PST treatment. Control group received the same protocol of blinded placebo treatment. The main outcome was change from baseline Kujala score at 3 months. After 3 months, patients in the control group received effective treatment (placebo post-treatment). All patients were then followed, for up to 12 months. Seventeen knees (5 males and 12 females, mean age 36.7 ± 7.9) received placebo and 24 knees (8 males and 16 females, mean age 35.5 ± 8.9) received PST. By the third month, PST group exhibited a mean change from baseline of 9.63 ± 7.5 Kujala points, compared to 0.53 ± 1.8 in the placebo group (P < 0.001). A significant progressive improvement was seen in the PST group between the 3rd and 6th and between the 6th and 12th month (P < 0.016). Patients initially allocated in the control group also improved at 3 months (P < 0.001) and 6 months (P = 0.005) post-effective treatment. In conclusion, PST in patellofemoral pain syndrome with chondropathy was effective compared to placebo at 3 months, showing an important improvement of Kujala score. The improvement was progressive and maintained up to 12 months. PST is safe and should be considered as a non-invasive option for management of this condition. Bioelectromagnetics. 40:83-90, 2019. © 2019 Bioelectromagnetics Society.

Physiological, kinematic, and electromyographic responses to kinesiology-type patella tape in elite cyclists.

Kinesiology-type tape (KTT) has become popular in sports for injury prevention, rehabilitation, and performance enhancement. Many cyclists use patella KTT; however, its benefits remain unclear, especially in uninjured elite cyclists. We used an integrated approach to investigate acute physiological, kinematic, and electromyographic responses to patella KTT in twelve national-level male cyclists. Cyclists completed four, 4-minute submaximal efforts on an ergometer at 100 and 200 W with and without patella KTT. Economy, energy cost, oxygen cost, heart rate, efficiency, 3D kinematics, and lower-body electromyography signals were collected over the last minute of each effort. Comfort levels and perceived change in knee stability and performance with KTT were recorded. The effects of KTT were either unclear, non-significant, or clearly trivial on all collected physiological and kinematic measures. KTT significantly, clearly, and meaningfully enhanced vastus medialis peak, mean, and integrated electromyographic signals, and vastus medialis-to-lateralis activation. Electromyographic measures from biceps femoris and biceps-to-rectus femoris activation ratio decreased in either a significant or clinically meaningful manner. Despite most cyclists perceiving KTT as comfortable, increasing stability, and improving performance, the intervention exerted no considerable effects on all physiological and kinematic measures. KTT did alter neuromuscular recruitment, which has potential implications for injury prevention.