An open-label, single-arm trial of cryoneurolysis for improvements in pain, activities of daily living and quality of life in patients with symptomatic ankle osteoarthritis.

Objective: Cryoneurolysis, cold-induced reversible conduction block of peripheral nerves, is an effective treatment for reducing knee osteoarthritis (OA) symptoms and opioid use following knee arthroplasty. There are however, limited data concerning its use for ankle OA. Our aim was to assess clinically significant long-term symptomatic relief of ankle OA with cryoneurolysis. Method: This single-center, open-label trial included participants aged >18 years with radiographic tibiotalar OA, unilateral ankle pain ≥5/10 on Numerical Rating Scale (NRS), and with no ankle surgery within 6-months of screening. Following ultrasound-guided cryoneurolysis of nerves in the participant's pain distribution (sural, saphenous, superficial and/or deep fibular nerves), outcomes were assessed at clinic visits (6, 12 and 24-weeks) and by telephone interview (3, 9, 18-weeks). The primary endpoint was change in Foot and Ankle Outcome Score (FAOS) (pain subscale) at 12-weeks. Change in quality of life (FAOS-QoL), activities of daily living (FAOS-ADL), NRS-pain, and physical performance measures were also assessed. Longitudinal mixed models were constructed to evaluate changes from baseline at 6, 12- and 24-weeks post-treatment. Results: Forty participants enrolled (50% female, mean â€‹± â€‹SD age 63.0 â€‹± â€‹12.8 years). At 12-weeks post treatment, FAOS-pain (20.8, p â€‹< â€‹0.0001), ADL (18.1, p â€‹= â€‹0.0003), QoL (19.9, p â€‹= â€‹0.0003) and NRS-pain (-2.6, p â€‹< â€‹0.0001) were significantly improved from baseline. No difference in 40-m fast-paced walking test was detected at 12-weeks post-treatment (-1.2sec, p â€‹= â€‹0.59). For all outcomes, similar findings were observed at 6- and 24-week visits. Conclusion: Cryoneurolysis resulted in statistically significant improvements in ankle pain, physical function and QoL for up to 24-weeks in participants with unilateral, symptomatic ankle OA.

Foot and ankle pain and risk of incident knee osteoarthritis and knee pain: Data from the Multicentre Osteoarthritis Study.

OBJECTIVES: To examine whether foot and/or ankle pain increases the risk of knee OA. DESIGN: We utilised longitudinal data from the Multicentre Osteoarthritis Study (MOST); a community-based cohort of risk factors for knee OA. Participants without frequent knee pain (clinic visit only) and radiographic knee OA (RKOA) at baseline and, with no evidence of inflammatory musculoskeletal disease and a history of knee-related surgery were followed for up to 84-months for incident outcomes; i) RKOA (Kellgren-Lawrence (KL) ≥2), ii) symptomatic RKOA (RKOA and frequent pain in the same knee) and iii) frequent knee pain only. At baseline, ankle and foot symptoms were assessed, with knee radiographs and symptoms also assessed at 30, 60 and 84-months. Our exposures included baseline ankle, foot, and ankle and foot pain (participant-level). Associations between foot and/or ankle pain and incident outcomes were assessed using multiple logistic regression, with adjustment for participant characteristics and ankle/foot pain. RESULTS: No statistically significant associations were observed between ankle, foot and, ankle and foot pain and incident RKOA, respectively. Ankle pain with (2.30, 95% CI 1.13 to 4.66) and without foot pain (OR: 2.53, 95% CI 1.34 to 4.80) were associated with increased odds of incident symptomatic RKOA and frequent knee pain. No statistically significant associations were observed between foot pain and these outcomes. CONCLUSIONS: Ankle pain should be a focus point, more so than foot pain, in the management of knee OA. Future studies should include additional ankle joint-specific symptom questions to better elucidate the knee OA biomechanical pathway.

Step Rate and Worsening of Patellofemoral and Tibiofemoral Joint Osteoarthritis in Women and Men: The Multicenter Osteoarthritis Study.

