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At least 19 recordsLinked to original sources
PubMed1990

Knee motion in total knee arthroplasty. A roentgen stereophotogrammetric analysis of the kinematics of the Tricon-M knee prosthesis.

The three-dimensional kinematics of the Tricon-M knee prosthesis during active knee flexion and extension were recorded in 11 patients with arthrosis or rheumatoid arthritis using roentgen stereophotogrammetric analysis. Twenty-three normal knees constituted the control group. The prosthetic knees displayed the same degrees of freedom regarding rotational and translational movements as the normal knees, although the kinematics were different. A combination of internal rotation, abduction, and lateral translation of the tibia was recorded during flexion, and the reversed movements were recorded during extension. During the first 25 degrees of flexion, these movements were small, reflecting the high congruency between the articular surfaces, while beyond 25 degrees they increased. The normal knees displayed a combination of internal rotation, adduction, and medial translation of the tibia during flexion and the reversed movements during extension. The prosthetic knees also exhibited an increased posterior displacement during increasing flexion when compared with the normal knees. There was a correlation between the positioning of the femoral component in the sagittal plane and the recorded anterior/posterior translations. In conclusion, the kinematics of the Tricon-M knee prosthesis significantly differ from the normal knee, probably because of the design of the prosthesis and the absence of the cruciate ligaments.

Aged↗
PubMed1992

Function after through-knee compared with below-knee and above-knee amputation.

Fifty-nine amputees, 24 below-knee (BK), 17 through-knee (TK) and 18 above-knee (AK) who had prosthetic replacements, were evaluated using a questionnaire which provided a quantitative and qualitative assessment scale for the prosthetic function. The ability to apply or don the prosthesis was noted in 100% of the BK, 70% of the TK and 56% of the AK amputations (p < 0.001). Daily use of the prosthesis was recorded in 96% of the BK, 76% of the TK and 50% of the AK amputations (p < 0.001). A higher level of amputation resulted in a significantly lower degree of rehabilitation (p < 0.05). The qualitative evaluation shows that the higher the level of amputation, the lower the usefulness of the prosthesis. Four percent of the BK, 12% of the TK and 39% of the AK amputees had no use whatsoever of their prosthesis (p < 0.01). From a functional standpoint, TK amputation should always be considered as the primary alternative to AK amputation when a BK amputation is not feasible.

Aged↗
PubMed1991

Total knee arthroplasty in valgus knees.

One hundred thirty-four total knee arthroplasties in 98 patients with a valgus alignment were analyzed. Knees with a preoperative alignment of 10 degrees or greater anatomic valgus were believed suitable for inclusion. The average follow-up period in these patients was 4.5 years (range, two to ten years). One hundred eighteen knees were implanted with a posterior stabilized prosthesis, eight knees with a constrained implant design, four knees with a total condylar prosthesis, and four knees with a cruciate-retaining design. All components in all knees were cemented. A lateral retinacular release was necessary in 76% of the arthroplasties secondary to intraoperative lateral subluxation of the patella. The ligamentous release for balancing these valgus-deformed knees was done from the femur. There were 95 knees (71%) rated as excellent, 27 knees (20%) as good, eight knees (6%) as fair, and four knees (3%) as poor. Postoperatively, 76% of the knees had a tibiofemoral alignment between 5 degrees and 9 degrees valgus with an overall average of 7 degrees valgus (range, 3 degrees varus to 15 degrees valgus). Total knee arthroplasty is a reliable and durable procedure in the treatment of valgus knee arthritis. However, valgus-deformed knees represent a greater challenge than their varus counterparts to the implant surgeon in terms of the intraoperative balancing required. This may be a function of the greater difficulty in achieving ligamentous equilibrium and the relative rarity of valgus-deformed knees.

Adult↗
PubMed1990

Conditions of isokinetic knee flexion that enhance isokinetic knee extension.

