Thomas Limbird | Meharry Medical College (original) (raw)
Papers by Thomas Limbird
Southern Medical Journal, 1989
Slipped capital femoral epiphysis has been described in several syndromes associated with short s... more Slipped capital femoral epiphysis has been described in several syndromes associated with short stature and endocrine disturbances. I have presented a case of slipped capital femoral epiphysis in conjunction with Russell-Silver syndrome.
Medicine and Science in Sports and Exercise, 1992
The purpose of this project was to describe the injury experiences of athletes with disabilities.... more The purpose of this project was to describe the injury experiences of athletes with disabilities. A cross-disability instrument was developed to measure variables of interest. A retrospective survey was administered to 426 athletes who participated at the 1989 national competition of the National Wheelchair Athletic Association (NWAA), United States Association for Blind Athletes (USABA), and the United States Cerebral Palsy Athletic Association (USCPAA). The definition of injury was any trauma to the participant that occurred during any practice, training, or competition session that caused the athlete to stop, limit, or modify participation for 1 d or more. Thirty-two percent (N = 137) of the total respondents reported at least one time-loss injury. By organization, 26% of the total injuries were from the NWAA and 37% were from the USABA and USCPAA, respectively. The shoulder and arm/elbow accounted for 57% of the total NWAA injuries. Fifty-three percent of the injuries to the USABA athlete were to the lower extremity. Injuries to the USCPAA athlete were distributed among four body locations, knee (21%), shoulder (16%), forearm/wrist (16%), and leg/ankle (15%). The athlete with a disability demonstrated approximately the same percentage of injury as the athlete without a disability in similar sport activities. Biomechanical considerations of locomotion and specific sport skills should be analyzed by experts to reduce the percentage of injuries.
Journal of Computer Assisted Tomography, 1994
Clinical Orthopaedics and Related Research, 1985
Hemophilus influenzae is an uncommon, seldom considered pathogen of septic arthritis in adults. H... more Hemophilus influenzae is an uncommon, seldom considered pathogen of septic arthritis in adults. H. influenzae seems not to have been reported in association with a total joint infection. The majority of previously reported H. influenzae cases have been associated with joint trauma or preexisting joint disease. A 63-year-old woman with a late hematogenous infection due to H. influenzae of a total hip arthroplasty was treated by surgical debridement and appropriate antibiotics. In a short-term follow-up evaluation of one year, this treatment was successful in allowing retention of the prosthesis and return to satisfactory function.
Clinical Orthopaedics and Related Research, 1990
It has been recognized for many years that the vascular supply to the meniscus has been extremely... more It has been recognized for many years that the vascular supply to the meniscus has been extremely important in the potential for healing of a repaired meniscus. Early experimental work confirmed that meniscal defects that communicated with the peripheral vascular network would heal if repaired. However, those tears that did not communicate with the vascular bed would not heal even if repaired. Unfortunately, there has been no clinically applicable technique for evaluating blood flow in the torn meniscus. Experimental procedures using laser Doppler flowmetry have shown this to be a precise and simple tool for the evaluation of meniscal blood flow. Applications of this technique in the clinical situation show great promise in enabling the surgeon to make a decision to repair or remove the torn meniscus based on the blood flow in the remaining vascular bed.
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 1993
Chronic synovitis is an unusual manifestation of sarcoidosis but may be significantly disabling. ... more Chronic synovitis is an unusual manifestation of sarcoidosis but may be significantly disabling. Arthroscopic synovectomy can provide an excellent result, relieving discomfort and arresting the disease process, and should be considered in any patient whose synovitis has not responded to medical management. Key Words: Arthroscopic synovectomy--Sarcoidosis--Synovitis.
Journal of Bone and Joint Surgery American Volume, Nov 1, 1996
Amer J Sport Med, 1988
The functional microcirculatory system of the meniscus was investigated in nine sheep using laser... more The functional microcirculatory system of the meniscus was investigated in nine sheep using laser Doppler flowmetry (LDF). The highest blood flows recorded were found at the periphery and at the anterior and posterior horns, and this finding was confirmed by india ink injections in five sheep and by meniscal autoradiographs following intraatrial injection of 20 million Cs46 microspheres in four sheep. LDF provides accurate and reproducible assessment of meniscal blood flow. If adequate probes can be developed, this method offers great promise in the clinical assessment of blood flow within the substance of meniscal tears, thus offering the surgeon initial information in the decision to repair or resect a meniscal tear.
