Knee Disarticulation Amputation Research Articles

Paediatric Prosthetic Knee Design: The Technical Requirements of a Swing Phase Control Mechanism are Correlated with Parameters of Childhood Growth.

There is a lack of innovation in affordable prosthetic knee joints for children. One significant reason is the absence of technical requirements which consider the foundation of childhood: growth. This study aims to develop and use a modelling tool to determine the technical requirements throughout childhood growth for one prosthetic knee design feature, a swing phase control mechanism (SPCM). 3D gait data of 31 able-bodied children across a range of physical maturities were analyzed. For each participant 2 models were created from a validated paediatric able-bodied musculoskeletal model. The model was first linearly scaled, then a corresponding unilateral right knee-disarticulation amputation model produced by removing segments below the knee and replacing with prosthetic componentry. Long established low-cost prosthetic componentry and a novel polycentric knee were implemented. For each participant, inverse dynamics were conducted and the SPCM torque requirements defined. Prosthetic knee SPCM torque requirements were significantly less than the able-bodied knee to emulate able-bodied gait at free speed: 17.9% (± 10.2) and 66.3% (± 17.0) reduction in maximum extension and flexion torque, respectively. Maximum knee extension torque showed the strongest negative correlation with intact body mass (ρ = -0.6251) whereas flexion torque showed the strongest correlation with height (ρ = 0.6611). Corresponding linear regression fits produced RMSE of 1.91and 1.73 Nm, respectively. Results were also determined for slow and fast speeds. The torque requirements of an affordable paediatric prosthetic knee SPCM are defined and found to strongly correlate with parameters of childhood growth (body mass, height, and age). Current results recommend low-cost paediatric prosthetic SPCM designs can be tailored to accommodate growth. The creation of musculoskeletal models facilitate multiple future studies.

Surgical Technique for Targeted Muscle Reinnervation in Knee Disarticulation Amputation for Nonambulatory Patients.

Chronic neuropathic pain following major limb amputation has historically been difficult to treat. In patients undergoing lower extremity amputation, "preemptive" targeted muscle reinnervation (TMR) nerve transfers may be performed concurrently with the amputation to help mitigate the risk of chronic neuropathic postoperative pain. Despite clinical studies demonstrating efficacy of TMR in lower extremity amputations, few procedural descriptions have been written, and none have been written regarding performing TMR at the knee disarticulation (KD) level of amputation. Although uncommonly utilized, the KD amputation has clear functional benefits over other levels of amputation for nonambulatory patients. As nonambulatory patients are also subject to the occurrence of chronic neuropathic postamputation pain, it stands to reason that the addition of TMR to KD surgery could be an improvement to standard techniques. In this report, we provide a technical description for concurrent TMR with KD and describe the rationale for its use.

Functional Mobility Training with a Powered Knee and Ankle Prosthesis.

Limb loss at the transfemoral or knee disarticulation level results in a significant decrease in mobility. Powered lower limb prostheses have the potential to provide increased functional mobility and return individuals to activities of daily living that are limited due to their amputation. Providing power at the knee and/or ankle, new and innovative training is required for the amputee and the clinician to understand the capabilities of these advanced devices. This protocol for functional mobility training with a powered knee and ankle prosthesis was developed while training 30 participants with a unilateral transfemoral or knee disarticulation amputation at a nationally ranked physical medicine and rehabilitation research hospital. Participants received instruction for level-ground walking, stair climbing, incline walking, and sit-to-stand transitions. A therapist provided specific training for each mode including verbal, visual, and tactile cueing along with patient education on the functionality of the device. The primary outcome measure was the ability of each participant to demonstrate independence with walking and sit-to-stand transitions along with modified independence for stair climbing and incline walking due to the use of a handrail. Every individual was successful in comfortable ambulation of level-ground walking and 27 out of 30 were successful in all other functional modes after participating in 1–3 sessions of 1–2 h in length (3 terminated their participation before attempting all activities). As these prosthetic devices continue to advance, therapy techniques must advance as well, and this paper serves as education on new training techniques that can provide amputees with the best possible tools to take advantage of these powered devices to achieve their desired clinical outcomes.