The results of two experiments are reported. The purpose of the initial investigation was to determine the effect of isokinetic knee flexion contraction intensity on subsequent knee extension contraction. Seven subjects performed ten isokinetic knee flexion-extension cycles at six isokinetic velocities under two antagonist contraction conditions. In the first condition, isokinetic knee flexion and extension were speed-matched, and, in the second condition, the high-speed condition, knee flexion was 7.85 rad.s-1 irrespective of knee extension velocity, which ranged from 0.52 to 7.85 rad.s-1. Significantly greater isokinetic knee extension measures were observed at low isokinetic velocities and were associated with the high-speed contraction condition. Enhancement of the knee extension contraction was in the initial work phase of the isokinetic contraction. The second experiment was conducted to determine whether the enhancement of the initial work phase could be associated, in part, with passive elastic qualities of the involved musculature. In this study the range of motion for the knee involved musculature. In this study the range of motion for the knee extension-flexion cycles was reduced from the previous 2.01 rad to 1.57 rad. Two isokinetic knee extension velocities were studied (1.57 and 7.85 rad.s-1) under five conditions: initiated from rest, initiated from isometric knee flexion MVC, and with preceding isokinetic knee flexion at 0.52, 4.19, and 7.85 rad.s-1. The hypothesis that knee extension contraction measures would not increase was supported. Based upon the results of the two experiments, it is suggested that the increases in knee extension contraction measures observed in the first experiment are at least partially mediated by the contribution to net torque by passive elastic musculotendinous elements. Further study of this phenomenon with the inclusion of electromyographic measures will allow determination of the presence and contribution of increased neural drive.

Adult↗
PubMed1989

Rehabilitation after lower limb amputation: a comparative study of above-knee, through-knee and Gritti-Stokes amputations.

A study of 169 unilateral amputees under three Disablement Services Centres was performed. The study comprised 88 above-knee, 54 through-knee and 27 Gritti-Stokes amputations. Satisfactory rehabilitation occurred in 33 per cent of above-knee, 62 per cent of through-knee and 44 per cent of Gritti-Stokes patients (56 per cent overall). The better rehabilitation of through-knee versus above-knee amputees (P less than 0.02) was also found in a group of patients matched for comparable age and duration of amputation as well as in a group of age-matched vascular amputees. Through-knee amputees relied significantly less on wheelchairs than above-knee (P = 0.016) and Gritti-Stokes (P = 0.05) amputees. The prosthesis used for the through-knee and Gritti-Stokes amputations was considered unsightly in 50 per cent of cases (versus 31 per cent for the above-knee prosthesis). The superior rehabilitation with through-knee amputations should prompt us to improve both our technique for this amputation and the prostheses currently available. A through-knee amputation should be performed in preference to an above-knee amputation in the case where either is surgically possible, and a below-knee amputation not feasible.

Adult↗
PubMed1979

Foot-pounds of torque of the normal knee and the rehabilitated postmeniscectomy knee.

Foot-pounds of torque of the knee flexors and knee extensors of eight rehabilitated patients who had had meniscectomies were obtained isometrically and at 60 and 210 degrees per second by use of an isokinetic apparatus. Our purpose was to test the null hypothesis that no significant difference in torque would be manifested between the rehabilitated postmeniscectomy knee and the normal knee. Mean torque developed by the rehabilitated postoperative knee was 10 to 12 percent less than the mean torque developed by the normal knee. We found a significant difference between means of torque of the normal knee and the rehabilitated knee for isometric flexion, rapid dynamic flexion, and rapid dynamic extension. Means of torque of knee extension for the three types of contraction for both knees of the subjects demonstrated similar patterns in which torque developed isometrically was greater than torque developed by slow dynamic tension, which in turn was greater than torque developed by rapid dynamic contraction. Means of torque of knee flexion for the three types of contraction for both knees of the subjects created patterns in which torque developed isometrically was essentially equal to torque developed by slow dynamic tension, and both these measurements exceeded torque developed by rapid dynamic contractions. Overall, the results suggest that physical therapists need to use rehabilitative techniques that promote muscular power and muscular endurance in addition to muscular strength and that more attention needs to be directed to the rehabilitation of knee flexors.

Adolescent↗
PubMed1989

The association of knee injury and obesity with unilateral and bilateral osteoarthritis of the knee.

