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Biomedical subjects

F H Fu

Publications and source records attributed to F H Fu.

177 records · Page 10Linked to original sources
PubMedDate not supplied

Rupture of the pectoralis major muscle in a collegiate football player. Use of magnetic resonance imaging in early diagnosis.

We have reported an unusual case of pectoralis major muscle rupture and repair. There were three interesting aspects of this case. First, the injury occurred in a football player with an unusual mechanism of injury. Second, MRI using special techniques was valuable in confirming the diagnosis acutely and in planning treatment. Finally, we reported on the use of suture anchors to secure the avulsed tendon. We recommend the early use of MRI for diagnosis and in planning treatment of suspected pectoralis major muscle ruptures.

Adult↗
PubMedDate not supplied

Quadriceps strength and functional capacity after anterior cruciate ligament reconstruction. Patellar tendon autograft versus allograft.

Harvesting the central third of the patellar tendon for autograft anterior cruciate ligament reconstruction is thought to compromise quadriceps strength and functional capacity. We compared objective measurements of quadriceps strength and functional capacity in athletes after patellar tendon autograft or allograft anterior cruciate ligament reconstruction. We looked at 33 active male patients (mean age, 24.3 years) who had anterior cruciate ligament reconstructions 12 to 24 months earlier using patellar tendon autograft (N = 15) or allograft (N = 18) techniques. All patients underwent an intensive rehabilitation program. Quadriceps strength and power were assessed by measuring peak torque at 60 and 240 deg/sec, torque acceleration energy at 240 deg/sec, and the quadriceps index using a Cybex II isokinetic testing device. Functional capacity was evaluated based on the results of 3 specially designed functional performance tests and the hop test. Results revealed no significant difference between autograft and allograft groups with respect to any of these parameters. These findings indicate that harvesting the central third of the patellar tendon for autograft anterior cruciate ligament reconstruction does not diminish quadriceps strength or functional capacity in highly active patients who have intensive rehabilitation. Thus, the recommendation to avoid patellar tendon autograft anterior cruciate ligament reconstruction to preserve quadriceps strength and functional capacity may be unnecessary.

Adult↗
PubMedDate not supplied

The role of the long head of the biceps muscle and superior glenoid labrum in anterior stability of the shoulder.

The authors conducted a study to determine if the long head of the biceps muscle and its attachment at the superior glenoid labrum play a role in stability of the shoulder in an overhead position. Their study used a dynamic cadaveric shoulder model that simulated the forces of the rotator cuff and long head of biceps muscles as the glenohumeral joint was abducted and externally rotated. Their data suggest that the long head of the biceps muscle contributes to anterior stability of the glenohumeral joint by increasing the shoulder's resistance to torsional forces in the vulnerable abducted and externally rotated position. The biceps muscle also helps to diminish the stress placed on the inferior glenohumeral ligament. Detachment of the superior glenoid labrum is detrimental to anterior shoulder stability as it decreases the shoulder's resistance to torsion and places a greater magnitude of strain on the inferior glenohumeral ligament.

Elasticity↗
PubMedDate not supplied

A biomechanical analysis of rotator cuff deficiency in a cadaveric model.

We conducted this cadaveric study to define a biomechanical rationale for rotator cuff function in several deficiency states. A dynamic shoulder testing apparatus was used to examine change in middle deltoid muscle force and humeral translation associated with simulated rotator cuff tendon paralyses and various sizes of rotator cuff tears. Supraspinatus paralysis resulted in a significant increase (101%) in the middle deltoid force required to initiate abduction. This increase diminished to only 12% for full glenohumeral abduction. The glenohumeral joint maintained ball-and-socket kinematics during glenohumeral abduction in the scapular plane with an intact rotator cuff. No significant alterations in humeral translation occurred with a simulated supraspinatus paralysis, nor with 1-, 3-, and 5-cm rotator cuff tears, provided the infraspinatus tendon was functional. Global tears resulted in an inability to elevate beyond 25 degrees of glenohumeral abduction despite a threefold increase in middle deltoid force. These results validated the importance of the supraspinatus tendon during the initiation of abduction. Glenohumeral joint motion was not affected when the "transverse force couple" (subscapularis, infraspinatus, and teres minor tendons) remained intact. Significant changes in glenohumeral joint motion occurred only if paralysis or anatomic deficiency violated this force couple. Finally, this model confirmed that rotator cuff disease treatment must address function in addition to anatomy.

