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Biomedical subjects

F R Noyes

Publications and source records attributed to F R Noyes.

At least 19 recordsLinked to original sources
PubMed1999

Assessment of sports participation levels following knee injuries.

Although there are many published instruments designed to determine outcome following the treatment of knee injuries, only a few incorporate specific assessments of sports activity level and participation into the evaluation. This article reviews 3 of the most commonly used sports activity outcome instruments: the scales devised by Tegner and Lysholm, the Hospital for Special Surgery and the International Knee Documentation Committee. Problems and potential study biases that can arise with improper questionnaire design and data reduction techniques are reviewed, and recommendations are made to correct these problems. The problems identified include: (i) the failure to precisely define sports activity levels according to a specific sport and intensity of participation; (ii) the failure to sort populations according to overall intensity of athletic participation both before and after treatment; (iii) the failure to detect and sort from the population patients who return to sports and experience significant symptoms; (iv) the combination of work and sports activities into the same scale; and (v) the failure to detect alterations in sports participation caused by changes in lifestyle or non-knee-related factors. We have developed a sports assessment instrument, the Cincinnati Sports Activity Scale (CSAS). The methodology used to create this scale, its use in the assessment of return to or change in sports activities, and the assessment of specific functions of daily and sports activities, are briefly reviewed. The CSAS is based on 2 criteria: (i) the frequency of participation; and (ii) the general types of forces experienced by the lower extremity during the sport. The assessment of change in sports activities accounts for modifications in lifestyle and can also detect patients who have returned to sports but are experiencing significant symptoms and problems. Examples of data reduction and reporting are provided to represent practical situations from a prior investigation.

Activities of Daily Living↗
PubMed1998

Physical and arthroscopic examination techniques of the patellofemoral joint.

A systematic approach to the clinical history, physical, and arthroscopic examination of patellofemoral disorders will lead to improved diagnostic accuracy and clinical treatment success. We review important aspects of physical and arthroscopic examination of patellofemoral disorders Basic and advanced physical examination techniques are presented, and their clinical significance is reviewed. Arthroscopic examination of the patellofemoral joint is used as an adjunct to physical examination to evaluate chondral lesions of the patella and femoral sulcus and to visualize patella tracking. Techniques to assess patellar tracking and the integrity of patellar restraints and to grade chondral lesions are outlined. Utilization of these techniques will improve clinical studies on the treatment of patellofemoral disorders.

Arthroscopy↗
PubMed1998

Decrease in knee joint pain and increase in function in patients with medial compartment arthrosis: a prospective analysis of valgus bracing.

We studied a brace designed to decrease loads on the medial tibiofemoral compartment in knees with chronic pain and arthrosis to determine if pain symptoms decreased, function improved, and dynamic gait characteristics altered during walking. Eighteen patients with symptomatic medial compartment arthrosis were fitted with a commercially available brace. All were evaluated after an average of 9 weeks of brace wear, and 13 patients were evaluated after 1 year of brace wear. The Cincinnati Knee Rating System and additional pain scales were used to analyze symptoms and functional limitations. Nine subjects underwent a dynamic gait analysis and were compared with a control group of 11 normal subjects matched for age and walking speed. The brace was worn an average of 7 hours a day, 5 days a week. Following 9 weeks of brace wear, statistically significant improvements were found for all pain parameters, and these improvements continued at the 1 year evaluation. Before brace wear, 78% had pain with activities of daily living, but after the first evaluation, only 39% continued to have such pain, and at the second evaluation, only 31% were so affected. Before brace wear, patients had a walking tolerance of 51 minutes prior to the onset of pain symptoms. At the first evaluation, patients could walk 138 minutes without pain, and after 1 year, they could walk 107 minutes without pain. Before brace wear, 78% rated their overall knee condition as fair or poor whereas at the first evaluation, only 33% continued to provide this rating. No differences were found in the dynamic gait parameters measured with and without the brace. While this brace did not provide the dramatic improvements in symptoms, function, and patient satisfaction obtainable after high tibial osteotomy, it did help the majority of patients. If the goal of brace use is to buy a short amount of time for patients who cannot undergo or wish to avoid osteotomy or knee arthroplasty, then bracing appears to offer a reasonable alternative for short-term pain relief and improved function.

Adult↗
PubMed1997

A comparison of results of arthroscopic-assisted anterior cruciate ligament reconstruction between workers' compensation and noncompensation patients.