Stability and Falls Evaluations in AMPutees (SAFE-AMP 1): Microprocessor knee technology reduces odds of incurring an injurious fall for individuals with diabetic/dysvascular amputation

ABSTRACT Individuals with lower limb amputation have a high incidence of falls. Above-the-knee amputation and diabetes/vascular disease are both risk factors for falls. Microprocessor knee (MPK) technology may reduce falls in this population. The objective was to determine the association between MPKs and reduced injurious falls. A retrospective analysis of injurious falls within a large, national outcomes database was conducted. Inclusion was limited to adult K3 ambulators with unilateral, transfemoral, or knee disarticulation amputation due to diabetes/vascular disease. There were 744 out of 881 individuals that did not receive an MPK. Results showed that 16.3% of non-MPK users experienced an injurious fall compared to 7.3% of MPK users (p = .007). Not having an MPK resulted in significantly increased odds (unadjusted: OR: 2.47, 95% CI: 1.26–4.83, p = .009; adjusted for confounders: OR: 2.52, 95% CI: 1.28–4.94, p = .007) of incurring an injurious fall over a 6-month period. In conclusion, the current study found use of an MPK strongly associated with reduced injurious falls in a population of patients with amputation due to diabetes/vascular disease. The findings strongly support the use of MPK technology to mitigate fall risk, and in particular injurious falls requiring medical intervention.

Use of foot fillet flap for knee disarticulation in children with tibial hemimelia

Tibial hemimelia is a rare disease characterized by the absence or hypoplasia of the tibia. Because of the difficulties of reconstruction due to joint involvement in more severe cases, knee disarticulation and above-knee amputations are a treatment option. We report the case of a patient treated with knee disarticulation amputation and pedicled foot fillet flap. Level of Evidence V; Therapeutic Studies; Expert Opinion.

Reduced cortical brain activity with the use of microprocessor-controlled prosthetic knees during walking.

Individuals using a lower-limb prosthesis indicate that they need to concentrate on every step they take. Despite self-reports of increased cognitive demand, there is limited understanding of the link between cognitive processes and walking when using a lower-limb prosthesis. The objective was to assess cortical brain activity during level walking in individuals using different prosthetic knee components and compare them to healthy controls. It was hypothesized that the least activity would be observed in the healthy control group, followed by individuals using a microprocessor-controlled prosthetic knee and finally individuals using a non-microprocessor-controlled prosthetic knee. Cross-sectional study. An optical brain imaging system was used to measure relative changes in concentration of oxygenated and de-oxygenated haemoglobin in the frontal and motor cortices during level walking. The number of steps and time to walk 10 m was also recorded. The 6-min walk test was assessed as a measure of functional capacity. Individuals with a transfemoral or knee-disarticulation amputation, using non-microprocessor-controlled prosthetic knee ( n = 14) or microprocessor-controlled prosthetic knee ( n = 15) joints and healthy controls ( n = 16) participated in the study. A significant increase was observed in cortical brain activity of individuals walking with a non-microprocessor-controlled prosthetic knee when compared to healthy controls ( p < 0.05) and individuals walking with an microprocessor-controlled prosthetic knee joint ( p < 0.05). Individuals walking with a non-microprocessor-controlled prosthetic knee demonstrated an increase in cortical brain activity compared to healthy individuals. Use of a microprocessor-controlled prosthetic knee was associated with less cortical brain activity than use of a non-microprocessor-controlled prosthetic knee. Increased understanding of cognitive processes underlying walking when using different types of prosthetic knees can help to optimize selection of prosthetic components and provide an opportunity to enhance functioning with a prosthesis.