Aged↗
PubMedDate not supplied

The role of proprioception in the management and rehabilitation of athletic injuries.

Rehabilitation continues to evolve with the increased emphasis on patient management and proprioceptive training. Proprioception can be defined as a specialized variation of the sensory modality of touch that encompasses the sensation of joint movement (kinesthesia) and joint position (joint position sense). Numerous investigators have observed that afferent feedback to the brain and spinal pathways is mediated by skin, articular, and muscle mechanoreceptors. Examining the effects of ligamentous injury, surgical intervention, and proprioceptively mediated activities in the rehabilitation program provides an understanding of the complexity of this system responsible for motor control. It appears that this neuromuscular feedback mechanism becomes interrupted with injury and abnormalities, and approaches restoration after surgical intervention and rehabilitation. Rehabilitation programs should be designed to include a proprioceptive component that addresses the following three levels of motor control: spinal reflexes, cognitive programming, and brainstem activity. Such a program is highly recommended to promote dynamic joint and functional stability. Thus far, current knowledge regarding the basic science and clinical application of proprioception has led the profession of sports medicine one step closer to its ultimate goal of restoring function.

Adaptation, Physiological↗
PubMedDate not supplied

Cervical spine alignment in the immobilized football player. Radiographic analysis before and after helmet removal.

We investigated the effect of football helmet removal on the sagittal alignment of the cervical spine. A quantitative radiographic assessment of relative cervical spine position in subjects immobilized to a standard backboard wearing shoulder pads either with or without a helmet was performed. Comparison was made to a control situation with subjects on a backboard wearing no equipment. Ten subjects were studied using lateral computed tomographic scout films; each subject served as his own control. Radiographs were measured for overall sagittal cervical alignment and the amount of lordosis or kyphosis present within specific segments of the cervical spine. Mean values for each of the three defined situations (no equipment, shoulder pads and helmet, shoulder pads alone after helmet removal) were calculated and subjected to statistical analysis. No statistically significant difference in cervical sagittal alignment was noted when either no equipment or both shoulder pads and helmet were worn. In contrast, a statistically significant increase in cervical lordosis (extension) was found when comparing the control situation to that when only shoulder pads were worn after the helmet had been removed. The majority of this increase occurred in the subaxial spine. Therefore, the authors recommend that football players with a potential cervical spine injury be immobilized for transport with both their helmet and shoulder pads left in place, thereby maintaining the neck in a position most closely approximating "normal."

Adult↗
PubMedDate not supplied

The effects of joint position and direction of joint motion on proprioceptive sensibility in anterior cruciate ligament-deficient athletes.

We studied a group of anterior cruciate ligament-deficient athletes to identify whether joint position and direction of joint motion have a significant effect on proprioception. Twenty-nine anterior cruciate ligament-deficient athletes were tested for their threshold to detect passive motion at both 15 degrees and 45 degrees moving into the directions of both flexion and extension. The single-legged hop test was used to identify function in the deficient limb. Results demonstrated statistically significant deficits in threshold to detect passive motion for the deficient limb at 15 degrees moving into extension. For the deficient limb, threshold to detect passive motion was significantly more sensitive moving into extension than flexion at a starting angle of 15 degrees; at a starting angle of 15 degrees moving into extension threshold was significantly more sensitive than at a starting angle of 45 degrees moving into extension. We conclude that in deficient limbs proprioception is significantly more sensitive in the end ranges of knee extension (15 degrees) and is significantly more sensitive moving into the direction of extension. To effectively restore reflex stabilization of the lower limb we recommend a rehabilitation program emphasizing performance-based, weightbearing, closed kinetic chain exercise for the muscle groups that act on the knee joint.

Adolescent↗
PubMedDate not supplied

Functional evaluation of the ligaments at the acromioclavicular joint during anteroposterior and superoinferior translation.