OBJECTIVE: To determine the association of self-selected walking step rate with worsening of cartilage damage in the patellofemoral (PF) joint and tibiofemoral (TF) joint compartments at a 2-year follow-up visit. METHODS: The Multicenter Osteoarthritis Study (MOST) is a prospective cohort of men and women with or at risk of knee osteoarthritis. Self-selected step rate was measured using an instrumented GAITRite walkway (CIR Systems) at the 60-month visit. Cartilage damage was semiquantitatively graded on magnetic resonance images at the 60- and 84-month visits in the medial and lateral PF and TF compartments. Step rate was divided into quartiles, and logistic regression was used to determine the association of step rate with the risk of worsening cartilage damage in men and women separately. Analyses were adjusted for age, body mass index, and knee injury/surgery. RESULTS: A total of 1,089 participants were included. Mean ± SD age was 66.9 ± 7.5 years, mean ± SD body mass index was 29.6 ± 4.7 kg/m2 , and 62.3% of the participants were women. Women with the lowest step rate had increased risk of lateral PF (risk ratio [RR] 2.1 [95% confidence interval (95% CI) 1.1-3.8]) and TF (RR 1.8 [95% CI 1.1-2.9]) cartilage damage worsening 2 years later compared to those with the highest step rate. Men with the lowest step rate had increased risk of medial TF cartilage damage worsening 2 years later (RR 2.1 [95% CI 1.1-3.9]). CONCLUSION: Lower step rate was associated with increased risk of cartilage damage worsening in the lateral PF and TF compartments in women and worsening medial TF joint damage in men. Future research is necessary to understand the influence of step rate manipulation on joint biomechanics in women and men.

Influence of Antagonistic Hamstring Coactivation on Measurement of Quadriceps Strength in Older Adults.

BACKGROUND: There is limited understanding of how antagonist muscle coactivation relates to measurement of strength in both individuals with and without knee osteoarthritis (KOA). OBJECTIVE: This study sought to determine whether hamstring coactivation during a maximal quadriceps activation task attenuates net quadriceps strength. DESIGN: Cross-sectional cohort analysis was conducted using data from the 60-month visit of the Multicenter Osteoarthritis Study (MOST). SETTING: Laboratory. PARTICIPANTS: A sample of 2328 community-dwelling MOST participants between the ages of 55 and 84 years, with or at elevated risk for KOA, completed the 60-month MOST follow-up visit. Of these, 1666 met inclusion criteria for the current study. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE(S): Quadriceps strength; percentage of combined hamstring coactivation (HC), medial HC, and lateral HC. Quadriceps and hamstring strength were assessed using an isokinetic dynamometer. Surface electromyography was used to assess muscle activation patterns. General linear models, adjusted for age, BMI, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Kellgren-Lawrence (KL) grade and study site, modeled the relationship between antagonist hamstring coactivation and quadriceps strength. RESULTS: Men had significantly greater quadriceps strength (P < .001), history of knee injury (P < .001) and surgery (P = .002), and greater presence of varus malalignment (P < .001). Women had greater pain (P < .001) and proportion of KL grade ≥2 (P = .017). Gender-specific analyses revealed combined HC (P = .013) and lateral HC inversely associated with quadriceps strength in women (P = .023) but not in men (combined HC P = .320, lateral HC P = .755). A nonlinear association was detected between quadriceps strength and medial HC. Assessment of quartiles of medial HC revealed the third quartile had reduced quadriceps strength when compared to the lowest quartile of coactivation in both men and women. CONCLUSIONS: Hamstring coactivation attenuates measured quadriceps strength in women with or at elevated risk for KOA. LEVEL OF EVIDENCE: II.

Predicting meniscal tear stability across knee-joint flexion using finite-element analysis.

