Suspension Systems for Prostheses

Kapp, Susan

doi:10.1097/00003086-199904000-00008

Cited by 33 publications

(29 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A larger bone indentation area is a factor contributing to better distribution of stresses adjacent to the contact site. 32 Since the current surgical literature recommendations are prone to a more distal amputation level, 43 as for better suspension and control of the prosthesis, 15 the truncated bones could be too sharp, which increases the risk for DTI. A proposed solution to the sharp distal edges of the truncated bones is a surgical technique, named the Ertl technique, which creates a distal tibio-fibular bone bridge that connects the tibia and fibula, and thereby increases the bone-muscle contact region.…”

Section: No Scarmentioning

confidence: 99%

Surgical and Morphological Factors that Affect Internal Mechanical Loads in Soft Tissues of the Transtibial Residuum

et al. 2009

View full text Add to dashboard Cite

The residual limb of transtibial amputation (TTA) prosthetic users is threatened daily by pressure ulcers (PU) and deep tissue injury (DTI) caused mainly by sustained mechanical strains and stresses. Several risk factors dominate the extent of internal tissue loads in the residuum. In this study, we developed a set of three-dimensional finite element (FE) models that were variants of a patient-specific FE model, built from magnetic resonance imaging scans. The set of FE modes was utilized to assess the impact of the following risk factors on the strain/stress distribution in the muscle flap: (i) the tibial length, (ii) the tibial bevelment, (iii) a fibular osteophyte, (iv) the mechanical properties of the muscle, and (v) scarring in different locations and depths. A total of 12 nonlinear FE model configurations, representing variations in these factors, were built and solved. We present herein calculations of compression, tension and shear strains and stresses, von Mises stresses, and strain energy density averaged in critical locations in the muscle flap as well as volumes of concentration of elevated stresses in these areas. Our results overall show higher stresses accumulating in the bone proximity rather than in outlying soft tissues. The longer bone configurations spread the loads toward the external surfaces of the muscle flap. When shortening the truncated bones from 11.2 to 9.2 cm, the von Mises stresses at the distal edges of the bones were relieved considerably (by up to 80%), which indicates a predicted decreased risk for DTI. Decreasing the tibial bevelment mildly, from 52.3 degrees to 37.7 degrees caused propagation of internal stresses from the bone proximity toward the more superficial soft tissues of the residuum, thereby also theoretically reducing the risk for DTI. An osteophyte at the distal fibular end increased the strain and stress distributions directly under the fibula but had little effect (<1%) on stresses at other sites, e.g., under the tibia. Elevation of muscle stiffness (instantaneous shear modulus increase from 8.5 to 16.2 kPa), simulating variation between patients, and muscle flap contraction or spasm, showed the most substantial effect by an acute rise of the von Mises stresses at the bone proximity. The mean von Mises stresses at the bone proximity were approximately twofold higher in the contracted/spastic muscle when compared to the flaccid muscle. Locating a surgical scar in different sites and depths of the residuum had the least influence on the overall loading of the muscle flap (where stresses changed by <7%). Pending further validation by epidemiological PU and DTI risk factor studies, the conclusions of this study can be incorporated as guidelines for TTA surgeons, physical therapists, prosthetists, and the TTA patients themselves to minimize the onset of PU and DTI in this population. Additionally, the present analyses can be used to guide or focus epidemiological research of PU and DTI risk factors in the TTA population.

show abstract

Section: No Scarmentioning

confidence: 99%

Surgical and Morphological Factors that Affect Internal Mechanical Loads in Soft Tissues of the Transtibial Residuum

et al. 2009

View full text Add to dashboard Cite

show abstract

“…1 A proper method of prosthetic suspension ensures a well-functioning and safe prosthesis. 2 Transtibial amputees (TTA) reduce their activity and limit prosthetic use because of residual limb problems and discomfort experienced at the socket interface. 3 In fact, the socket is the critical interface between the stump and the prosthesis.…”

Section: Introductionmentioning

confidence: 99%

A comparison between the suction suspension system and the hypobaric Iceross Seal-In® X5 in transtibial amputees

Brunelli

Delussu

Paradisi

et al. 2013

Prosthetics &Amp; Orthotics International

View full text Add to dashboard Cite

Background: The two passive vacuum suspension systems currently available in total surface-bearing sockets are the hypobaric Iceross Seal-In ® and the suction suspension system. Objectives: The purpose of this study was to compare the effect of the hypobaric Iceross Seal-In ® liner with that of the suction suspension system for quality of life, pistoning, and prosthesis efficiency in unilateral transtibial amputees. Study design: Single-group repeated measures. Methods: Ten amputees were enrolled. The pistoning test, used to compare vertical movement of the stump within the socket, and the energy cost of walking test were carried out when the amputees were wearing the suction suspension system and after 2, 5, and 7 weeks of Seal-In ® X5 use. The Prosthesis Evaluation Questionnaire and the Houghton Scale Questionnaire of perceived mobility and quality of life with the prosthesis, and the Timed Up&Go Test and the Locomotor Capability Index for functional mobility were also administered at the beginning and end of the study. Results: The hypobaric Iceross Seal-In ® X5 led to significant pistoning reduction and improvement on the Houghton Scale Questionnaire and 3 of 9 domains of the Prosthesis Evaluation Questionnaire. No statistical changes were observed in functional mobility or the energy cost of walking tests. Conclusion: Replacing the suction suspension system with the hypobaric Iceross Seal-In ® X5 improves quality of life in transtibial amputees. Clinical relevanceThe main indicator of suspension system efficiency in lower-limb prostheses is pistoning in the socket. Reduced pistoning of the hypobaric Iceross Seal-In ® X5 may contribute to amputees' rehabilitation.

show abstract

“…Prosthetic suspension refers to the mechanism by which the prosthetic socket is secured onto the residual limb of a person with an amputation, with poor suspension resulting in relative motion between the prosthetic socket and residual limb [1]. Vacuum-assisted suspension (VAS) of prosthetic sockets uses electrical or mechanical pumps to create a negative pressure differential, relative to the atmospheric pressure, between the interior of a prosthetic socket and the surface of a liner-clad residual limb.…”

Section: Introductionmentioning

confidence: 99%

Methods for characterization of mechanical and electrical prosthetic vacuum pumps

Komolafe

Wood²,

Caldwell³

et al. 2013

J Rehabil Res Dev

View full text Add to dashboard Cite

Despite increasingly widespread adoption of vacuum-assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm(3) (2 in.(3)) to 197 cm(3) (12 in.(3)) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.

show abstract

Suspension Systems for Prostheses

Cited by 33 publications

References 5 publications

Surgical and Morphological Factors that Affect Internal Mechanical Loads in Soft Tissues of the Transtibial Residuum

Surgical and Morphological Factors that Affect Internal Mechanical Loads in Soft Tissues of the Transtibial Residuum

A comparison between the suction suspension system and the hypobaric Iceross Seal-In® X5 in transtibial amputees

Methods for characterization of mechanical and electrical prosthetic vacuum pumps

Contact Info

Product

Resources

About