The Journal of Bone and Joint Surgery American Volume, Feb 1, 1992
We reviewed the results of treatment of forty open diaphyseal fractures of the lower extremity in... more We reviewed the results of treatment of forty open diaphyseal fractures of the lower extremity in thirty-five children. The patients were between three and sixteen years old, and they had been managed between 1980 and 1988. The minimum duration of follow-up was one year. Eighty-six per cent of the patients had been injured in a motor-vehicle accident, and 74 per cent had associated injuries. Thirty-one of the fractures were Grade-II open or Grade-III open and seven were Grade-I open, according to the classification of Gustilo and Anderson. Two patients who had initially had a closed fracture were treated with a fasciotomy for a compartment syndrome, so these two fractures were included as open. Four other patients who had a Grade-II or III open fracture also needed a fasciotomy. All wounds were treated with immediate and repeat débridement and early soft-tissue coverage. Twenty-two fractures healed primarily. There were three early amputations. Twelve fractures that healed after six months were classified as delayed unions and three fractures were classified as non-unions because of the absence or arrest of healing, as seen on serial roentgenograms. Additional intervention was used to achieve union of eight of the fifteen fractures that had been classified as a delayed union or a non-union. Ten of the forty fractures were associated with infection, but osteomyelitis developed in only one patient. No patient had a growth arrest. Only one patient had a limb-length discrepancy that was more than two centimeters. Three early amputations and one delayed amputation were performed in patients who had a Grade-IIIC open fracture.
The Journal of arthroplasty, 2007
Although airway obstruction secondary to cricoarytenoid arthritis is an infrequent perioperative ... more Although airway obstruction secondary to cricoarytenoid arthritis is an infrequent perioperative complication of rheumatoid arthritis, it must be promptly recognized and appropriately managed to avoid fatal consequences. We report a case of cricoarytenoid dysfunction leading to acute respiratory insufficiency requiring tracheostomy in the immediate postoperative period after total knee arthroplasty in a patient with severe rheumatoid arthritis.
Southern medical journal, 1987
We have described a 39-year-old woman with Maffucci's syndrome, large mediastinal hemangiomas... more We have described a 39-year-old woman with Maffucci's syndrome, large mediastinal hemangiomas, infiltrating adenocarcinoma of the breast, and pituitary adenoma. This is the fifth reported case of Maffucci's syndrome with a coexistent pituitary adenoma, a frequency that cannot be explained by chance alone. There has been only one previously reported case in which the patient had a widened mediastinum, but the etiology was not discussed. Three of the four previously described patients with Maffucci's syndrome and a pituitary adenoma also had a proven or possible associated epithelial neoplasm. While this association is tenuous, it is considered worthy of comment.
Southern Medical Journal, 1990
Medicine & Science in Sports & Exercise, 1994
Three cervical orthoses often used in football to prophylactically limit motion and prevent the n... more Three cervical orthoses often used in football to prophylactically limit motion and prevent the nerve injury known as "burners" were evaluated to determine their performance in limiting both hyperextension and lateral bending of the cervical spine. These orthoses have been used almost entirely on an empiric basis with little objective data to evaluate performance. A rope and pulley mechanism was used to pull the neck into hyperextension and lateral motion, with the only restraint being the various products tested. These trials were videotaped and the restriction provided by the collars was calculated from goniometric analysis of the projected images. These tests were performed to determine which products limit the mechanisms of the "burner" injury and thereby assess which braces might reduce or prevent the occurrence of these injuries. The results of the investigation indicate that all braces studied provided some degree of limitation in one of the mechanisms of injury, hyperextension. One brace performed superiorly in this respect. However, the other mechanism of injury, lateral bending, is inconsistently limited.