Distance et vitesse de marche chez les amputés en transfémoral équipés d’une prothèse à appui distal

IntroductionPreservation of femoral condyles in patients with knee disarticulation amputation (KDA) facilitates distal support inside the socket, compared to transfemoral amputation (TFA), and allows the direct transfer of weight-bearing loads toward residual limbs. HypothesisThe hypothesis was that the gait distance and speed of TFA patients after a surgical femoral implant that allowed the distal support of the residuum would improve. Material and methodsIn total, 23 TFA patients received a titanium implant that allowed the distal weight bearing of the residuum inside the socket. The post-intervention follow-up period lasted 14 months. Gait distance and speed were assessed with the 2-minute walk test (2MWT). ResultsThe amputation etiology was trauma in 11 patients (48%), peripheral vascular disease in nine (39%) and oncologic disease in three (13%). The mean 2MWT distance was 103.6±34.7m prior to femoral implant and 128±38.9m at 14 months, which implies an improvement of 24% (p<0.001). The mean gait speed was 0.86±0.29m/s prior to femoral implant and 1.06±0.32m/s at 14 months (p<0.001). DiscussionAfter implant placement, distance covered increased by 24%. This value is higher than those described by other groups, such as Rau (12.6%) and Darter (19.2%), who assessed improvement in distance covered with the 2MWT in a younger population and after completing different physiotherapy programs. Our results showed improved distance walked and gait speed as well as in the physical functioning score in TFA patients 14 months after receiving a femoral implant that permitted distal residuum loading. Type of studyAn experimental prospective study. Level of proofIII, case-control study.

The risk of major cardiovascular events for adults with transfemoral amputation

BackgroundIt is well-known that the risk of cardiac disease is increased for those with lower-limb amputations, likely as a result of the etiology of the amputation. Using a longitudinal population-based dataset, we examined the association between transfemoral amputation (TFA) status and the risk of experiencing a major cardiac event for those undergoing either dysvascular or traumatic amputations. The association of receiving a prosthesis with the risk of experiencing a major cardiac event was also examined.MethodsStudy Population: All individuals with TFA (N 162), i.e. knee disarticulation and transfemoral amputation, residing in Olmsted County, MN, between 1987 and 2014. Each was matched (1:10 ratio) with non-TFA adults on age, sex, and duration of residency.Data Analysis: A competing risk Cox proportional hazard model was used to estimate the relative likelihood of an individual with a TFA experiencing a major cardiac event in a given time period as compared to the matched controls. The cohort was divided by amputation etiology: dysvascular vs trauma/cancer. Additional analysis was performed by combining all individuals with a TFA to look at the relationship between prosthesis receipt and major cardiac events.ResultsIndividuals with a dysvascular TFA had an approximately four-fold increased risk of a cardiac event after undergoing an amputation (HR 3.78, 95%CI: 3.07–4.49). These individuals also had an increased risk for non-cardiac mortality (HR 6.27, 95%CI: 6.11–6.58). The risk of a cardiac event was no higher for those with a trauma/cancer TFA relative to the able-bodied controls (HR 1.30, 95%CI: 0.30–5.85). Finally, there was no difference in risk of experiencing a cardiac event for those with or without prosthesis (HR 1.20, 95%CI: 0.55–2.62).ConclusionThe high risk of initial mortality stemming from an amputation event may preclude many amputees from cardiovascular disease progression. Amputation etiology is also an important factor: cardiac events appear to be more likely among patients with a dysvascular TFA. Providing a prosthesis does not appear to be associated with a reduced risk of a major cardiac event following amputation.

Distance and speed of walking in individuals with trans-femoral amputation fitted with a distal weight-bearing implant.

