The Association of Vibratory Perception and Muscle Strength With the Incidence and Worsening of Knee Instability: The Multicenter Osteoarthritis Study

Nomogram in Knee Instability: 3D Gait Analysis of Knee Osteoarthritis Patients

BACKGROUND

Measures of knee stability by symptoms, physical examination, and imaging do not accurately reflect the condition of knee movement. Therefore, this study aimed to introduce a model for assessing knee stability during walking in patients with knee osteoarthritis (OA).

AIMS

Three dimensional(3D) gait analysis system was used to quantify the gait of patients and display the clinical diagnosis model of knee instability with nomogram to guide clinical diagnosis and treatment.

METHODS

This cross-sectional study performed a 3D gait analysis in 93 participants with knee OA and 40 healthy control subjects. Multiple linear regression analysis investigated the correlation between gait parameters and knee extension/flexion stability. The predicting models were built applied multinomial logistic regression analysis and calibration plot, C-index, decision curve analysis, bootstrapping validation were used to assess the predicting nomograms' clinical usefulness and internal validation.

RESULTS

Multiple linear regression analysis indicated knee extension stability was correlated with walking speed (β = 0.256, P = 0.006), knee extensor strength (β = -0.196, P = 0.03), static HKA (β = 0.218, P = 0.016), width of the femoral diaphysis (β = -0.282, P = 0.002) and WOMAC score (β = 0.281, P = 0.002); however, knee flexion stability was correlated with walking speed (β = 0.340, P < 0.001), knee flexor strength (β = -0.327, P < 0.001), posterior tibial slope (PTS) (β = 0.291, P < 0.001), knee flexion/extension range of motion (ROM) (β = 0.177, P = 0.018) and HSS score (β = -0.173, P = 0.028). We developed and internally validated a knee instability risk nomogram in patients with knee OA.

CONCLUSIONS

These results indicated that using the 3D motion analysis system is feasible to quantify knee instability. The current prediction models could serve as a reliable tool to quantify the possibility of knee instability in OA patients.

TRIAL REGISTRATION NUMBER TRN

ChiCTR2100051302; Date of registration: Sep 18, 2021; retrospectively registered.

The effect of Total resistance exercise vs. aquatic training on self-reported knee instability, pain, and stiffness in women with knee osteoarthritis: a randomized controlled trial

BACKGROUND

Knee Instability (KI) is described as a sense of knee buckling, shifting, or giving way during the weight bearing activities. High prevalence (60-80%) has been reported for KI amongst the patients with knee osteoarthritis (KOA). In this line, the present study targeted the effect of two interventions on self-reported KI and affected factors.

METHODS

In this single blind, randomized, and controlled trial, 36 patients with radiographic grading (Kellgren-Lawrence ≥ II) of KOA were selected. Patients were divided into three groups namely, aquatic (n = 12), Total Resistance exercises (TRX) (n = 12) and control (n = 12) by random. Then both 8-week TRX and aquatic exercises were carried out by experimental groups. The following measure were taken before and after interventions: Pain by visual analog scale (VAS), balance by Berg Balance Scale (BBS), quadriceps strength by dynamometer, knee flexion range of motion (ROM) by inclinometer, knee stiffness with Western Ontario and McMaster Universities Osteoarthritis (WOMAC), and self-reported KI with Felson's questionnaire.

RESULTS

The results demonstrated that KI, VAS, BBS improved over time both in TRX and aquatic groups significantly (p < 0.05), but WOMAC(stiffness), knee flexion ROM, and quadriceps strength were significantly improved over time only for TRX (p < 0.05). Post hoc test, also, showed that there were significant differences between interventions and control groups (p < 0.05) for the VAS, KI, BBS, but for WOMAC(stiffness), a significant difference was observed only between TRX and control groups (p = 0.05).

CONCLUSIONS

Although TRX and aquatic interventions had a similar effect on the patients' balance, pain and KI, TRX had more effect on WOMAC(stiffness), quadriceps strength, and knee flexion ROM than aquatic exercises.

TRIAL REGISTRATION

This study was registered in the Iranian Clinical Trial Center with the number IRCT20181222042070N1, http://www.irct.ir/trial/36221, registered 02 February 2019.

BILATERAL SENSORY DEFICITS AND WIDESPREAD HYPERALGESIA OCCUR FOLLOWING INDUCED DELAYED ONSET MUSCLE SORENESS OF THE QUADRICEPS

BACKGROUND

Unaccustomed eccentric exercise during sport or training may lead to delayed onset muscle soreness (DOMS), which has been demonstrated to influence postural control, potentially resulting in further injury. Afferent sensory input is critical to effective postural control, but little is known about somatosensory changes at the knee following induction of DOMS of the quadriceps muscle. The 'soreness' or hyperalgesia associated with DOMS has been postulated to occur because of damage to/inflammation of the exercised muscle, however, effects on central nociceptive mechanisms, which are known to induce altered postural responses, have been less studied.

PURPOSE/HYPOTHESIS

It was hypothesized that DOMS of the quadriceps muscle would result in widespread hyperalgesia and hypoesthesia at the knee. Therefore, the purpose of this study was to investigate the effects of DOMS on knee somatosensory changes in asymptomatic healthy participants.

STUDY DESIGN

Quasi-experimental cohort study.