Journal of Orthopaedic Research, 1988
A tear of the anterior cruciate ligament (ACL) disrupts the delicate balance of static stabilizer... more A tear of the anterior cruciate ligament (ACL) disrupts the delicate balance of static stabilizers of the knee, leading to significant alterations in joint kinematics. Little is known about the dynamic compensatory responses of the patient to these kinematic alterations. This lack of quantitative information on the muscle synergy patterns has limited the surgeon's ability to evaluate various operative and rehabilitative techniques. Twelve subjects with documented ACL deficiency for at least 1 year and 15 normal participants were studied. Each subject was asked to walk at free and fast speeds on a 12 m walkway. The right and left foot contact patterns and the linear envelopes from the surface electromyogram (EMG) patterns of the gastrocnemius, medial and lateral hamstrings, rectus femoris, and vastus lateralis were measured. Significant differences were found in the muscle synergy patterns during walking. During the swing-to-stance transition, the ACL-deficient subjects showed significantly less activity in the quadriceps and gastrocnemius muscles and more activity in the biceps femoris than in the normal group. During early swing, the vastus lateralis is more active than normal, and during midstance and terminal stance, the hamstrings appear to be less active than normal subjects. These dynamic compensatory mechanisms suggest that use of the hamstring tendons in reconstructive procedures may alter important compensatory mechanisms about the knee joint. Application of dynamic EMG techniques to the study of reconstructive procedures should provide additional information that will assist the clinician in the rational choice of a surgical procedure.
Journal of Orthopaedic Research, 1992
We wished to determine whether anterior cruciate ligament (ACL) injury caused changes in patterns... more We wished to determine whether anterior cruciate ligament (ACL) injury caused changes in patterns of activity of individual or groups of muscles that control the knee joint. The electromyographic (EMG) patterns of six muscles in 26 individuals with uninjured knees and 20 individuals with ruptured ACL were studied during free and fast speed walking. A previously developed clustering technique was used for analysis. This technique involves making the Fourier transform of the average linear envelope (LE) of each muscle for each subject and using the amplitude and phase angles of the lower frequency harmonics as features to describe a pattern. These features are then grouped to subdivide the population of EMG patterns into different types. The results of analyses on single muscles showed that there exists a typical or "normal" pattern for each muscle which most uninjured and some injured subjects exhibit as well as several atypical patterns which mostly injured subjects exhibit, and that the atypical patterns are much more evident at fast walking speed. The characteristics of atypical patterns with respect to normal include time shifts in the peak of major phases of activity, the absence of a second phase of activity, and the existence of additional phases of activity. Synergy analysis showed that if one muscle has an atypical pattern, then several do; i.e., ACL injury induces major changes in the control strategy of the knee. The implications are that for rehabilitation programs one must focus on the training and strengthening of more than one muscle, and that for reconstructive procedures the changes in mechanics of the joint can possibly induce a significant change in its control strategy.
Journal of Orthopaedic Research, 1987
The purpose of this study was to quantitate the blood flow of the anterior cruciate ligament in v... more The purpose of this study was to quantitate the blood flow of the anterior cruciate ligament in vivo. Functional flow was evaluated using laser Doppler flowmetry (LDF), for which the output signal, blood cell flux (BCF), is expressed in terms of volts. Ten patients undergoing routine arthroscopic surgery with clinically intact anterior cruciate ligaments were selected at random for participation in the study. Under arthroscopic visualization, a 2.2-mm probe was placed through a trocar sleeve into the anterior cruciate ligament after the arthroscopic procedure. Pulsatile flow within the ligament was observed in all patients. The mean maximum BCF value ranged from 101 to 274 mV; SD range was +/- 3-9 mV. The mean minimum BCF ranged from 75 to 197 mV; SD range was +/- 0 to 9 mV. Laser Doppler flowmetry offers significant promise as a method for measurement of in vivo anterior cruciate and cruciate substitution blood flow.