This investigation compared the results of arthroscopic-assisted anterior cruciate ligament patellar tendon autogenous reconstruction in patients who received Workers' Compensation (WC) benefits with results of similar surgery in patients who did not receive such benefits, to determine if differences existed based on this variable alone. Thirty-eight patients (19 WC benefits, 19 NoWC) were matched for age, injury chronicity, number of prior operations, and months of follow-up. All had the same operation and rehabilitation. A significant difference was found between the groups in the mean number of days of lost employment preoperatively (WC, 122 days; NoWC, 3 days) and postoperatively (WC, 222 days; NoWC, 37 days). At follow-up (mean, 27 months), 17 patients in group WC had returned to work (6 with symptoms) and 2 were disabled. All patients in group NoWC had returned to work, 2 with symptoms. There was no significant difference between the groups for anterior-posterior displacements, functional limitations with daily or sports activities, patient perception of the knee condition, the overall rating score, or complications. The number of mean days of lost employment in group WC could not be accounted for from factors that normally effect anterior cruciate ligament reconstruction results. We hypothesize that other factors such as wage systems that support WC injuries long-term, inability of employers to modify job requirements, inability of employees to receive job retraining, or lack of proper immediate diagnosis and treatment of the injury, may have lead to the large number of lost working days in group WC.

Absenteeism↗
PubMed1997

Arthroscopic-assisted allograft anterior cruciate ligament reconstruction in patients with symptomatic arthrosis.

We reviewed the results of arthroscopic-assisted anterior cruciate ligament (ACL) allograft reconstruction in 40 patients who had advanced articular cartilage deterioration documented by arthroscopy during the reconstruction. A mean of 7 years had elapsed between the original injury and the reconstruction, and 102 prior operative procedures had been done in 34 of the 40 patients. A total of 64 articular cartilage lesions were noted; 34 knees had lesions in the medial or lateral tibiofemoral compartment. Postoperatively, all had immediate motion and early functional rehabilitation. The results were assessed using the Cincinnati Knee Rating System. At follow-up (mean, 37 months), significant improvements were found for pain, giving-way, and functional limitations with daily and sports activities (P < .01). Fifty-five percent had returned to mostly light athletics (avoiding high impact sports) based on our advice and were asymptomatic. The mean overall rating scores significantly improved (P < .0001, mean improvement 22 points). We concluded that the majority of patients in this study with chronic ACL rupture and post-traumatic arthrosis benefited short-term from arthroscopic-assisted ACL reconstruction.

Adult↗
PubMed1996

Lower limb alignment and foot angle are related to stance phase knee adduction in normal subjects: a critical analysis of the reliability of gait analysis data.

Anatomic and mechanical factors that affect loading in the knee joint can contribute to pathologic changes seen at the knee in degenerative joint disease and should be considered in treatment planning. The objectives of this study were to quantify the relationships between the alignment of the bones of the lower extremity, foot progression angle, and knee adduction moment, and to determine the reliability of our gait measurements. Gait analysis and complete radiographic evaluation of the lower extremity were performed on 11 healthy subjects. The gait measurements were recorded with an optoelectronic digitizer and a multi-component force plate. The subjects who had radiographic measurements indicative of varus alignment of the lower extremity had statistically higher peaks in knee adduction moment in early stance. Conversely, those with valgus alignment of the lower extremity had statistically lower peaks in knee adduction moment in early stance. The subjects who had a large toe-out angle and low ankle inversion moment peaks in late stance had significantly lower peaks in knee adduction moment in late stance. These significant (low to moderate) correlations suggest that the limbs with more valgus alignment and those with a toe-out gait exhibited a reduced peak adduction moment at the knee. To verify the reproducibility of the data, gait analysis testing was performed on each lower limb on 2 separate days for each subject. Analysis of variance showed that there was no significant difference between test limbs or test days for each subject. Our results suggest that the alignment of the lower limb and the foot progression angle, which can be readily measured in a clinical setting, can serve as predictors of knee joint loading in healthy individuals. These findings may have important implications for both surgical and nonsurgical treatment of abnormalities of the knee joint.

Adult↗
PubMed1996

Effect of tibial attachment location on the healing of the anterior cruciate ligament freeze model.

