Technical note: Hanging stump prosthesis without socket for bad above-knee stumps
N. Chand *
R. K. Srivastava *
A. R. Maish *
This prosthesis was developed in the Department of Rehabilitation, Safdarjang Hospital, New Delhi, India to deal with the problems of badly formed or difficult above-knee stumps. Bad stumps are still a challenge for the rehabilitation team due to the difficulty in fitting the prosthesis which is the first stage in the total rehabilitation of the amputee. It is the author's observation that those cases with bad above-knee stumps who are fitted with a prosthesis with some type of socket keep attending the prosthetic section complaining of pain. The pain in most of these cases is due to local contact of the stump surface with the socket. None of the prostheses already available can deal with this problem effectively. The hanging stump prosthesis without socket has been developed on the principle of no socket, no contact, no pain. This prosthesis has no socket but a metallic ring consisting of a well padded, well moulded ischial seat. This metallic ring is attached to the hollowed out wooden thigh piece by medial and lateral vertical bars. The outer side of the metallic ring is attached to the pelvic belt through the hip joint. The rest of the prosthesis is similar to the standard above-knee prosthesis.
Description of prosthesis
The main feature of this prosthesis is one metallic ring and no socket. The metallic ring consists of four bars, anterior, posterior, medial and lateral. The anterior and lateral bars are at a higher level than the medial and posterior bars. The anterior bar is obliquely placed, its lateral end being higher than the medial and becoming continuous with the medial bar. The shape of this ring is somewhat similar to the upper end of a quadrilateral socket. The lateral bar is connected with a pelvic belt through a uniaxial hip joint permitting only flexion and extension. The metallic ring is well moulded and well padded, especially the posterior bar which forms the ischial seat. The medial and lateral bars of the ring are attached to two vertical bars; the lower end of the vertical bars are attached to the thigh piece. The wooden thigh piece is hollowed out to make the prosthesis light. The upper end of the thigh piece is covered with padding. Knee lock is provided on the anterior aspect. The remaining parts of this prosthesis (Fig. 1) are similar to a standard above-knee prosthesis.
Review of literature
Little work has been carried out on this subject so far. Only a few prostheses are available which deal mainly with the problem of short stumps and their role in cases of various other types of difficult stumps is relatively unexplored.
Habermann (United States Army, 1946) constructed a special prosthesis for very short above-knee stumps with limited or negligible range of motion at the hip joint. It has a socket pivoted to the remaining thigh piece, generally with a lock for walking which can be released for sitting. The movement takes place between socket and thigh piece. The principle of suction socket has been used in this prosthesis.
A "saucer type" socket prosthesis (Catranis Incorporated, 1954) has also been developed for very short, flexed above-knee stumps which are almost hip disarticulation level. This is suited to the rounded contour of the stump which fits into the shallow socket while standing and yet allows the socket to slide neatly around the stump. The patient sits with the stump directly on a chair without any intervening socket. The prosthesis also has a pelvic belt with a hip joint with lock, which is usually kept locked during walking using abdominal and back muscles.
The conventional "tilting table" type of prosthesis normally used for hip disarticulation (Murphy, 1952) has also been recommended for very short above-knee stumps. It has a reinforced moulded leather socket with a broad pelvic band. The hip joint is usually kept locked between the thigh portion and the leather socket. The mechanical hip joint has to be strong enough to withstand repeated applications of bending moments during locomotion. A metal track is therefore attached in the vertical plane. This track frequently damages clothing. It also tends to raise the amputated side from the chair, which may be desirable in cases of hemipelvectomy but is most objectionable in the short above-knee amputee.
Ambulation is the first stage towards the rehabilitation of an amputee. Bad stumps are still a challenge for the rehabilitation team, but enough attention has not been paid to this problem which is more serious in the case of above-knee amputees who are not ready to sacrifice even an inch of their remaining stump. So they are made ambulatory either in a wheelchair or keep on walking with crutches or with some sort of socket prosthesis fitted to them. The use of a wheelchair or crutches in these cases directly reflects on some fault in our rehabilitation programme. Those amputees who are fitted with some type of prosthesis incorporating a socket keep on attending the prosthetic section with the complaint of pain. Due to the day to day problem of pain they ultimately reject the prosthesis. None of the available prostheses are able to deal with this problem. This prosthesis was developed on the principle of no socket, no contact, no pain, because the pain in most of these amputees with bad stumps is due to the local contact of the stump surface with the socket surface. If there is no contact, there should be no pain. Of all available prostheses, the suction socket prosthesis only deals with the problems of short stump, phantom pain and restricted mobility of the proximal joint while the saucer socket prosthesis and tilting table prosthesis can also be used in the case of flabby stump musculature in addition to the problems already dealt with by the suction socket prosthesis. The saucer socket prosthesis has also been used for cases with flexion contracture of the hip joints. None of these solutions deal with the other problems such as extremely tapered stumps, infected stumps, stumps with unhealthy and excessive or weak scars, bony spurs, neuroma and problem of allergy of stump surface to the socket finish etc. The hanging stump prosthesis without socket deals with these problems and can also be given in case of flabby musculature and flexion contracture. The stump hangs in the prosthesis (Fig. 2) while the patient is in the standing position or walking, and the weight is borne on a well padded, well moulded ischial seat. The patient can walk with the hip joint open and can sit comfortably. He feels very secure because of the pelvic belt. The assembly of the prosthesis is easy and cosmetically it is well accepted.
We are grateful to Dr. B. P. Yadav, Consultant and Head of the Department of Rehabilitation, Safdarjang Hospital, New Delhi, for the inspiration and guidance provided by him to carry out this work. Our appreciation and thanks are due to Dr. U. Singh for the photographic work and his help in checking the manuscript.
- Catranis Incorporated (1954). Improved artificial limbs for lower extremity amputations; subcontractors final report to the Advisory Committee on Artificial Limbs, National Research Council-Syracuse, NY: Catranis.
- Murphy, E. F. (1952). Lower extremity components. In: American Academy of Orthopedic Surgeons. Orthopedic appliances atlas-Ann Arbor, MI: J. W. Edwards, 228-230.
- United States Army (1946). Office of the Surgeon General, Commission on Amputations and Prostheses. Report of European observations- Washington: Office of the Surgeon General, 66-77, 127.