PURPOSE: To analyse the stress distribution through longitudinal and radial meniscal tears in three tear locations in weight-bearing conditions and use it to ascertain the impact of tear location and type on the potential for healing of meniscal tears. METHODS: Subject-specific finite-element models of a healthy knee under static loading at 0°, 20°, and 30° knee flexion were developed from unloaded magnetic resonance images and weight-bearing, contrast-enhanced computed tomography images. Simulations were then run after introducing tears into the anterior, posterior, and midsections of the menisci. RESULTS: Absolute differences between the displacements of anterior and posterior segments modelled in the intact state and those quantified from in vivo weight-bearing images were less than 0.5 mm. There were tear-location-dependent differences between hoop stress distributions along the inner and outer surfaces of longitudinal tears; the longitudinal tear surfaces were compressed together to the greatest degree in the lateral meniscus and were most consistently in compression on the midsections of both menisci. Radial tears resulted in an increase in stress at the tear apex and in a consistent small compression of the tear surfaces throughout the flexion range when in the posterior segment of the lateral meniscus. CONCLUSIONS: Both the type of meniscal tear and its location within the meniscus influenced the stresses on the tear surfaces under weight bearing. Results agree with clinical observations and suggest reasons for the inverse correlation between longitudinal tear length and healing, the inferior healing ability of medial compared with lateral menisci, and the superior healing ability of radial tears in the posterior segment of the lateral meniscus compared with other radial tears. This study has shown that meniscal tear location in addition to type likely plays a crucial role in dictating the success of non-operative treatment of the menisci. This may be used in decision making regarding conservative or surgical management.

Effect of Knee Extensor Strength on Incident Radiographic and Symptomatic Knee Osteoarthritis in Individuals With Meniscal Pathology: Data From the Multicenter Osteoarthritis Study.

OBJECTIVE: High knee extensor strength may be important to protect against the development of knee osteoarthritis (OA) in populations at elevated risk, such as individuals with meniscal pathology. We investigated the extent to which high knee extensor muscle strength was associated with a decreased risk of developing radiographic or symptomatic knee OA in individuals with medial meniscal pathology. METHODS: We studied knees that at the baseline visit of the Multicenter Osteoarthritis Study had medial meniscal pathology but did not have radiographic knee OA (373 knees in 373 participants) or symptomatic knee OA (combination of radiographic knee OA and frequent knee symptoms; 531 knees in 531 participants). Isokinetic knee extensor strength was measured at baseline, and participants were followed for development of incident radiographic knee OA or incident symptomatic knee OA at 84 months. Separate binomial regression analyses with robust SEs adjusted for age, history of knee surgery, physical activity level, and clinic site were conducted for men and women. RESULTS: High knee extensor strength (normalized by allometric scaling) was associated with a reduced risk of radiographic knee OA in women (relative risk [RR] 0.52, 95% confidence interval [95% CI] 0.29-0.94) but not in men (RR 0.56, 95% CI 0.27-1.16). High knee extensor strength did not protect against the development of symptomatic knee OA, either in women or men. CONCLUSION: The results only partly confirm the hypothesis that high knee extensor muscle strength protects against later development of knee OA in individuals with medial meniscal pathology.

Diagnostic performance of 3D standing CT imaging for detection of knee osteoarthritis features.

OBJECTIVE: To determine the diagnostic performance of standing computerized tomography (SCT) of the knee for osteophytes and subchondral cysts compared with fixed-flexion radiography, using MRI as the reference standard. METHODS: Twenty participants were recruited from the Multicenter Osteoarthritis Study. Participants' knees were imaged with SCT while standing in a knee-positioning frame, and with postero-anterior fixed-flexion radiography and 1T MRI. Medial and lateral marginal osteophytes and subchondral cysts were scored on bilateral radiographs and coronal SCT images using the OARSI grading system and on coronal MRI using Whole Organ MRI Scoring. Imaging modalities were read separately with images in random order. Sensitivity, specificity and accuracy for the detection of lesions were calculated and differences between modalities were tested using McNemar's test. RESULTS: Participants' mean age was 66.8 years, body mass index was 29.6 kg/m(2) and 50% were women. Of the 160 surfaces (medial and lateral femur and tibia for 40 knees), MRI revealed 84 osteophytes and 10 subchondral cysts. In comparison with osteophytes and subchondral cysts detected by MRI, SCT was significantly more sensitive (93 and 100%; p < 0.004) and accurate (95 and 99%; p < 0.001 for osteophytes) than plain radiographs (sensitivity 60 and 10% and accuracy 79 and 94%, respectively). For osteophytes, differences in sensitivity and accuracy were greatest at the medial femur (p = 0.002). CONCLUSIONS: In comparison with MRI, SCT imaging was more sensitive and accurate for detection of osteophytes and subchondral cysts than conventional fixed-flexion radiography. Additional study is warranted to assess diagnostic performance of SCT measures of joint space width, progression of OA features and the patellofemoral joint.

Vibration platform training in women at risk for symptomatic knee osteoarthritis.