Journal of Electromyography and Kinesiology, 1991
Anterior cruciate ligament (ACL) insufficiency and associated rotational instability of the knee ... more Anterior cruciate ligament (ACL) insufficiency and associated rotational instability of the knee joint is a potentially disabling condition. In particular, anterior-posterior laxity increases when the ACL is damaged and decreases with contraction of the hamstring musculature. Because laxity is controllable with muscle activity, comparison of muscular synergy patterns between groups of subjects with ACL-deficient and uninjured knees may identify compensatory mechanisms that could influence therapeutic procedures. All participants selected were between 18 and 40 years of age and had clinical or surgical documentation of ACL deficiency. Each subject was asked to walk and pivot with a stride time of 1 s on a 12-m walkway. The right and left foot-contact patterns and linear envelopes (LE) from the surface electromyographic (EMG) patterns of the gastrocnemius (GS), medial and lateral hamstring, rectus femoris (RF), and vastus lateralis (VL) were measured. Results from 15 subjects with uninjured knees and 12 subjects with ACL-deficient knees showed significant differences between their muscle synergy patterns. The types of differences observed depended on the stride period. All muscles within the ACL-deficient population showed some periods of abnormal activity. The differences in synergies indicate that there is a tendency for a greater net posterior force, flexor moment, and external rotation moment to be produced on the tibia during the time when most external rotation occurs to compensate for the mechanical actions of the lost ligament.
Journal of Electromyography and Kinesiology, 1991
A precise knowledge of the biomechanical alterations produced by anterior cruciate ligament (ACL)... more A precise knowledge of the biomechanical alterations produced by anterior cruciate ligament (ACL) damage would aid in selecting appropriate therapeutic intervention and monitoring rehabilitation. In an attempt to assess dynamic knee joint function, we compared the ground reaction force (GRF) and vertical couple patterns during walking and pivoting from an ACL-deficient population with those from a separate uninjured population. Statistical methods were used to quantitate the differences between the two populations for each force pattern in each functional task and to delineate the intervals of the force patterns in each functional task during which significant differences existed between the two populations. Our results indicate that significant differences exist between the GRF and vertical couple patterns of ACL-deficient subjects and uninjured subjects, but that onset and duration of these differences during stance phase vary among force components and tasks. The processing scheme extracts significant differences in the GRF and vertical couple patterns that would be lost in a comparison of a few pattern descriptors. Our results suggest that the vertical couple should be evaluated during assessment of pivoting maneuvers and show promise of providing useful information for assessment of knee dysfunction.
Journal of Biomechanics, 1987
Southern Medical Journal, 1989
Slipped capital femoral epiphysis has been described in several syndromes associated with short s... more Slipped capital femoral epiphysis has been described in several syndromes associated with short stature and endocrine disturbances. I have presented a case of slipped capital femoral epiphysis in conjunction with Russell-Silver syndrome.
Medicine and Science in Sports and Exercise, 1992
The purpose of this project was to describe the injury experiences of athletes with disabilities.... more The purpose of this project was to describe the injury experiences of athletes with disabilities. A cross-disability instrument was developed to measure variables of interest. A retrospective survey was administered to 426 athletes who participated at the 1989 national competition of the National Wheelchair Athletic Association (NWAA), United States Association for Blind Athletes (USABA), and the United States Cerebral Palsy Athletic Association (USCPAA). The definition of injury was any trauma to the participant that occurred during any practice, training, or competition session that caused the athlete to stop, limit, or modify participation for 1 d or more. Thirty-two percent (N = 137) of the total respondents reported at least one time-loss injury. By organization, 26% of the total injuries were from the NWAA and 37% were from the USABA and USCPAA, respectively. The shoulder and arm/elbow accounted for 57% of the total NWAA injuries. Fifty-three percent of the injuries to the USABA athlete were to the lower extremity. Injuries to the USCPAA athlete were distributed among four body locations, knee (21%), shoulder (16%), forearm/wrist (16%), and leg/ankle (15%). The athlete with a disability demonstrated approximately the same percentage of injury as the athlete without a disability in similar sport activities. Biomechanical considerations of locomotion and specific sport skills should be analyzed by experts to reduce the percentage of injuries.
Journal of Computer Assisted Tomography, 1994
Clinical Orthopaedics and Related Research, 1985
Hemophilus influenzae is an uncommon, seldom considered pathogen of septic arthritis in adults. H... more Hemophilus influenzae is an uncommon, seldom considered pathogen of septic arthritis in adults. H. influenzae seems not to have been reported in association with a total joint infection. The majority of previously reported H. influenzae cases have been associated with joint trauma or preexisting joint disease. A 63-year-old woman with a late hematogenous infection due to H. influenzae of a total hip arthroplasty was treated by surgical debridement and appropriate antibiotics. In a short-term follow-up evaluation of one year, this treatment was successful in allowing retention of the prosthesis and return to satisfactory function.