METHODS

Thirty participants (15 males and 15 females) took part in the study. Eccentric exercise consisted of 10 sets of 10 maximum eccentric quadriceps contractions performed with the dominant knee. Outcome measures consisted of pain intensity (Visual Analog Scale), pressure pain threshold (PPT), vibration perception threshold (VPT) and proprioception, measured via threshold to detection of passive motion (TDPM) at the knee, at three different assessment time points: (1) pre-eccentric exercise; (2) immediately and (3) 48 hours post-eccentric exercise.

RESULTS

Not surprisingly, pain intensity increased and PPT of the vastus medialis and rectus femoris muscles decreased (hyperalgesia) immediately post-exercise on the exercised limb. However, at 48 hours, hyperalgesia was demonstrated at other lower extremity muscles, including bilaterally at the tibialis anterior muscles, and also at the hand. Evidence of hypoesthesia was also demonstrated. VPT and TDPM increased (worsened) ipsilaterally both immediately and 48 hours after exercise, and TDPM increased bilaterally at 48 hours. Females demonstrated greater impairment in TDPM than males at 48 hours. Expanding distribution of hyperalgesia, ipsilaterally impaired VPT and bilaterally impaired proprioception were demonstrated in the presence of DOMS.

DISCUSSION/CONCLUSION

Inflammation from unaccustomed eccentric exercise may induce neuroplastic changes in nociceptive pathways resulting in wider distribution of pain and hypoesthesia. Futures studies examining the effect of DOMS related somatosensory changes on postural control may be warranted.

LEVEL OF EVIDENCE

3.

Oral administration of N-acetyl cysteine prevents osteoarthritis development and progression in a rat model

The number of osteoarthritis patients is increasing with the rise in the number of elderly people in developed countries. Osteoarthritis, which causes joint pain and deformity leading to loss of activities of daily living, is often treated surgically. Here we show that mechanical stress promotes accumulation of reactive oxygen species (ROS) in chondrocytes in vivo, resulting in chondrocyte apoptosis and leading to osteoarthritis development in a rat model. We demonstrate that mechanical stress induces ROS accumulation and inflammatory cytokine expression in cultured chondrocytes in vitro and that both are inhibited by treatment with the anti-oxidant N-acetyl cysteine (NAC). In vivo, osteoarthritis development in a rat osteoarthritis model was also significantly inhibited by oral administration of NAC. MMP13 expression and down-regulation of type II collagen in chondrocytes, both of which indicate osteoarthritis, as well as chondrocyte apoptosis in osteoarthritis rats were inhibited by NAC. Interestingly, osteoarthritis development in sham-operated control sides, likely due to disruption of normal weight-bearing activity on the control side, was also significantly inhibited by NAC. We conclude that osteoarthritis development in rats is significantly antagonized by oral NAC administration. Currently, no oral medication is available to prevent osteoarthritis development. Our work suggests that NAC may represent such a reagent and serve as osteoarthritis treatment.

Perceived Instability Is Associated With Strength and Pain, Not Frontal Knee Laxity, in Patients With Advanced Knee Osteoarthritis

BACKGROUND

Increased varus/valgus laxity and perceived knee instability are independently associated with poor outcomes in people with knee osteoarthritis. However, the relationship between laxity and perceived instability is unclear.

OBJECTIVE

To assess whether knee extensor strength, pain, and knee laxity are related to perceived knee instability in patients with advanced knee osteoarthritis.

METHODS

This was a secondary analysis of a prospective observational cohort study of 35 patients (24 female; mean ± SD age, 60 ± 8 years; body mass index, 33 ± 5 kg/m²) with knee osteoarthritis awaiting total knee arthroplasty (36 knees). Within 1 month before arthroplasty, we measured isometric knee extension strength and self-reported knee pain (using the Knee injury and Osteoarthritis Outcome Score pain subscale). Patients rated their perception of knee instability as moderate to severe (n = 20) or slight to none (n = 15 patients, n = 16 knees) using the Knee Outcome Survey. We measured intraoperative varus/valgus knee laxity.

RESULTS

Lower knee extension strength (P = .01) and greater pain (P<.01) were associated with the perception of moderate to severe knee instability. Laxity was not related to perceived knee instability (P = .63).

CONCLUSION

Knee extension strength and pain were associated with perceived instability in people with advanced osteoarthritis. Varus/valgus laxity was not related to perceived knee instability.

LEVEL OF EVIDENCE

Level 2, prognostic. J Orthop Sports Phys Ther 2019;49(7):513-517. doi:10.2519/jospt.2019.8619.

Self-reported Instability in Knee Osteoarthritis: A Scoping Review of Literature

BACKGROUND

Knee Osteoarthritis (OA) is a disabling musculoskeletal condition among the elderly. Self-reported instability is one of the impairments associated with osteoarthritis. A complete understanding of the self-reported instability in knee OA is essential, to identify the best strategies for overcoming this impairment. The focus of this scoping review is to provide an overview of evidence supported information about the prevalence and other associated features of selfreported instability in Knee OA. A broad search of the database PubMed with keywords such as knee osteoarthritis and instability resulted in 1075 articles. After title abstract and full-text screening, 19 relevant articles are described in the review. Overall, there is less amount of published literature on this topic. Studies reported prevalence rates of more than 60% for self-reported instability in knee osteoarthritis, which causes functional deterioration and high fear of falls. The most probable causative factors for self-reported instability in knee OA were altered sensory mechanisms and decreased muscle strength.

CONCLUSION

To conclude, self-reported knee instability in knee OA requires thorough evaluation and directed treatment with further studies providing rationalistic evidence-based management strategies. The current literature regarding self-reported knee instability is summarized, highlighting the research gaps.