The strength of the associations of knee injury and obesity with osteoarthritis of the knee was studied for 3,885 adults aged 45-74 years who received knee x-rays in the First National Health and Nutrition Examination Survey, 1971-1975. Bilateral osteoarthritis was more prevalent (5%) than unilateral osteoarthritis (2%). Bilateral osteoarthritis was twice as prevalent in women as in men; however, there was no sex difference in the prevalence of unilateral osteoarthritis. Odds ratios calculated by means of polychotomous logistic regression indicated that obesity, knee injury, and age were significantly associated with both unilateral and bilateral knee osteoarthritis. Obesity was a stronger predictor of bilateral osteoarthritis than was knee injury (odds ratio (OR) = 6.6 for obesity, 3.5 for right knee injury, and 3.0 for left knee injury; 95% confidence interval (CI) 4.71-9.18, 1.80-6.83, and 1.51-6.11, respectively). Knee injury was a stronger predictor of unilateral osteoarthritis than was obesity (OR = 3.4 and 2.4 for obesity in the right and left knee, respectively (95% CI 1.55-7.29 and 0.96-5.75) and OR = 16.3 and 10.9 for injury in the right and left knee, respectively (95% CI 6.50-40.89 and 3.72-31.93]. These findings suggest that different pathogenetic processes may exist for unilateral and bilateral knee osteoarthritis.

Age Factors↗
PubMedDate not supplied

The efficacy of a prophylactic knee brace to reduce knee injuries in football. A prospective, randomized study at West Point.

The purpose of this prospective, randomized study was to determine the efficacy of a prophylactic knee brace to reduce the frequency and severity of acute knee injuries in football in an athletic environment in which the athletic shoe, playing surface, athlete-exposure, knee injury history, and brace assignment were either statistically or experimentally controlled. The participants in the study were 1396 cadets at the United States Military Academy, West Point, New York, who experienced a total of 21,570 athlete-exposures in the 1986 and 1987 fall intramural tackle football seasons. The use of prophylactic knee braces significantly reduced the frequency of knee injuries, both in the total number of subjects injured and in the total number of medial collateral ligament injuries incurred. However, the reduction in the frequency of knee injuries (total and medial collateral ligament) was dependent on player position. Defensive players who wore prophylactic knee braces had statistically fewer knee injuries than players who served as controls. This was not true of offensive players who served as controls; they had statistically no difference in the number of knee injuries from players who wore prophylactic knee braces. The severity of medical collateral ligament and anterior cruciate ligament knee injuries was not significantly reduced with the use of prophylactic knee braces.

Adult↗
PubMed1991

Knee manipulation following total knee arthroplasty. Analysis of prognostic variables.

In an effort to identify prognostic indicators for knee manipulation, the authors retrospectively reviewed the records of 60 osteoarthritic patients with posterior stabilized knee implants who required manipulation (94 knees) between January 1984 and December 1986. They also studied the records of 28 consecutive osteoarthritic patients who were implanted with 41 posterior stabilized knees between January 1985 and September 1985 whose knees did not require manipulation (control group). In both patient groups the following parameters were assessed and compared: overall knee alignment, joint line elevation, anterior to posterior (AP) dimension of the knee, AP placement of the tibial component, patellar height, obesity, age, preoperative flexion, time of manipulation, single vs bilateral knee implants, final flexion, final Hospital for Special Surgery (HSS) score, and the development of heterotopic ossification. The findings of this study showed that an increase in the AP knee dimension by 12% or greater was a critically independent variable that significantly predisposed patients to manipulation. They also show that quadriceps adhesions were another major factor leading to manipulation, and that rupturing of these adhesions led to an increase in heterotopic ossification. This review also indicated that 3 months after knee arthroplasty was a significant time for evaluation because knee flexion and HSS score at this point in the patient's recovery positively correlated with the final HSS score.

Aged↗
PubMedDate not supplied

[Kinematics of various joint mechanisms for the prosthetic substitution of the knee joint following knee exarticulation].