We studied the healing response of a devitalized anterior cruciate ligament to a treatment of initial anterior-posterior joint translation in goats. Devitalization and devascularization were achieved by five successive freeze-thaw cycles. Anterior-posterior translation was surgically altered by an osteotomy of the tibial attachment of the devitalized ligament and its reattachment either in the anatomical position or in a position 5 mm posterior. Six weeks after the first surgery, the same procedure was performed on the contralateral limb, except that the ligament was reattached in the alternate position. Six months after the initial surgery, femur-anterior cruciate ligament-tibia specimens were tested to determine their structural and mechanical material properties. Anatomic ligament placement resulted in reduced anterior-posterior translation (p < 0.05) and greater anterior joint stiffness (p < 0.05). Maximum load (p < 0.05) and ligament stiffness (p < 0.01) also were greater for the anatomically placed anterior cruciate ligaments. The maximum load for anatomically placed ligaments averaged 1.625 +/- 211 N (SEM). The strength of the posteriorly placed anterior cruciate ligament, 895 +/- 164 N was similar to results of historical anterior cruciate autograft reconstructions. Ligament failure occurred near the tibial insertion in the posteriorly placed ligaments more often than in the anatomically placed ligaments (four of five times compared with one of five times). Ligament failure near the tibial insertion occurred with lower mean maximum load than failure at the midsubstance or by bone avulsion (796 compared with 1.592 N: p < 0.05). These data support the hypothesis that ligament laxity is important to the healing and remodeling of anterior cruciate ligament grafts.

Animals↗
PubMed1996

Revision anterior cruciate ligament surgery: experience from Cincinnati.

Prospective studies were done to determine the outcome of allografts and autografts used for revision anterior cruciate ligament reconstruction. The allograft group was comprised of 65 patients observed for a mean of 42 months postoperatively; the autograft (bone-patellar ligament-bone) group contained 20 patients observed for a mean of 27 months postoperatively. KT-2000 testing and a comprehensive knee examination were done on all the patients. The Cincinnati Knee Rating System was used for assessment. Significant improvements were noted in all patients for symptoms, functional limitations, anteroposterior displacements, pivot shift tests, and overall rating scores. KT-2000 results showed 53% of the allograft group and 67% of the autograft group had less than 3 mm increased displacement (not statistically significant). The overall failure rates were 33% for the allografts and 27% for the autografts. Preoperative planning and technical aspects of anterior cruciate ligament revision procedures are described. The authors prefer bone-patellar ligament-bone autografts for anterior cruciate ligament revision, although the data presented were considered preliminary. Bone-patellar ligament-bone allografts may be used when autogenous tissues are not available, because they offer reasonable success rates for patients who are symptomatic with daily activities.

Adolescent↗
PubMed1996

Reconstruction of the anterior cruciate ligament with human allograft. Comparison of early and later results.

Sixty-eight patients who had had reconstruction of an acute rupture of the anterior cruciate ligament with either a fascia lata or a bone-patellar ligament-bone allograft returned for two follow-up evaluations, at two to four years and at five to nine years (mean, seven years) postoperatively. The early (two to four-year) results in these patients have been reported previously. The mean time between the early and the later evaluation was fifty-six months (range, twenty to ninety-six months). At the early evaluation, fifty-two (78 per cent) of the sixty-seven patients who were tested with an arthrometer at eighty-nine newtons had less than three millimeters of increased anterior-posterior displacement compared with that of the contralateral limb; at the later evaluation, fifty-four (79 per cent) of the sixty-eight patients had this finding (p=0/97). With use of arthrometric and pivot-shift-test data, forty-eight (75 per cent) of sixty-four grafts were classified as functional at the early evaluation and fourteen (22 per cent), as partially functional; two (3 per cent) had failed. (Four grafts could not be classified because of incomplete data.) At the later examination, fifty (74 per cent) of the sixty-eight grafts were functional, thirteen (19 per cent) were partially functional, and five (7 per cent) had failed. At the early evaluation, sixty-two (93 percent) of sixty-seven patients had no palpable patellofemoral crepitus and five (7 per cent) had moderate crepitus. At the later evaluation, fifty-one (75 per cent) of the sixty-eight patients continued to have no crepitus, sixteen (24 per cent) had moderate crepitus, and on (1 per cent) had severe crepitus. An increase in crepitus between the early and the later evaluation was found in twelve (19 per cent) of the sixty-two patients who had normal crepitus at the early evaluation. With the numbers available, no factor, such as the type of graft, associated ligamentous injury, or meniscal repair, correlated significantly with the amount of patellofemoral crepitus at either follow-up evaluation. At the early evaluation, the result was rated excellent or good for thirty-eight (60 per cent) of sixty-three patients, fair for twenty-one (33 per cent), and poor for four (6 per cent). (The result could not be rated for four patients because of incomplete data.) At the later evaluation, the result was rated excellent or good for forty-five (66 per cent) of the sixty-eight patients, fair for eighteen (26 per cent), and poor for five (7 per cent). For nine patients (13 per cent), the over-all rating deteriorated from excellent or good at the early evaluation to fair or poor at the later examination. For six patients (9 per cent), the rating improved from fair at the early evaluation to excellent or good at the later evaluation. With the numbers available, we could detect no significant decrease in anterior-posterior displacement of the knee, patellofemoral crepitus, the pain or the jumping score, or the over-all knee rating over the time-period studied. While we currently recommend arthroscopically assisted reconstruction with a bone-patellar ligament-bone autogenous graft as the first choice for an acute rupture of the anterior cruciate ligament, our study shows that favorable results can be obtained with allografts and justifies their use when the surgeon and patient choose this approach.

