Award Date


Degree Type


Degree Name

Doctor of Physical Therapy (DPT)


Physical Therapy

Advisor 1

Kai-Yu Ho

First Committee Member

Merrill Landers

Second Committee Member

Daniel Young

Number of Pages



Purpose/Hypothesis: A patellar-tendon-bearing (PTB) bar is a common prosthetic design feature used in individuals with trans-tibial amputations. As the patellar tendon in the knee of residual limb is subjected to the perpendicular compressive force not commonly seen in normal tendon loading, it is possible for tendon remodeling and degeneration to occur over time; however, there is limited data to support this idea. The primary purpose of this study was to use ultrasound imaging to compare the morphological differences between tendons of the residual and intact limb in unilateral trans-tibial amputees who utilize a prosthesis with a PTB feature. We hypothesized that the patellar tendon of the residual limb would have increased thickness, increased cross-sectional area (CSA), a greater proportion of neovascularity, and decreased collagen fiber organization (i.e., reduced peak spatial frequency radius [PSFR]), when compared to the intact limb. Subjects: Twelve unilateral trans-tibial amputees (age = 53.6 ± 16.9 years; 3 females and 9 males; years after amputation = 16.7±18.2 years) who utilized a prosthesis with a PTB feature, having had it at least 1 year, and weight-bearing at least 1 hour per day. Materials/Methods: Ultrasound images of each subject’s patellar tendons were collected in a single session. Longitudinal and transverse images were taken at the proximal, distal, and mid- portion of each patellar tendon to examine thickness, CSA, neovascularity, and collagen fiber organization. Paired t-tests were used to compare the thickness, CSA, and PSFR between the residual and intact limbs. A chi-square analysis was used to compare the proportion of neovascularity between limbs. Results: There was a statistically significant difference in mid-portion CSA (residual = 113.71±18.62 mm2, intact =101.79±17.15 mm2; p = 0.008), and proximal thickness (residual = 4.76±0.91mm, intact = 4.15±0.96 mm, p = 0.014). There was an increased proportion of neovascularity in the residual limb (residual=66.7%, intact=25%; p=0.018). No difference was found in proximal or distal CSA, mid-portion or distal thickness, and PSFR between residual and intact limbs. Conclusions: Patellar tendons in residual limbs of individuals using a PTB prosthesis had greater proximal thickness and mid-portion CSA, as well as a greater proportion of neovascularity than intact limbs. Clinical Relevance: Use of a prosthesis with a PTB feature may cause morphological changes to the patellar tendon. When treating patients with trans-tibial amputations, the health of the patellar tendon may need to be considered.


Trans-Tibial Amputee; Ultrasound Imaging; Patellar Tendon


Medicine and Health Sciences | Physical Therapy | Rehabilitation and Therapy

File Format


File Size

1.212 KB

Degree Grantor

University of Nevada, Las Vegas




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