OBJECTIVE: To determine whether a platform exercise program with vibration is more effective than platform exercise alone for improving lower limb muscle strength and power in women ages 45 to 60 with risk factors for knee osteoarthritis (OA). DESIGN: Randomized, controlled study. SETTING: Academic center. PARTICIPANTS: A total of 48 women ages 45-60 years with risk factors for knee OA (a history of knee injury or surgery or body mass index ≥25 kg/m(2)). INTERVENTIONS: Subjects were randomly assigned to a twice-weekly lower limb exercise program (quarter squat, posterolateral leg lifts, calf raises, step-ups, and lunges) on either a vertically vibrating platform (35 Hz, 2 mm) or a nonvibrating platform. MAIN OUTCOME MEASUREMENTS: Change in isokinetic quadriceps strength, leg press power, and stair climb power by 12 weeks. RESULTS: A total of 39 of 48 enrolled participants completed the study (26 vibration and 13 control exercise). Nine participants discontinued the study after randomization mainly because of a lack of time. No intergroup differences in age, body mass index, or activity level existed. Isokinetic knee extensor strength did not significantly improve in either group. Leg press power improved by 92.0 ± 69.7 W in the vibration group (P < .0001) and 58.2 ± 96.2 W in the control group (P = .0499) but did not differ between groups (P = .2262). Stair climb power improved by 53.4 ± 64.7 W in the vibration group (P = .0004) and 55.7 ± 83.3 W in the control group (P = .0329) but did not differ between groups (P = .9272). CONCLUSIONS: Whole body vibration platforms have been marketed for increasing strength and power. In this group of asymptomatic middle-aged women with risk factors for knee OA, the addition of vibration to a 12-week exercise program did not result in significantly greater improvement in lower limb strength or power than did participation in the exercise program without vibration.

Central versus lower body obesity distribution and the association with lower limb physical function and disability.

OBJECTIVE: To determine whether fat distribution in obese adults is significantly associated with decreased function and increased disability. DESIGN: Cross-sectional epidemiologic analysis. SETTING: Multicenter, community-based study. PARTICIPANTS: Multicenter Osteoarthritis Study participants included adults ages 50-79 years at high risk of developing or already possessing knee osteoarthritis. A total of 549 men and 892 women from the Multicenter Osteoarthritis Study who had a body mass index ≥ 30 kg/m² and who underwent dual energy x-ray absorptiometry (DEXA) scans were included in these analyses. Exclusion criteria included bilateral knee replacements, cancer, or other rheumatologic disease. METHODS: Body fat distribution was determined using baseline DEXA scan data. A ratio of abdominal fat in grams compared with lower limb fat in grams (trunk:lower limb fat ratio) was calculated. Participants were divided into quartiles of trunk:lower limb fat ratio, with highest and lowest quartiles representing central and lower body obesity, respectively. Backward elimination linear regression models stratified by gender were used to analyze statistical differences in function and disability between central and lower body obesity groups. MAIN OUTCOME MEASURES: Lower limb physical function measures included 20-meter walk time, chair stand time, and peak knee flexion and extension strength. Disability was assessed using the Late Life Function and Disability Index. RESULTS: Trunk:lower limb fat ratio was not significantly associated with physical function or disability in women or men (P value .167-.972). Total percent body fat (standardized ß = -0.1533 and -0.1970 in men and women, respectively) was a better predictor of disability when compared with trunk:lower limb fat ratio (standardized ß = 0.0309 and 0.0072). CONCLUSIONS: Although fat distribution patterns may affect clinical outcomes in other areas, lower limb physical function and disability do not appear to be significantly influenced by the distribution of fat in obese older adults with, or at risk for, knee osteoarthritis. These data do not support differential treatment of functional limitations based on fat distribution.

Effect of thigh strength on incident radiographic and symptomatic knee osteoarthritis in a longitudinal cohort.