Acute Disease↗
PubMed1996

Technical considerations in the management of complex meniscus tears.

Meniscal repair continues to be an important procedure in patients with meniscal tears. The orthopedic literature has recommended excision of complex tears or tears that are located in the central avascular region. For the past 13 years, the authors have repaired all meniscal tears that can be reduced anatomically and that have healthy tissue that will support the multiple sutures required for a stable repair, regardless of tear pattern or location. Correct patient selection criteria continue to be important. In all cases, the risks of complications and retear must be considered carefully and judged against the potential benefits of repair. A postoperative rehabilitation program that allows early range of motion, and progression of weight bearing is not detrimental to the healing process if the repair is stable. Close postoperative follow-up examinations are necessary to determine the incidence of meniscal symptoms; however, the absence of joint line pain, catching, locking, or effusion does not guarantee complete healing of the tear. Follow-up arthroscopy is currently the most accurate method to determine if complete or partial healing has occurred.

Adolescent↗
PubMed1996

Posterior cruciate ligament anatomy and length-tension behavior of PCL surface fibers.

The location of the most nearly isometric region of the PCL has remained a controversial issue. Our data indicate that there is an entire region close to the PCL's proximal edge that is isometric; however, the majority of the PCL is anisometric. This concurs with the work of Grood et al, Ogata and McCarthy, and Sidles et al. However, other authors believe that the posterior-proximal region of the PCL contains the most isometric fibers. These differences could be explained in part through the differences in experimental design. It is important to note that all of these studies placed the most nearly isometric area within the substance of the ligament. What is equally important to understand from all of these studies is the complex length change pattern of fibers comprising the PCL. The function of PCL fibers is not accurately described by the traditional model of an anterolateral bundle and a posteromedial bundle that have reciprocal functions. Further kinematic studies testing potential femoral attachment sites are needed to ascertain the optimal placement for PCL graft substitutes. An earlier study performed in our laboratory suggested that PCl graft placement distal to the isometric region, 4 mm from the proximal edge (within the PCL footprint), provided the most optimal position for correcting abnormal posterior translation after PCL division. We reported that isometric placement at the time of surgery would lead to incorrect positioning of the graft. We are currently investigating alternative graft configurations (eg, two-bundle and multiple-bundle grafts) to determine if PCL function can be reproduced more ideally; however, more analysis is required before definitive recommendations can be made. At present, the ideal operative procedure for PCL reconstruction requires continued biomechanical analysis followed by carefully designed clinical trials.

Humans↗
PubMed1994

The effects of 4 Mrad of gamma irradiation on the initial mechanical properties of bone-patellar tendon-bone grafts.

Pairs of frozen human patellar tendon-bone (PTB) ligament allografts were exposed to either 0 or 4 Mrad of gamma irradiation sterilization, the latter value based on recent reports suggesting higher dosage levels for adequate sterilization against the human immunodeficiency virus. All specimens were subjected to three levels of loading: lower functional loads, higher functional loads, and failure. Lower functional loads were simulated by performing in vitro static and cyclic creep tests, similar to loads that the surgeon and patient would apply before and after implantation, respectively. Higher functional loads, simulating moderate activities of daily living, were represented by the slope of the linear portion of the force-elongation curve or linear stiffness. Failure or trauma was then simulated by failing the grafts in tension at a high strain rate. We found that the irradiation treatment shortened the tendon by only 0.6 mm, which was nevertheless statistically significant (p < 0.01). By contrast, 4 Mrad did not significantly alter either static or cyclic creep (p > 0.05) at lower functional loads. Instead, irradiation produced the greatest changes during failure testing, reducing both the graft's linear stiffness by 12% (p < 0.025) and maximum force by 26% (p < 0.001). Although our data do not describe how an allograft might perform during the early healing and later collagen-remodelling phases, such in vitro studies remain important if we are to optimize allograft properties before arthroscopic anterior and posterior cruciate ligament reconstruction.

Adult↗