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Biomedical subjects

Claude T Moorman

Publications and source records attributed to Claude T Moorman.

At least 19 recordsLinked to original sources

Tunnel convergence in combined anterior cruciate ligament and posterolateral corner reconstruction.

PURPOSE: To examine the geometric relationship between tunnels created in the lateral femoral condyle in reconstruction of the anterior cruciate ligament (ACL) and the posterolateral structures. METHODS: The geometric relationship between a standard ACL tunnel and 11 lateral femoral tunnel variations in synthetic femur specimens was examined. Tunnel collision frequency and tunnel separation were measured radiographically. Subsequent evaluation was performed on 7 paired cadaveric specimens (14 knees) to access the efficacy of 2 configurations. RESULTS: Phase I-Tunnel collision frequency was 0% and 58% for 25-mm and 30-mm tunnel depths, respectively. Axial angles greater than 40 degrees and coronal angles > or =20 degrees resulted in unsafe configurations. The safest position for lateral tunnel placement was straight lateral approach (0 degrees in the coronal plane) with increased axial plane orientation (hand dropped toward the floor 40 degrees). The safe zone for lateral tunnel configuration was determined to be between [0,0] and [0,40] ([coronal, axial]). Phase II--Control group ([0,0]) collision frequencies were 43% and 86% for the 25-mm 30-mm tunnels, respectively. Experimental group ([0,40]) collision frequencies were 29% and 43% for the 25-mm and 30-mm tunnel, respectively. In femoral condyles measuring <35 mm, collision rates were 100% versus 0% in the control group ([0,0]) versus the experimental group ([0,40]). In specimens where no collision was seen, tunnel separation distance was 4.5 +/- 4.4 mm and 5.8 +/- 2.2 mm for the control and experimental groups, respectively (P = .39). CONCLUSIONS: Tunnel collision occurred often. Tunnel collision is dependent on femoral condyle geometry, tunnel depth, and tunnel configuration. To minimize the potential for tunnel collision, the surgeon should maintain a neutral alignment in the coronal plane, limit lateral tunnel depth to < or =25 mm, and direct the lateral tunnel anteriorly in the axial plane to a maximum of 40 degrees. CLINICAL RELEVANCE: This study describes guidelines for tunnel placement to prevent tunnel collision when performing combined ACL and posterolateral corner reconstruction.

Anterior Cruciate Ligament↗

An anatomic study of the cephalic vein in the deltopectoral shoulder approach.

There has been debate regarding medial or lateral retraction of the cephalic vein in the deltopectoral approach to the shoulder. Those who recommend lateral retraction of the vein cite multiple feeder vessels from the deltoid muscle; however, there is little evidence to support this in the orthopaedic literature. The purpose of our study was to determine if there are more lateral branches than medial branches to the cephalic vein in the deltopectoral groove. Forty fresh frozen cadaveric shoulders underwent retrograde latex injection of the cephalic vein. A deltopectoral incision was used, and the numbers of medial and lateral branches were recorded. In the deltopectoral groove there were more lateral than medial feeder vessels to the cephalic vein. There also were more branches to the vein in the proximal (1/2) of the incision compared with the distal (1/2). Most of the specimens dissected had more lateral branches to the cephalic vein than medial branches. Based on the number of feeder vessels to the cephalic vein, results of our study support lateral retraction of the cephalic vein in a majority of shoulders during the deltopectoral approach to the shoulder.

Adult↗

Spinal injuries in contact sports.

Contact and collision sports such as American football expose the athlete to a wide array of potential injuries. Knee injuries garner much of the attention, but spinal injuries are potentially catastrophic and all levels of medical coverage of football must be knowledgeable and prepared to attend to an athlete with a neck injury. Of the other possible spinal conditions, some resolve on their own, others might require conservative therapy, and still others might require surgical intervention. The spectrum of potential injury is wide, yet the medical team must practice and prepare to treat the possible catastrophic neck injury.

Athletic Injuries↗

An electromyographic analysis of commercial and common abdominal exercises: implications for rehabilitation and training.

STUDY DESIGN: A repeated-measures, counterbalanced design. OBJECTIVES: To test the effectiveness of 7 commercial abdominal machines (Ab Slide, Ab Twister, Ab Rocker, Ab Roller, Ab Doer, Torso Track, SAM) and 2 common abdominal exercises (crunch, bent-knee sit-up) on activating abdominal and extraneous (nonabdominal) musculature. BACKGROUND: Numerous abdominal machine exercises are believed to be effective in activating abdominal musculature and minimizing low back stress, but there are minimal data to substantiate these claims. Many of these exercises also activate nonabdominal musculature, which may or may not be beneficial. METHODS AND MEASURES: A convenience sample of 14 subjects performed 5 repetitions for each exercise. Electromyographic (EMG) data were recorded for upper and lower rectus abdominis, external and internal oblique, pectoralis major, triceps brachii, latissimus dorsi, lumbar paraspinals, and rectus femoris, and then normalized by maximum muscle contractions. RESULTS: Upper and lower rectus abdominis EMG activities were greatest for the Ab Slide, Torso Track, crunch, and Ab Roller, while external and internal oblique EMG activities were greatest for the Ab Slide, Torso Track, crunch, and bent-knee sit-up. Pectoralis major, triceps brachii, and latissimus dorsi EMG activities were greatest for the Ab Slide and Torso Track. Lumbar paraspinal EMG activities were greatest for the Ab Doer, while rectus femoris EMG activities were greatest for the bent-knee sit-up, SAM, Ab Twister, Ab Rocker, and Ab Doer. CONCLUSIONS: The Ab Slide and Torso Track were the most effective exercises in activating abdominal and upper extremity muscles while minimizing low back and rectus femoris (hip flexion) activity. The Ab Doer, Ab Twister, Ab Rocker, SAM, and bent-knee sit-up may be problematic for individuals with low back pathologies due to relatively high rectus femoris activity.

