Long-term effect of removal of knee joint loading on cartilage quality evaluated by delayed gadolinium-enhanced magnetic resonance imaging of cartilage.

OBJECTIVE: Ankle fracture patients were used as a model to study the long-term effect of the removal of joint loading on knee cartilage quality in human subjects. DESIGN: The knees of 10 patients with ipsilateral ankle fractures were investigated using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) at the time of ankle injury. After 6 weeks' prescribed unloading of the affected leg, but no restrictions regarding knee movement, the cast was removed from the ankle and the patient underwent a second dGEMRIC examination. Physiotherapy was then initiated. A third dGEMRIC examination was performed 4 months after remobilization, and a final examination 1 year after the injury. RESULTS: Baseline T1Gd values for the 10 patients were within a narrow range. No significant change in mean T1Gd was observed after 6 weeks' prescribed unloading, but the T1Gd range had increased significantly. Four months after remobilization, the mean T1Gd was significantly lower than in the previous examinations, and the range remained significantly broader than at baseline. At the 1-year follow-up, the mean T1Gd was almost identical to the value after remobilization, and the T1Gd range still showed a significant increase compared to the baseline investigation. CONCLUSIONS: Removal of knee cartilage loading for 6 weeks resulted in a measurable effect on the cartilage matrix, as evidenced by a broader T1Gd range. A decrease in mean T1Gd was observed 4 months after remobilization. These differences persisted a year after injury compared to baseline.

Association between delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and joint space narrowing and osteophytes: a cohort study in patients with partial meniscectomy with 11 years of follow-up.

OBJECTIVE: To examine the association between the relaxation time (T1Gd) of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and grade of tibiofemoral joint space narrowing (JSN) and osteophytosis 11 years later, in a cohort of meniscectomized patients. DESIGN: Patients (n = 45) aged 35-50 who had undergone an arthroscopic partial medial meniscectomy 1-6 years earlier, due to degenerative meniscal tear, were examined using dGEMRIC. These patients had no cartilage changes defined as deep clefts or visible bone at the time of arthroscopy. Eleven years later (12-16 years after surgery) 34 of these subjects (76%) were evaluated by weight-bearing knee radiography, and tibiofemoral joint changes were graded according to the Osteoarthritis Research Society International Atlas. RESULTS: Lower T1Gd in the medial compartment was associated with higher grade of medial JSN (grade 0, 351 ms; grade 1, 386 ms; grade 2, 342 ms; grade 3, 259 ms [P for trend < 0.001]) and more osteophytosis (score 0, 371 ms; score 1, 389 ms; score 2, 354 ms; score 3, 289 ms; score 4, 265 ms; score 5, 275 ms [P for trend = 0.001]). Lower T1Gd in the lateral compartment was associated with higher grade of lateral JSN (grade 0, 436 ms; grade 1, 346 ms [P for trend = 0.026]). CONCLUSION: The current study suggests that lower T1Gd measured with dGEMRIC of medial and lateral femoral cartilage is associated with higher grade of JSN 11 years later, and medially, also with more osteophytosis.

Self-efficacy, physical activity and health-related quality of life in middle-aged meniscectomy patients and controls.

Our purpose was to examine self-efficacy of knee function, physical activity (PA) and health-related quality of life (HRQoL) in post-meniscectomy patients and controls as well as to explore the impact of gender and the association between outcomes. Ninety-nine post-meniscectomy patients (27% women), mean age 44.5 years, mean (range) of follow-up time 3 (1-5) years, and 94 controls (34% women), mean age 45 years, completed the following questionnaires: the Knee Self-Efficacy Scale (K-SES(ABC) ), the Physical Activity Scale (PAS) and the Short Form-36 (SF-36). Patients scored lower than controls in K-SES(ABC) and in the SF-36 subscales Physical Functioning and Bodily Pain (P≤0.002). Forty-six percent of the patients had resumed pre-injury PA, but current PA did not differ between the groups. In the patients, K-SES(ABC) correlated strongly with four physical SF-36 subscales and one mental scale (Vitality) (r(s) =0.56-0.85, P<0.001) and moderately with three subscales: (r(s) =0.35-0.46, P<0.001) and with PAS (r(s) =0.42, P<0.001). Females scored lower than males in K-SES(ABC) (P=0.006) and in four SF-36 subscales (P<0.04), but reported similar PA as men. We conclude that meniscectomy in middle-aged individuals may lead to lower self-efficacy of knee function, a sedentary lifestyle and poorer HRQoL.

Effects of functional exercise training on performance and muscle strength after meniscectomy: a randomized trial.

Muscular deficits and functional limitations have been found years after meniscectomy of the knee. The purpose of this randomized controlled trial was to examine the effect of functional exercise training on functional performance and isokinetic thigh muscle strength in middle-aged patients subsequent to meniscectomy for a degenerative tear. Four years after meniscectomy, 45 patients (29 men, 16 women) were randomized to functional exercise training, supervised by a physical therapist, three times weekly for 4 months or to no intervention. The exercise program comprised of postural stability training and functional strength and endurance exercises for leg and trunk muscles. Outcomes were three functional performance tests and isokinetic muscle strength. Thirty patients (16 exercisers/14 controls) completed the study. Compared with control patients, the exercise group showed significant improvement in one-leg hop (change 8 vs 2 cm; P=0.040), hamstrings strength 60 degrees /s (P=0.033), and quadriceps endurance 180 degrees /s (P=0.001). Functional exercise training was well tolerated and improved functional performance and thigh muscle strength in this group of middle-aged subjects with a previous degenerative meniscal injury and partial meniscectomy.

Relationship between cartilage glycosaminoglycan content (assessed with dGEMRIC) and OA risk factors in meniscectomized patients.

OBJECTIVE: To study the relationship between cartilage integrity, assessed with [delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC)] and epidemiologic risk factors for knee osteoarthritis (OA) in meniscectomized patients. METHODS: Body mass index (BMI) was calculated in 45 patients (16 women), mean age 46, who underwent an arthroscopic medial meniscectomy 1-6 years earlier. The cartilage glycosaminoglycan (GAG) content was estimated by dGEMRIC Index and tests of isokinetic muscle strength and functional performance (one-leg hop test) were conducted. RESULTS: BMI ranged from 20.0 to 34.3 (mean: 26.5). The dGEMRIC Index was 14.4% lower in the medial index compartment (374+/-61 ms, mean+/-SD) than in the lateral reference compartment (437+/-59 ms, mean+/-SD) (P<0.001). The dGEMRIC Index of the medial diseased compartment correlated positively with both knee flexor (r=0.50, P=0.001) and knee extensor strength (r=0.47, P=0.001) relative to body weight and with the one-leg hop test (r=0.42, P=0.004). Furthermore, a negative correlation was found between the dGEMRIC Index of the medial compartment and BMI (r=-0.35, P=0.019). No significant correlations were found in the lateral reference compartment. CONCLUSION: The lower dGEMRIC Index of the medial compartment suggests decreased cartilage GAG content after medial meniscectomy, indicating an early stage OA. Furthermore, results suggest that overweight is a factor that deteriorates cartilage, whereas strong and co-ordinated thigh muscles may have a protective effect on the cartilage integrity.