Clinical Orthopaedics and Related Research, 1990
It has been recognized for many years that the vascular supply to the meniscus has been extremely... more It has been recognized for many years that the vascular supply to the meniscus has been extremely important in the potential for healing of a repaired meniscus. Early experimental work confirmed that meniscal defects that communicated with the peripheral vascular network would heal if repaired. However, those tears that did not communicate with the vascular bed would not heal even if repaired. Unfortunately, there has been no clinically applicable technique for evaluating blood flow in the torn meniscus. Experimental procedures using laser Doppler flowmetry have shown this to be a precise and simple tool for the evaluation of meniscal blood flow. Applications of this technique in the clinical situation show great promise in enabling the surgeon to make a decision to repair or remove the torn meniscus based on the blood flow in the remaining vascular bed.
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 1993
Chronic synovitis is an unusual manifestation of sarcoidosis but may be significantly disabling. ... more Chronic synovitis is an unusual manifestation of sarcoidosis but may be significantly disabling. Arthroscopic synovectomy can provide an excellent result, relieving discomfort and arresting the disease process, and should be considered in any patient whose synovitis has not responded to medical management. Key Words: Arthroscopic synovectomy--Sarcoidosis--Synovitis.
Journal of Bone and Joint Surgery American Volume, Nov 1, 1996
Amer J Sport Med, 1988
The functional microcirculatory system of the meniscus was investigated in nine sheep using laser... more The functional microcirculatory system of the meniscus was investigated in nine sheep using laser Doppler flowmetry (LDF). The highest blood flows recorded were found at the periphery and at the anterior and posterior horns, and this finding was confirmed by india ink injections in five sheep and by meniscal autoradiographs following intraatrial injection of 20 million Cs46 microspheres in four sheep. LDF provides accurate and reproducible assessment of meniscal blood flow. If adequate probes can be developed, this method offers great promise in the clinical assessment of blood flow within the substance of meniscal tears, thus offering the surgeon initial information in the decision to repair or resect a meniscal tear.
The Journal of Bone and Joint Surgery American Volume, Feb 1, 1992
We reviewed the results of treatment of forty open diaphyseal fractures of the lower extremity in... more We reviewed the results of treatment of forty open diaphyseal fractures of the lower extremity in thirty-five children. The patients were between three and sixteen years old, and they had been managed between 1980 and 1988. The minimum duration of follow-up was one year. Eighty-six per cent of the patients had been injured in a motor-vehicle accident, and 74 per cent had associated injuries. Thirty-one of the fractures were Grade-II open or Grade-III open and seven were Grade-I open, according to the classification of Gustilo and Anderson. Two patients who had initially had a closed fracture were treated with a fasciotomy for a compartment syndrome, so these two fractures were included as open. Four other patients who had a Grade-II or III open fracture also needed a fasciotomy. All wounds were treated with immediate and repeat débridement and early soft-tissue coverage. Twenty-two fractures healed primarily. There were three early amputations. Twelve fractures that healed after six months were classified as delayed unions and three fractures were classified as non-unions because of the absence or arrest of healing, as seen on serial roentgenograms. Additional intervention was used to achieve union of eight of the fifteen fractures that had been classified as a delayed union or a non-union. Ten of the forty fractures were associated with infection, but osteomyelitis developed in only one patient. No patient had a growth arrest. Only one patient had a limb-length discrepancy that was more than two centimeters. Three early amputations and one delayed amputation were performed in patients who had a Grade-IIIC open fracture.
The Journal of arthroplasty, 2007
Although airway obstruction secondary to cricoarytenoid arthritis is an infrequent perioperative ... more Although airway obstruction secondary to cricoarytenoid arthritis is an infrequent perioperative complication of rheumatoid arthritis, it must be promptly recognized and appropriately managed to avoid fatal consequences. We report a case of cricoarytenoid dysfunction leading to acute respiratory insufficiency requiring tracheostomy in the immediate postoperative period after total knee arthroplasty in a patient with severe rheumatoid arthritis.