Preservation of femoral condyles in patients with knee disarticulation amputation (KDA) facilitates distal support inside the socket, compared to trans-femoral amputation (TFA), and allows the direct transfer of weight-bearing loads toward residual limbs. The hypothesis was that the gait distance and speed of TFA patients after a surgical femoral implant that allowed the distal support of the residuum would improve. Twenty-three TFA patients received a titanium implant that allowed the distal weight bearing of the residuum inside the socket. The post-intervention follow-up period lasted 14 months. Gait distance and speed were assessed with the 2-minute walk test (2MWT). The amputation etiology was trauma in 11 patients (48%), peripheral vascular disease in nine (39%) and oncologic disease in three (13%). The mean 2MWT distance was 103.6±34.7m prior to femoral implant and 128±38.9m at 14 months, which implies an improvement of 24% (p<0.001). The mean gait speed was 0.86±0.29m/s prior to femoral implant and 1.06±0.32m/s at 14 months (p<0.001). After implant placement, distance covered increased by 24%. This value is higher than those described by other groups, such as Rau (12.6%) and Darter (19.2%), who assessed improvement in distance covered with the 2MWT in a younger population and after completing different physiotherapy programs. Our results showed improved distance walked and gait speed as well as in the physical functioning score in TFA patients 14 months after receiving a femoral implant that permitted distal residuum loading. An experimental prospective study. III, case-control study.

Functional Outcomes of Service Members With Bilateral Transfemoral and Knee Disarticulation Amputations Resulting From Trauma.

As longitudinal studies for those with bilateral transfemoral amputation (BTFA) or knee disarticulation (KD) are lacking, it is important to quantify performance measures during rehabilitation in an effort to determine reasonable expectations and trends that may influence the rehabilitation process. At initial evaluation (date of first independent ambulation) and follow up (median 135 [range = 47-300] days later), 10 participants with BTFA/KD completed 6 minute walk testing and Activity Specific Balance Confidence and Lower Extremity Functional Scale questionnaires. Of these, six participants also completed stair ambulation; ascent time and stair assessment index (SAI) scores were calculated. Patients utilized their prescribed prostheses at each visit. Participants were able to cover a significantly greater distance (135.3 [70.1] m) in 6 minutes at the follow-up visit (*p = 0.005). The change in SAI scores for stair ascent and descent was not statistically significant (p = 0.247). Stair ambulation confidence scores were significantly greater at the final visit (*p = 0.034). Stair negotiation appears to plateau early; however, confidence builds despite absence of functional gains over time. Service members with BTFAs/KDs are able to achieve functional community ambulation skills. Thus, this investigation suggests that clinicians can realign rehabilitation paradigms to shift focus towards community distance ambulation once safe stair ascent and descent is achieved.

Intuitive control of a powered prosthetic leg during ambulation: a randomized clinical trial.

Some patients with lower leg amputations may be candidates for motorized prosthetic limbs. Optimal control of such devices requires accurate classification of the patient's ambulation mode (eg, on level ground or ascending stairs) and natural transitions between different ambulation modes. To determine the effect of including electromyographic (EMG) data and historical information from prior gait strides in a real-time control system for a powered prosthetic leg capable of level-ground walking, stair ascent and descent, ramp ascent and descent, and natural transitions between these ambulation modes. Blinded, randomized crossover clinical trial conducted between August 2012 and November 2013 in a research laboratory at the Rehabilitation Institute of Chicago. Participants were 7 patients with unilateral above-knee (n = 6) or knee-disarticulation (n = 1) amputations. All patients were capable of ambulation within their home and community using a passive prosthesis (ie, one that does not provide external power). Electrodes were placed over 9 residual limb muscles and EMG signals were recorded as patients ambulated and completed 20 circuit trials involving level-ground walking, ramp ascent and descent, and stair ascent and descent. Data were acquired simultaneously from 13 mechanical sensors embedded on the prosthesis. Two real-time pattern recognition algorithms, using either (1) mechanical sensor data alone or (2) mechanical sensor data in combination with EMG data and historical information from earlier in the gait cycle, were evaluated. The order in which patients used each configuration was randomized (1:1 blocked randomization) and double-blinded so patients and experimenters did not know which control configuration was being used. The main outcome of the study was classification error for each real-time control system. Classification error is defined as the percentage of steps incorrectly predicted by the control system. Including EMG signals and historical information in the real-time control system resulted in significantly lower classification error (mean, 7.9% [95% CI, 6.1%-9.7%]) across a mean of 683 steps (range, 640-756 steps) compared with using mechanical sensor data only (mean, 14.1% [95% CI, 9.3%-18.9%]) across a mean of 692 steps (range, 631-775 steps), with a mean difference between groups of 6.2% (95% CI, 2.7%-9.7%] (P = .01). In this study of 7 patients with lower limb amputations, inclusion of EMG signals and temporal gait information reduced classification error across ambulation modes and during transitions between ambulation modes. These preliminary findings, if confirmed, have the potential to improve the control of powered leg prostheses.