We examined the anatomy and measured the in situ force in ligaments at the acromioclavicular joint using a universal force-moment sensor. The in situ force in the coracoacromial, conoid, trapezoid, superior acromioclavicular capsular, and inferior acromioclavicular capsular ligaments of 10 fresh-frozen cadaveric shoulders was determined for a load of 70 N applied to the clavicle in anteroposterior and superoinferior directions. The lengths of the conoid and trapezoid ligaments were found to be 15.1 +/- 4.1 and 11.5 +/- 2.2 mm, respectively; the widths of the conoid and trapezoid ligaments were 10.7 +/- 1.5 and 11.0 +/- 2.8 mm, respectively. The in situ force of the trapezoid (42.9 +/- 15.4 N) was significantly greater than that for the other ligaments during posterior displacement. Otherwise, no statistically significant differences could be found between any of the in situ forces in each ligament during all other motions examined. During anterior displacement, the inferior acromioclavicular capsular ligament appeared to be the major restraint. The trapezoid ligament was the primary restraint during posterior displacement and provided 55.8% +/- 20.0% of the resisting force. Our results suggest that the coracoclavicular and other acromioclavicular joint capsular ligaments should be considered for reconstruction to restore normal joint function, especially in the anterior, posterior, and superior directions.

Acromioclavicular Joint↗
PubMedDate not supplied

Suturing versus immobilization of a muscle laceration. A morphological and functional study in a mouse model.

Muscle laceration remains a difficult problem for orthopaedic surgeons. Despite many studies related to the muscle's ability to regenerate after muscle degeneration, very few reports are available regarding structural and functional recovery after skeletal muscle laceration. We developed an animal model of muscle laceration in mice, where the gastrocnemius muscles were reproducibly transected. We compared the effect of a surgical repair versus a short period of immobilization (5 days) on the muscle healing. The natural course of muscle recovery was monitored at several points after injury using histologic, immunohistochemical, and functional testing. In the injured muscle, we observed a high number of regenerating myofibers and development of fibrotic scar tissue. Suturing the lacerated muscle immediately after injury promoted better healing of the injured muscle and prevented the development of deep scar tissue in the lacerated muscle; conversely, immobilization resulted in slower muscle regeneration and the development of a large area of scar tissue. Tetanus strength 1 month after injury was 81% of control muscles for the sutured muscles, 35% for the lacerated muscles with no treatment, and 18% for the immobilized muscles. Based on this study, suturing a muscle laceration with a modified Kessler stitch results in the best morphologic and functional healing.

Analysis of Variance↗
PubMedDate not supplied

Knee joint laxity and neuromuscular characteristics of male and female soccer and basketball players.

Anterior cruciate ligament injuries are occurring at a higher rate in female athletes compared with their male counterparts. Research in the area of anterior cruciate ligament injury has increasingly focused on the role of joint proprioception and muscle activity in promoting knee joint stability. We measured knee joint laxity, joint kinesthesia, lower extremity balance, the amount of time required to generate peak torque of the knee flexor and extensor musculature, and electromyographically assessed muscle activity in 34 healthy, collegiate-level athletes (average age, 19.6 +/- 1.5 years) who played soccer or basketball or both. Independent t-tests were used to determine significant sex differences. Results revealed that women inherently possess significantly greater knee joint laxity values, demonstrate a significantly longer time to detect the knee joint motion moving into extension, possess significantly superior single-legged balance ability, and produce significantly greater electromyographic peak amplitude and area of the lateral hamstring muscle subsequent to landing a jump. The excessive joint laxity of women appears to contribute to diminished joint proprioception, rendering the knee less sensitive to potentially damaging forces and possibly at risk for injury. Unable to rely on ligamentous structures, healthy female athletes appear to have adopted compensatory mechanisms of increased hamstring activity to achieve functional joint stabilization.

Adult↗
PubMedDate not supplied

Current trends in anterior cruciate ligament reconstruction. Part 1: Biology and biomechanics of reconstruction.