Southern medical journal, 1987
We have described a 39-year-old woman with Maffucci's syndrome, large mediastinal hemangiomas... more We have described a 39-year-old woman with Maffucci's syndrome, large mediastinal hemangiomas, infiltrating adenocarcinoma of the breast, and pituitary adenoma. This is the fifth reported case of Maffucci's syndrome with a coexistent pituitary adenoma, a frequency that cannot be explained by chance alone. There has been only one previously reported case in which the patient had a widened mediastinum, but the etiology was not discussed. Three of the four previously described patients with Maffucci's syndrome and a pituitary adenoma also had a proven or possible associated epithelial neoplasm. While this association is tenuous, it is considered worthy of comment.
Southern Medical Journal, 1990
Medicine & Science in Sports & Exercise, 1994
Three cervical orthoses often used in football to prophylactically limit motion and prevent the n... more Three cervical orthoses often used in football to prophylactically limit motion and prevent the nerve injury known as "burners" were evaluated to determine their performance in limiting both hyperextension and lateral bending of the cervical spine. These orthoses have been used almost entirely on an empiric basis with little objective data to evaluate performance. A rope and pulley mechanism was used to pull the neck into hyperextension and lateral motion, with the only restraint being the various products tested. These trials were videotaped and the restriction provided by the collars was calculated from goniometric analysis of the projected images. These tests were performed to determine which products limit the mechanisms of the "burner" injury and thereby assess which braces might reduce or prevent the occurrence of these injuries. The results of the investigation indicate that all braces studied provided some degree of limitation in one of the mechanisms of injury, hyperextension. One brace performed superiorly in this respect. However, the other mechanism of injury, lateral bending, is inconsistently limited.
Journal of Orthopaedic Research, 1988
A tear of the anterior cruciate ligament (ACL) disrupts the delicate balance of static stabilizer... more A tear of the anterior cruciate ligament (ACL) disrupts the delicate balance of static stabilizers of the knee, leading to significant alterations in joint kinematics. Little is known about the dynamic compensatory responses of the patient to these kinematic alterations. This lack of quantitative information on the muscle synergy patterns has limited the surgeon's ability to evaluate various operative and rehabilitative techniques. Twelve subjects with documented ACL deficiency for at least 1 year and 15 normal participants were studied. Each subject was asked to walk at free and fast speeds on a 12 m walkway. The right and left foot contact patterns and the linear envelopes from the surface electromyogram (EMG) patterns of the gastrocnemius, medial and lateral hamstrings, rectus femoris, and vastus lateralis were measured. Significant differences were found in the muscle synergy patterns during walking. During the swing-to-stance transition, the ACL-deficient subjects showed significantly less activity in the quadriceps and gastrocnemius muscles and more activity in the biceps femoris than in the normal group. During early swing, the vastus lateralis is more active than normal, and during midstance and terminal stance, the hamstrings appear to be less active than normal subjects. These dynamic compensatory mechanisms suggest that use of the hamstring tendons in reconstructive procedures may alter important compensatory mechanisms about the knee joint. Application of dynamic EMG techniques to the study of reconstructive procedures should provide additional information that will assist the clinician in the rational choice of a surgical procedure.
Journal of Orthopaedic Research, 1992
We wished to determine whether anterior cruciate ligament (ACL) injury caused changes in patterns... more We wished to determine whether anterior cruciate ligament (ACL) injury caused changes in patterns of activity of individual or groups of muscles that control the knee joint. The electromyographic (EMG) patterns of six muscles in 26 individuals with uninjured knees and 20 individuals with ruptured ACL were studied during free and fast speed walking. A previously developed clustering technique was used for analysis. This technique involves making the Fourier transform of the average linear envelope (LE) of each muscle for each subject and using the amplitude and phase angles of the lower frequency harmonics as features to describe a pattern. These features are then grouped to subdivide the population of EMG patterns into different types. The results of analyses on single muscles showed that there exists a typical or "normal" pattern for each muscle which most uninjured and some injured subjects exhibit as well as several atypical patterns which mostly injured subjects exhibit, and that the atypical patterns are much more evident at fast walking speed. The characteristics of atypical patterns with respect to normal include time shifts in the peak of major phases of activity, the absence of a second phase of activity, and the existence of additional phases of activity. Synergy analysis showed that if one muscle has an atypical pattern, then several do; i.e., ACL injury induces major changes in the control strategy of the knee. The implications are that for rehabilitation programs one must focus on the training and strengthening of more than one muscle, and that for reconstructive procedures the changes in mechanics of the joint can possibly induce a significant change in its control strategy.