OBJECTIVE: To assess whether knee extensor strength or hamstring:quadriceps (H:Q) ratio predicts risk for incident radiographic tibiofemoral and incident symptomatic whole knee osteoarthritis (OA) in adults ages 50-79 years. METHODS: We followed 1,617 participants (2,519 knees) who, at the baseline visit of the Multicenter Osteoarthritis (MOST) Study, did not have radiographic tibiofemoral OA and 2,078 participants (3,392 knees) who did not have symptomatic whole knee OA (i.e., did not have the combination of radiographic OA and frequent knee symptoms). Isokinetic strength was measured at baseline, and participants were followed for development of incident radiographic tibiofemoral OA, or incident symptomatic whole knee OA at 30 months. Generalized estimating equations accounted for 2 knees per subject, and multivariable models adjusted for age, body mass index (BMI), hip bone mineral density, knee surgery or pain, and physical activity score. RESULTS: In the studies of incident radiographic and incident symptomatic knee OA, mean +/- SD ages were 62.4 +/- 8.0 years and 62.3 +/- 8.0 years, respectively, and mean +/- SD BMI scores were 30.6 +/- 5.8 kg/m(2) and 30.2 +/- 5.5 kg/m(2), respectively. Knee extensor strength and H:Q ratio at baseline significantly differed between men and women. Neither knee extensor strength nor the H:Q ratio was predictive of incident radiographic tibiofemoral OA. Compared with the lowest tertile, the highest tertile of knee extensor strength protected against development of incident symptomatic whole knee OA in both sexes (adjusted odds ratio 0.5-0.6). H:Q ratio was not predictive of incident symptomatic whole knee OA in either sex. CONCLUSION: Thigh muscle strength does not appear to predict incident radiographic OA, but does seem to predict incident symptomatic knee OA.

Knee extensor strength does not protect against incident knee symptoms at 30 months in the multicenter knee osteoarthritis (MOST) cohort.

OBJECTIVE: Knee extensor weakness has not been associated consistently with the risk for incident knee pain. Additionally, the balance of hamstring-to-quadriceps strength (H:Q ratio) may affect risk and has not been studied. The authors determined whether knee extensor weakness or muscle imbalance is a risk factor for development of frequent knee pain or stiffness and whether the effect is modified by lower limb alignment. DESIGN: Observational study. SETTING: Community. PARTICIPANTS: Community-dwelling adults ages 50-79 years with or at risk of knee osteoarthritis based on obesity, knee injury, or surgery. A total of 1269 knees from women and 1006 knees from men without frequent knee symptoms at baseline and with 15- or 30- month follow-up outcome data were included. ASSESSMENT OF RISK FACTORS: Isokinetic knee extensor and flexor strength as well as radiographic hip-knee-ankle alignment were measured at baseline. H:Q ratio was dichotomized, with normal being considered to be >/=0.6. MAIN OUTCOME MEASUREMENTS: Frequent knee symptoms at 15- or 30-month follow-up (frequent knee pain, aching, or stiffness on most days of the past month reported at both telephone contact just before and at visit). RESULTS: Mean +/- SD age was 62.2 +/- 8.0 years and mean body mass index (BMI) was 30.1 +/- 5.4 kg/m(2). Mean peak knee extensor strength (KES) was 132.6 +/- 42.4 and 76.9 +/- 25.3 N.m in men and women, respectively. Approximately 50% of knees in men and 59% of knees in women had an H:Q ratio <0.6. A total of 307 of 2275 eligible knees developed frequent knee symptoms at follow-up. Logistic regression controlling for age, BMI, femoral neck bone mineral density, activity score, and baseline Kellgren Lawrence grade revealed that neither KES nor H:Q ratio predicted the development of knee symptoms in gender-stratified or combined analyses. These results were unaffected by adjusting for lower limb alignment. CONCLUSIONS: Neither concentric quadriceps strength nor H:Q ratios predicted the development of frequent knee symptoms at 15- or 30-month follow-up in this cohort.

Other surgical techniques for osteoarthritis.

Prior to the need for arthroplasty, there are numerous surgical options for management of osteoarthritis. This chapter is aimed at addressing the current state of knowledge and practice regarding: (1) arthroscopic lavage and debridement; (2) articular surface stimulation by means of penetration or microfracture; (3) high tibial osteotomies; (4) preventative ligament stabilization and joint distraction; and (5) transplantation of soft tissue, osteochondral, chondrocyte and matrix implantation as well as use of growth factors. Evidence is reviewed regarding the outcomes and indications for each of these operations, and where evidence is lacking, needs for further research are indicated. Future directions building upon promising early results of articular surface regeneration are also described.