Ultrasonographic measurement of the distal femoral cartilage thickness in patients with unilateral transtibial amputation

The Reliability of Suprapatellar Transverse Sonographic Assessment of Femoral Trochlear Cartilage Thickness in Healthy Adults

OBJECTIVES

To determine the intrasession reliability of femoral cartilage thickness measurements using sonography and extend the pool of normative data for cartilage thickness measurements assessed by sonography.

METHODS

A total of 77 healthy participants (55 men, 22 women), with an average age of 43 ± 18 (mean ± standard deviation) years, volunteered. Resting suprapatellar sonography was used to image trochlear cartilage thickness on 2 separate occasions a maximum of 7 days apart. Reliability was evaluated with intraclass correlation coefficients, Bland-Altman analysis, standard error of measurement, and the smallest real difference. Normative data was assessed using linear, multiple regression models and independent group t tests.

RESULTS

The test-retest level of agreement at all locations was high (intraclass correlation coefficient, 0.779-0.843), which increased to high-very high in young adults (intraclass correlation coefficient, 0.884-0.920). The standard error of measurement was 8.2% to 8.3% at all locations and reduced further to 5.4% to 6.3% in younger adults. The smallest real difference was between 22.8% and 23.1% for the full sample and 14.9% and 17.5% in young adults only. Multiple regression analyses demonstrated that age, weight, female sex, and a high physical activity frequency could significantly predict cartilage thickness at all locations (P < .05); however, female sex was the only significant independent predictor in all models (all P < .01). Females also had thinner cartilage at all locations (P < .01).

CONCLUSION

Suprapatellar sonography demonstrates high intratester reliability and measurement precision and is a promising method to assess trochlear cartilage thickness. Being female may impact femoral cartilage thickness more than other potential risk factors for knee osteoarthritis such as age, weight, and high physical activity frequency.

Ultrasonographic evaluation of the ankle after unilateral traumatic lower limb amputations

BACKGROUND

Unilateral lower limb amputation can alter the tissue morphology leading to increase future risk of degenerative secondary disorders.

METHODS

Thirty-four consecutive male patients with unilateral lower limb amputations of different levels and 34 well matched male controls were included. To explore whether the ankles of traumatic lower limb amputees were undergoing morphological changes, three different tissue types i.e. talar cartilage, plantar fascia and Achilles tendon thicknesses in the intact limb of the lower limb amputee and healthy controls were measured by using ultrasound.

RESULTS

Plantar fascia was found to be thicker (p=0.013) and talar cartilage was thinner (p<0.001) on the intact sides of the patients than those of the controls. Achilles tendon thickness was found to be similar. In patients group, plantar fascia thickness was positively correlated with age (r=0.601, p<0.001), BMI (r=0.454, p=0.007) and durations of amputation (r=0.443, p=0.009) and prosthetic use (r=0.429, p=0.011). Achilles tendon thickness was positively correlated with durations of amputation (r=0.338, p=0.05) and prosthetic use (r=0.468, p=0.005). In controls group, talar cartilage thickness was negatively correlated with age (r=-0.640, p<0.001) and BMI (r=-0.401, p=0.019).

CONCLUSIONS

The talar cartilage seemed to be thinner and the plantar fascia to be thicker on the intact sides of the unilateral limb amputees.

Ultrasonographic measurement of the femoral cartilage thickness in patients with transfemoral amputation

OBJECTIVE

To compare the distal femoral cartilage thickness of the non-amputee sides in patients who had unilateral transfemoral amputation with those of healthy subjects by using ultrasound.

METHODS

Thirty transfemoral amputees (27 male, 3 female) and 30 age-, sex-, and body mass index-matched healthy controls were included. Functional usage of the prosthesis was evaluated by using Houghton score. The cartilage thickness was measured from the following midpoints; medial femoral condyle (MFC), intercondylar area, and lateral femoral condyle.

RESULTS

Thirty patients with unilateral transfemoral amputation (mean age; 38.6 ± 9.5 years) and 30 healthy controls (mean age; 38.4 ± 9.4 years) were included. Although femoral cartilage thicknesses were found to be lower for all measurements in the amputees, the difference reached significance only in the MFC (p= 0.031). In the patient group, cartilage thickness values did not correlate with age, duration of amputation, daily walking time, stump length or Houghton score.

CONCLUSION

The distal femoral cartilage thickness seems to be decreased medially on the non-amputee sides of the transfemoral amputees when compared with the healthy subjects. Further studies concerning the follow-up designs, functional parameters and osteoarthritis scales are awaited.

Ultrasonographic assessment of the quadriceps muscle and femoral cartilage in transtibial amputees using different prostheses

BACKGROUND

In patients with lower limb amputations, gait alteration, increased loading on the intact extremity, and use of prosthesis may lead to joint degeneration.

OBJECTIVE

To explore the effects of prosthesis type on quadriceps muscle and distal femoral cartilage thicknesses in transtibial amputees.

STUDY DESIGN

A cross-sectional study.

METHODS

A total of 38 below-knee amputees were enrolled in the study, of which 13 patients were using vacuum system type prosthesis and 25 patients were using silicon liner pin system prosthesis. Patients' femoral cartilage and quadriceps muscle thickness measurements were performed using musculoskeletal ultrasound.

RESULTS

When compared with the intact sides, cartilage and rectus femoris, vastus intermedius, and vastus medialis muscle thickness values were significantly decreased on the amputee sides (all p < 0.05). Clinical characteristics and ultrasound measurements were similar between the two groups except the lateral and medial femoral condyle thicknesses, thinner in the silicon liner pin system users (both p < 0.05).

CONCLUSION

The distal femoral cartilage and quadriceps muscle thicknesses were found to be decreased on the amputated sides, and the negative impact on the cartilage seemed to be worse in the silicon liner pin system users.

CLINICAL RELEVANCE

This study might provide another argument as regards the preference of vacuum system type prosthesis to prevent possible knee osteoarthritis due to cartilage thinning in adult transtibial amputees.

Comparison of Intact Knee Cartilage Thickness in Patients with Traumatic Lower Extremity Amputation and Nonimpaired Individuals

OBJECTIVE

The aim of this study was to assess the femoral articular cartilage thickness of the intact knee in patients with traumatic lower extremity amputation compared with nonimpaired individuals.

DESIGN

A total of 30 male patients with traumatic lower extremity amputation (mean [SD] age, 31.2 [6.3] yrs) and a random sample of 53 age-matched and body mass index-matched male nonimpaired individuals (mean [SD] age, 29.8 [6.3] yrs) participated in the study. Exclusion criteria were age younger than 18 yrs, history of significant knee injury, previous knee surgery, or rheumatic disease. The femoral articular cartilage thickness was measured using ultrasound at the midpoints of the medial condyle, the intercondylar notch, and the lateral condyle. Ultrasonographic cartilage measurement was performed on the intact side of the patients with amputation and on both sides of the nonimpaired individuals.

RESULTS

The femoral articular cartilage thickness of the intact knees of the patients with amputation was significantly decreased at the lateral and medial condyles compared with the nonimpaired individuals (P < 0.05). There was no significant difference in the measurements at the intercondylar notch between the patients with amputation and the nonimpaired individuals (P > 0.05).

CONCLUSIONS

There was a premature cartilage loss in the intact limb knee of the patients with traumatic amputation. This result supports the view that patients with traumatic lower extremity amputation are at increased risk for developing knee osteoarthritis in the intact limb.