In the past, long amputation stumps of the thigh after knee disarticulation were difficult to fit with a knee prosthesis. Apart from other difficulties, one essential problem was caused by the fact that in preservation of the femoral length there was little or even no space to assemble a knee prosthesis at the level of the axis of the natural knee joint, that is to say at a position somewhere within the femoral condyles. In the meantime the number of knee disarticulations has increased and thus substituted the conventional above knee amputation. Consequently some new, partly polycentric knee joint mechanisms have been designed for the prosthetic fitting of knee disarticulation stumps as well as for long amputation stumps of the thigh. These mechanisms try to cope with the space problem in different ways and, moreover, some of them can also produce a moving centre of rotation at joint flexion similar to the natural knee joint. The motion pattern in current knee joint mechanisms is investigated by graphical construction of their centrodes and it is compared to the motion pattern of the natural knee joint.

Artificial Limbs↗
PubMed1978

Knee lock device for knee ankle orthoses for spinal cord injured patients: an evaluation.

The effect of a specially designed knee lock in a knee ankle orthosis was studied in 2 able-bodied volunteers and in 2 patients with spinal cord lesions. This lock allows the knee to bend during the swing phase but locks the knee securely during the stance phase. The device is intended to improve gait pattern and reduce oxygen consumption more than a standard knee lock which keeps the knee straight throughout the entire gait cycle. Energy savings with the knee locking mechanism were significant only at ambulation rates at or above 73 meters/min, a speed which could only be attained by able-bodied subjects. To achieve such high rates of ambulation a patient's hip flexors must be strong; yet a knee ankle orthosis is required only when the patient's knee extensors are weak. In patients with spinal cord injuries, this pattern of muscle strength is rarely encountered. The innervation of hip flexors or knee extensors overlaps, so voluntary control of these muscles will either be present or absent for both muscle groups. Therefore, most spinal cord injured persons who need a knee orthosis would not greatly benefit from this locking mechanism. There may be other conditions in which this device will prove valuable.

Adult↗
PubMed1992

Anterior knee pain in rheumatoid patients after total knee replacement. Possible selection criteria for patellar resurfacing.

Postoperative anterior knee pain was evaluated in a consecutive series of 138 knees in 108 patients with rheumatoid arthritis treated by total knee replacement with Mark I Insall-Burstein prostheses. No knee had primary patellar resurfacing, and in the 119 knees followed up for a mean of 63.9 months, none had secondary resurfacing. Anterior knee pain was absent in 87 knees (73%), mild in 16 (13.5%) and moderate or severe in 16 (13.5%). The height of the patella above the prosthetic joint line was the only variable which was directly related to the incidence of anterior knee pain. The sensitivity and specificity of patellar height measurements for identifying patients with or without pain were derived. From these data, a selective policy of resurfacing the patella in those at risk was adopted. Choosing a patellar height of 15 mm or less, patellar resurfacing could be avoided in 80% of patients likely to have no pain, and the patella could be resurfaced in 65% of those likely to have anterior knee pain.

Adult↗
PubMed1991

Posteriorly stabilised (Insall-Burstein) total condylar knee arthroplasty. A follow-up study of 157 knees.

We reviewed 157 knees in 118 patients who underwent posteriorly stabilised (Insall-Burstein) knee replacement arthroplasty. Their mean age at operation was 69 years (range 47 to 85 years) and the average follow-up was 3.5 years (range 2 to 7 years). The "BASK" knee function assessment chart was utilised to evaluate the functional and clinical results. One hundred and thirty-five knees (86%) had excellent or good results, 16 knees (10%) had fair results and six (4%) had poor results. The mean postoperative BASK score was 79 points and the average postoperative knee flexion was 95 degrees (range 65 degrees to 130 degrees). Two patients had a superficial infection, one deep sepsis requiring revision arthroplasty and two mechanical loosening. Patellar impingement symptoms were present in 8% of the knees, although they were troublesome in less than half. Varus alignment of the knee and a varus tilt of the tibial component of more than 2 degrees correlated with the incidence of radiolucent lines around the tibial prosthesis. 90% of the patients were pleased or satisfied with the functional result. The total condylar knee is a safe, reliable and versatile prosthesis.

Aged↗
PubMed1992

Correlates of knee pain among US adults with and without radiographic knee osteoarthritis.