Journal of Orthopaedic Research, 1987
The purpose of this study was to quantitate the blood flow of the anterior cruciate ligament in v... more The purpose of this study was to quantitate the blood flow of the anterior cruciate ligament in vivo. Functional flow was evaluated using laser Doppler flowmetry (LDF), for which the output signal, blood cell flux (BCF), is expressed in terms of volts. Ten patients undergoing routine arthroscopic surgery with clinically intact anterior cruciate ligaments were selected at random for participation in the study. Under arthroscopic visualization, a 2.2-mm probe was placed through a trocar sleeve into the anterior cruciate ligament after the arthroscopic procedure. Pulsatile flow within the ligament was observed in all patients. The mean maximum BCF value ranged from 101 to 274 mV; SD range was +/- 3-9 mV. The mean minimum BCF ranged from 75 to 197 mV; SD range was +/- 0 to 9 mV. Laser Doppler flowmetry offers significant promise as a method for measurement of in vivo anterior cruciate and cruciate substitution blood flow.
Journal of Electromyography and Kinesiology, 1991
Anterior cruciate ligament (ACL) insufficiency and associated rotational instability of the knee ... more Anterior cruciate ligament (ACL) insufficiency and associated rotational instability of the knee joint is a potentially disabling condition. In particular, anterior-posterior laxity increases when the ACL is damaged and decreases with contraction of the hamstring musculature. Because laxity is controllable with muscle activity, comparison of muscular synergy patterns between groups of subjects with ACL-deficient and uninjured knees may identify compensatory mechanisms that could influence therapeutic procedures. All participants selected were between 18 and 40 years of age and had clinical or surgical documentation of ACL deficiency. Each subject was asked to walk and pivot with a stride time of 1 s on a 12-m walkway. The right and left foot-contact patterns and linear envelopes (LE) from the surface electromyographic (EMG) patterns of the gastrocnemius (GS), medial and lateral hamstring, rectus femoris (RF), and vastus lateralis (VL) were measured. Results from 15 subjects with uninjured knees and 12 subjects with ACL-deficient knees showed significant differences between their muscle synergy patterns. The types of differences observed depended on the stride period. All muscles within the ACL-deficient population showed some periods of abnormal activity. The differences in synergies indicate that there is a tendency for a greater net posterior force, flexor moment, and external rotation moment to be produced on the tibia during the time when most external rotation occurs to compensate for the mechanical actions of the lost ligament.
Journal of Electromyography and Kinesiology, 1991
A precise knowledge of the biomechanical alterations produced by anterior cruciate ligament (ACL)... more A precise knowledge of the biomechanical alterations produced by anterior cruciate ligament (ACL) damage would aid in selecting appropriate therapeutic intervention and monitoring rehabilitation. In an attempt to assess dynamic knee joint function, we compared the ground reaction force (GRF) and vertical couple patterns during walking and pivoting from an ACL-deficient population with those from a separate uninjured population. Statistical methods were used to quantitate the differences between the two populations for each force pattern in each functional task and to delineate the intervals of the force patterns in each functional task during which significant differences existed between the two populations. Our results indicate that significant differences exist between the GRF and vertical couple patterns of ACL-deficient subjects and uninjured subjects, but that onset and duration of these differences during stance phase vary among force components and tasks. The processing scheme extracts significant differences in the GRF and vertical couple patterns that would be lost in a comparison of a few pattern descriptors. Our results suggest that the vertical couple should be evaluated during assessment of pivoting maneuvers and show promise of providing useful information for assessment of knee dysfunction.
Journal of Biomechanics, 1987