Compensatory-step training of healthy, mobile people with unilateral, transfemoral or knee disarticulation amputations: A potential intervention for trip-related falls

The purpose of this study was to evaluate the effects of compensatory-step training of healthy, mobile, young-to-middle aged people with unilateral, transfemoral or knee disarticulation amputations. Outcomes of interest included recovery success, reliance on the prosthesis, and the kinematic variables relevant to trip recovery. Over the course of six training sessions, five subjects responded to postural disturbances that necessitated forward compensatory steps to avoid falling. Subjects improved their ability to recover from these postural disturbances without falling or hopping on the non-prosthetic limb. Subjects improved their compensatory stepping response by decreasing trunk flexion and increasing the sagittal plane distance between the body center of mass and the stepping foot. In response to more challenging disturbances, these training-related improvements were not observed for the initial step with the non-prosthetic limb. Regardless of the stepping limb, step length and the change in pelvic height were not responsive to training. This study exhibits the potential benefits of a compensatory-step training program for amputees and informs future improvements to the protocol.

Trip recoveries of people with unilateral, transfemoral or knee disarticulation amputations: Initial findings

The purpose of this report is to provide novel findings from the kinematics of five amputees following a laboratory-induced trip. Only amputees with a unilateral, transfemoral or knee disarticulation amputation were included in this study. When the prosthesis was obstructed, all subjects used a lowering strategy, resulting in three harness-assisted recoveries and one fall. When the non-prosthetic limb was obstructed, one subject fell using an elevating strategy, one subject fell using a lowering strategy, and one subject, who was harness-assisted, used a hopping strategy. These results can be used to guide further studies of how to limit prosthetic knee flexion due to weight-bearing during a lowering strategy, implement compensatory step training to reduce fall risk, and identify appropriate, context-specific recovery strategies for people with transfemoral or knee disarticulation amputations.

Subcutaneous Internal-External Fixation for Pelvic Fracture Fixation: A Novel Approach for Open Fracture Fixation: A Case Report.

Pelvic fractures account for 1.5% to 3% of all fractures1,2. A majority of these fractures are from low-energy mechanisms, such as a fall from standing height in elderly, osteoporotic patients. In younger patients, pelvic fractures are often the result of high-energy trauma. Of all pelvic fractures, 0.1% to 4% are open fractures1-5. Up to 72% of these represent a Gustilo-Anderson Type-III fracture caused by the large amount of force needed to penetrate the soft-tissue envelope around the pelvis6. Open fractures of the pelvic ring have been described as occurring in one of three zones: zone I, which encompasses the perineum; zone II, which encompasses the medial thigh or groin; or zone III, which encompasses the posterolateral buttock2. Open fractures associated with perineal injuries are associated with a higher mortality given the extent of injury and risk for infection. Closed fractures have a substantially lower mortality rate of 10.5%, compared with a mortality rate of up to 50% with open fractures3. The higher rate of mortality is caused by hemorrhage, associated injuries, and sepsis2,4. We present a patient with an anteroposterior compression type-II (APC-II) pelvic fracture with substantial gluteal/perineal wounds, who was treated with an anterior subcutaneous external fixator facilitating prone positioning during multiple surgical debridements. The patient was informed that data concerning the case would be submitted for publication, and he provided consent. A twenty-seven-year-old man was injured in overseas combat by an improvised explosive device. He sustained ruptured tympanic membranes; a traumatic right knee disarticulation and left transfemoral amputation; an open zone I, APC-II pelvic fracture; an open coccygeal fracture; a complex gluteal/perineal wound; and scrotal injuries. Prior to arrival at our facility, he underwent debridement of the wounds with an …