With today's increasing emphasis on sporting activities, the incidence of anterior cruciate ligament injuries has also increased. Epidemiologic studies estimate that the prevalence of anterior cruciate ligament injuries is about 1 per 3000 Americans. Management of these injuries has evolved from nonoperative treatment to extracapsular augmentation and primary ligament repair to anterior cruciate ligament reconstruction. Treatment of these injuries has significantly improved over the last few decades with the application of knowledge gained from both basic science and clinical research. This article is composed of two parts. The first part reviews the biology and biomechanics of the injured anterior cruciate ligament and the basic science of reconstruction. In the second part, to be published later, current operative concepts of reconstruction, as well as clinical correlations, are reviewed. Summarizing the latest information on basic scientific as well as clinical studies regarding the anterior cruciate ligament, this article intends to demonstrate the correlation between the application of basic science knowledge and improvement of clinical outcomes.

Anterior Cruciate Ligament↗
PubMedDate not supplied

Development of approaches to improve the healing following muscle contusion.

Muscle injuries are a challenging problem in traumatology, and the most frequent occurrence in sports medicine. Muscle contusions are among the most common muscle injuries. Although this injury is capable of healing, an incomplete functional recovery often occurs, depending on the severity of the blunt trauma. We have developed an animal model of muscle contusion in mice (high energy blunt trauma) and characterized the muscle's ability to heal following this injury using histology and immunohistochemistry to determine the level of muscle regeneration and the development of scar tissue. We have observed a massive muscle regeneration occurring in the first 2 wk postinjury that is subsequently followed by the development of muscle fibrosis. Based on these observations, we propose that the enhancement of muscle growth and regeneration, as well as the prevention of fibrotic development, could be used as approach(es) to improve the healing of muscle injuries. In fact, we have identified three growth factors (bFGF, IGF-1, and NGF) capable of enhancing myoblast proliferation and differentiation in vitro and improving the healing of the injured muscle in vivo. Furthermore, the ability of adenovirus to mediate direct and ex vivo gene transfer of beta-galactosidase into the injured site opens possibilities of delivering an efficient and persistent expression of these growth factors in the injured muscle. These studies should help in the development of strategies to promote efficient muscle healing with complete functional recovery following muscle contusion.

Animals↗
PubMedDate not supplied

Combined Maquet and proximal tibial valgus osteotomy.

A combined Maquet and proximal tibial valgus osteotomy has been used to treat patients presenting with anterior and medial compartmental degenerative arthritis. Patients with clinically symptomatic lateral compartmental disease, gross instability, or a nonfunctional range of motion were excluded. Thirty-four knees in 31 patients whose average age was 59.6 years were studied. Follow-up periods range from six to 36 months (mean, 16 months). Results have been tabulated with respect to the patient's preoperative radiographs and clinical knee ratings. The surgical technique has been the same throughout the series and is notable for the absence of metallic fixation and for the division of the tibiofibular joint proximally without an associated fibular osteotomy. Neither nonunion nor peroneal nerve dysfunction was encountered postoperation. To date, 68% of the results have been graded as good to excellent, 20% as fair, and 12% have failed. No correlation was found between preoperative radiographic rating and postoperative result.

Adult↗
PubMedDate not supplied

A comparison of the posterolateral and anterolateral approaches to total hip arthroplasty.

A comparative statistical analysis was performed weighing the relative merits of two surgical approaches for total hip arthroplasty--the Watson-Jones anterolateral approach and the gluteus maximus splitting posterolateral approach. Intraoperative and clinical records were evaluated for 175 patients undergoing total hip arthroplasty between 1975 and 1979--100 by a posterolateral approach and 75 by an anterolateral approach. Minimum follow-up period was two years. Mean operative times for the posterolateral and anterolateral approaches were 62 minutes and 140 minutes, respectively. The posterolateral group had a mean blood loss of 433 ml, with 35% requiring an average transfusion of 2.5 units. The anterolateral group had a mean blood loss of 767 ml, with 78% requiring an average transfusion of 2.5 units. The average lengths of hospitalization for posterolateral and anterolateral groups were 13 and 15 days, respectively. The time to independent cane ambulation was significantly less in the posterolateral group. The rate of post-operative complications was similar in each group. However, in the posterolateral group there were four dislocations, three loosened femoral components, one deep-wound infection, and one pulmonary embolus, while the anterolateral group suffered one dislocation, no prosthesis loosening, no deep-wound infections, and three pulmonary emboli. Although the posterolateral approach was associated with a lower perioperative morbidity than the anterolateral approach, the latter exhibited fewer dislocations and loosened acetabular components.

Adolescent↗