We examined the associations of sociodemographic variables, health behaviors, health status and psychological well being with radiographic knee osteoarthritis (OA) and self-reported knee pain for 4056 US adults aged 45-74 years. Among persons with or without knee OA known correlates of radiographic knee OA (age, sex, race, obesity) were generally not associated with knee pain. Radiographic severity, psychological well being and health status were associated with knee pain, both among persons with and without radiographic knee OA, suggesting that nonradiographic correlates of self-reported knee pain are independent of whether a person has radiographic knee OA.

Age Factors↗
PubMed1991

Occupational physical demands, knee bending, and knee osteoarthritis: results from the Framingham Study.

We sought to assess occupational joint use and osteoarthritis (OA) longitudinally in a large population with multiple occupations. Subjects were members of the Framingham Heart Study cohort followed over 40 years with occupational status assessed at the beginning of the Heart Study [from Examination 1 (1948-51) through Examination 6 (1958-61)] and knee OA assessed by weight bearing knee radiograph at Examination 18 (1983-85) when mean age of subjects was 73 years. Each subject's job was characterized by its level of physical demand and whether the job was associated with knee bending. Odds ratios (OR) testing the association of job demand with OA were adjusted by logistic regression for age, body mass, knee injury history, smoking, and educational level. Men whose jobs required knee bending and at least medium physical demands had higher rates of later radiographic knee OA (at least definite osteophytes) than men whose jobs required neither (43.4 vs 26.8%; OR of OA = 2.22, 95% CI 1.38, 3.58). Rates of severe radiographic OA (osteophytes and joint space narrowing) and of bilateral radiographic OA were also significantly increased in these men. Few women had jobs requiring knee bending or that were physically demanding and these jobs were generally unassociated with later radiographic OA. Only a small number of men (n = 28) had symptomatic knee OA, and we could not confirm that it was associated with occupation in men. Thus, among men, occupations which combine knee bending and physical demands may be an important cause of radiographic OA.

Aged↗
PubMed1990

Knee flexor/extensor strength ratio in follow-up of acute knee distortion injuries.

This study evaluated the peak torque and total work hamstring/quadriceps (HQ) ratios of 77 knees with a previous grade I distortion injury to find the possible relationship between different HQ ratios and long-term outcome. For measurement of quadriceps and hamstrings strengths, the CYBEX II isokinetic dynamometer was used. Peak torque values were recorded at low (60 degrees/sec) and high (180 degrees/sec) speeds of isokinetic movement, and the maximal isometric extension and flexion outputs were measured with the knee at a 60 degree angle. Three standardized knee scoring scales were used to determine the subjective, functional, clinical, and radiologic outcome of the injured knees. In every test, great intersubject variation of the HQ ratio was observed, even in healthy knees (range 19% to 148%). Follow-up scores of the groups with low (less than 50%), optimal (50% to 80%), or high (greater than 80%) HQ ratios of the injured knees did not differ significantly from each other. However, in every test the scores were significantly (p less than 0.001 to less than 0.0001) better in patients whose injured knee HQ ratio was nearly identical (less than or equal to 15%) rather than clearly different from (greater than 15%) the uninjured knee. These findings confirm our previous observation that the HQ ratio is an idiosyncratic parameter. Any general recommendation about optimal value is difficult to give. In evaluating long-term outcome, the most ideal HQ ratio of an injured knee seems to be the HQ ratio of the opposite, healthy extremity.

Adolescent↗
PubMed1991

Knee ligament injuries combined with ipsilateral tibial and femoral diaphyseal fractures: the "floating knee".

The incidence of rupture of the knee ligaments was retrospectively studied in 47 patients with ipsilateral fractures of the femoral and tibial diaphyseal shaft. Fifteen patients proved to have an instability of the knee at the time of follow up. Disruption of the knee ligaments had not been recognised initially. At the time of initial treatment, injury of the knee ligaments had been diagnosed in only three cases. After stabilisation of both fractures in these cases, the knee ligaments had been repaired; at re-examination these patients had no complaints and their knees were perfectly stable. In view of the high incidence of missed cases, the possibility of disruption of the knee ligaments should be considered in all patients with fractures of both the femoral and tibial shaft. Meticulous examination of the knee at the time of injury is strongly advocated.

Femoral Fractures↗