Pain and pain-related interference in adults with lower-limb amputation: Comparison of knee-disarticulation, transtibial, and transfemoral surgical sites

Pain and pain-related interference with physical function have not been thoroughly studied in individuals who have undergone knee-disarticulation amputations. The principal aim of this study was to determine whether individuals with knee-disarticulation amputations have worse pain and pain-related interference with physical function than do individuals with transtibial or transfemoral amputations. We analyzed cross-sectional survey data provided by 42 adults with lower-limb amputations. These individuals consisted of 14 adults reporting knee-disarticulation amputation in one limb and best-matched cases (14 reporting transfemoral amputation and 14 reporting transtibial amputation) from a larger cross-sectional sample of 472 individuals. Participants were rigorously matched based on time since amputation, reason for amputation, age, sex, diabetes diagnosis, and pain before amputation. Continuous outcome variables were analyzed by one-way analysis of variance. Categorical outcomes were analyzed by Pearson chi-square statistic. Given the relatively small sample size and power concerns, mean differences were also described by estimated effect size (Cohen's d). Of the 42 participants, 83% were male. They ranged in age from 36 to 85 (median = 55.1, standard deviation = 11.0). Most amputations were of traumatic origin (74%), and participants were on average 12.4 years from their amputations at the time of the survey. Individuals with transtibial amputation reported significantly more prosthesis use than did individuals with knee-disarticulation amputation. Amputation levels did not significantly differ in phantom limb pain, residual limb pain, back pain, and pain-related interference with physical function. Estimates of effect size, however, indicated that participants with knee-disarticulation amputation reported less phantom limb pain, phantom limb pain-related interference with physical function, residual limb pain, residual limb pain-related interference with physical function, and back pain-related interference with physical function than did participants with transtibial or transfemoral amputations. This study demonstrated that patients with knee-disarticulation amputation used prostheses significantly less than did patients with transtibial amputation. However, no evidence was found that patients with knee-disarticulation amputation have worse outcomes in terms of pain and pain-related interference with physical function; in fact, they may have more favorable long-term outcomes.

Comparison Between the C-leg® Microprocessor-Controlled Prosthetic Knee and Non-Microprocessor Control Prosthetic Knees

This study investigated energy expenditure and obstacle course negotiation between the C-leg and various non-microprocessor control (NMC) prosthetic knees and compared a quality of life survey (SF-36v2) of use of the C-leg to national norms. Thirteen subjects with unilateral limb loss (12 with trans-femoral and one with a knee disarticulation amputation) participated in the study. The mean age was 46 years, range 30-75. Energy expenditure using both the NMC and C-leg prostheses was measured at self-selected typical and fast walking paces on a motorized treadmill. Subjects were also asked to walk through a standardized walking obstacle course carrying a 4.5 kg (10 lb) basket and with hands free. Finally, the SF-36v2 was completed for subjects while using the C-leg. Statistically significant differences were found in oxygen consumption between prostheses at both typical and fast paces with the C-leg showing decreased values. Use of the C-leg resulted in a statistically significant decrease in the number of steps and time to complete the obstacle course. Scores on a quality of life index for subjects using the C-leg were above the mean for norms for limitation in the use of an arm or leg, equal to the mean for the general United States population for the physical component score and were above this mean for the mental component score. Based on oxygen consumption and obstacle course findings, the C-leg when compared to the NMC prostheses may provide increased functional mobility and ease of performance in the home and community environment. Questionnaire results suggest a minimal quality of life impairment when using a C-leg for this cohort of individuals with amputation.

Influence of Rotators on the Kinematic Adaptations in Stubby Prosthetic Gait

We report on the results of gait analysis in a patient with bilateral knee disarticulation amputations who used short nonarticulated prosthetic limbs (stubbies) to meet his ambulation needs over an extended period. To compensate for the loss of knee and ankle articulations, exaggerated pelvic obliquity (hip hiking), transverse pelvic rotation, and hip abduction were needed to ensure limb clearance and a functional step length. The addition of rotators to the prostheses improved gait velocity and reduced the perceived exertion of walking by favorably altering center of mass energetics.

Amputation of the lower limb as palliative treatment for debilitating musculoskeletal cancer

Limb sparing surgery has replaced amputation surgery for treating sarcomas of the lower limb in most cases. Wide resection followed by postoperative radiation therapy can achieve acceptable local control and survival rates in patients with bone and soft-tissue sarcomas of the lower limb. Recurrent or persistent disease constitutes a major oncological problem. Local symptoms such as agonizing pain, fractures, tumor fungation, inability to walk and inability to maintain daily activities, further impair the patient's quality of life. In this clinical set-up palliative amputation of the limb should be considered. Fourteen patients with soft-tissue or bone sarcomas underwent palliative major amputation. The procedures included: hemipelvectomy, hip disarticulation, knee disarticulation, above or below-knee amputation. Local control of the disease and pain, and improvement of the performance status were observed in 13 evaluable patients. The mobility was restored in 13/14 patients. The median survival following the procedure was 9 months. There was only one case of immediate post-operative death. Severe phantom pain was not reported by any of the patients. Quality of life was reported to be improved by two-thirds of the patients. We found palliative major amputation surgery worth-performing in low-performance status cancer patients with locally advanced disease of the lower limb.

Functional outcome of rehabilitated bilateral lower limb amputees.

The functional outcome of rehabilitated bilateral lower limb amputees was studied. The study included 31 amputees who were admitted during 1980-1990 to a rehabilitation centre in the north of the Netherlands. The clinical notes made during the patients' admission were studied to obtain information about their characteristics, while mobility and prosthetic use were studied at discharge. The patients who were alive and willing to participate in the study were interviewed by a physician at their residence in November 1992, using among other things, the Sickness Impact Profile (SIP) and the Life Satisfaction questionnaire. Some 25 of the 31 patients were amputated for vascular reasons, 1 patient primarily for traumatic reasons and secondarily for vascular reasons, 5 patients for traumatic reasons. Eight patients had a bilateral trans-femoral amputation, 18 patients a bilateral trans-tibial amputation, 2 patients a combination of trans-tibial and knee-disarticulation amputation, 3 patients a trans-femoral/trans-tibial amputation. Mean age at second amputation was 66.3 years. Of the 31 amputees 21 were men and 10 women, 25 amputees were prosthetically rehabilitated during admission, 3 of them died during admission and 5 did not achieve mobility at discharge. In their activities of daily life 22 of the 28 patients alive at discharge were almost independent. At the time of the follow-up evaluation 17 of the 31 patients had died. For several reasons only 8 patients could be included in the follow-up, 6 vascular amputees and 2 traumatic amputees.(ABSTRACT TRUNCATED AT 250 WORDS)

The Influence of Early Weight-bearing on Experimental Total Hip Arthroplasties in Dogs

The bone-cement interface is an area of concern in the long-term fixation of endoprostheses. The effect of early weight-bearing on the interface has been discussed as an important parameter influencing the characteristics of the interface. In this study, a total hip arthroplasty was performed in two groups of six dogs each. One group was allowed immediate weight-bearing, while in the other, a knee disarticulation amputation was done to prevent weight-bearing. Three animals of each group were killed at three months and three of each group at six months, and a histological study of the interface was done. No morphologic difference was observed between weight-bearing and nonweight-bearing animals in the interface area. Endosteal bone remodeling occurred regardless of weight-bearing stresses. A fibrous membrane was found between the cement and the endosteal surface of the femur, and membrane thickness was similar in all animals. The membrane between the cement and acetabular bone, however, was consistently thicker. Quantitative studies revealed increased femoral cortical bone resorption in the nonweight-bearing animals.