Abdominal Muscles↗

Surgical management of anterior cruciate ligament injuries in patients with open physes.

Because of the increasing number of skeletally immature athletes who compete in highly demanding sports, more children than previously are sustaining anterior cruciate ligament injuries. Treatment and patient compliance with treatment recommendations are problematic. Pediatric issues include those specific to evaluation, projected growth, and surgery. Strict activity modification can protect the knee from further injury and delay surgery, sometimes until maturity. Surgical options include physeal-sparing, partial transphyseal, and complete transphyseal procedures. Surgical procedures are demanding because typical drilling and fixation techniques can affect the physis and possibly lead to growth disturbances. A wide range of growth disturbances has been reported; these must be understood to perfect surgical technique and avoid potential growth concerns. Surgical challenges, options regarding delayed surgery, and possible outcomes all need to be clearly communicated to the patient and parents.

Anterior Cruciate Ligament↗

Rotator cuff injuries in the contact athlete.

Rotator cuff injuries in contact athletes are typically a result of a different mechanism than that seen with older patients or overhead athletes. This unique mechanism along with the extreme demands of these athletes presents special challenges to the surgeon. Special consideration should be given to in-season rehabilitation to allow the athlete to continue to compete if possible. When this is not possible, or for the out-of-season athlete with a rotator cuff injury requiring surgery, special consideration must be given to obtaining the strongest repair possible. The goal in all aspects of treatment is returning the athlete to full participation safely while minimizing recurrent injury or disability during the recovery process.

Arthroscopy↗

Technique for arthroscopic rotator cuff repair.

Modern arthroscopic tools and techniques have allowed surgeons to operate on a wide variety of injuries using procedures less invasive than traditional open methods. For shoulder surgery in general, and rotator cuff repairs specifically, methods now yield a similar footprint as open procedures with several advantages, including reduced tissue trauma, postoperative pain, swelling, and concern about the deltoid attachment, which should lead to good outcomes.

Arthroscopy↗

Fifth metatarsal stress fractures in elite basketball players: evaluation of forces acting on the fifth metatarsal.

Our hypothesis in this study was that significant forces act on the fifth metatarsal during certain maneuvers commonly performed while playing basketball and that medial arch support influences these forces. Eleven male collegiate basketball players participated in this study. Electronic pressure sensors capable of dynamic readings were inserted into the players' shoes, and surface electromyographic (EMG) electrodes were placed over the peroneus longus and brevis muscles. The players performed 3 common maneuvers postulated to place maximal stress on the fifth metatarsal. The maneuvers were performed in a standard basketball shoe, then in a shoe with an orthosis supporting the arch. During each of these maneuvers, EMG activity of the ankle everters was recorded, along with maximal force, total work, and time elapsed beneath the fifth metatarsal.

Basketball↗

The contribution of contractile pre-activation to loss of function after a single lengthening contraction.

PURPOSE: Some muscle injuries are the result of a single lengthening contraction. Our goal was to evaluate the contributions of angular velocity, arc of motion, and timing of contractile activation relative to the onset of joint motion in an animal model of muscle injury using a single lengthening contraction. METHODS: The intact tibialis anterior (TA) muscle of rats was activated while lengthened, preceded by a maximal isometric contraction of 0, 25, 50, 100, or 200 ms. The lengthening contraction was performed at two different angular velocities (300 or 900 degrees/s) and through two different arcs of motion (90 degrees or 45 degrees). RESULTS: Muscle contractile function, as measured by maximal isometric tetanic tension, was significantly decreased only when the TA was activated at least 50 ms prior to the motion, regardless of angular velocity or arc of motion. CONCLUSION: The data indicated that the duration of an isometric contraction prior to a single lengthening contraction determined the extent of muscle injury irrespective of two different angular velocities.

Animals↗

Dexamethasone and recovery of contractile tension after a muscle injury.

Muscle strains, frequently the result of a lengthening contraction, sometimes are treated with corticosteroids. We tested whether an injection of dexamethasone administered soon after muscle injury would minimize inflammation and facilitate the recovery of contractile tension. We applied one eccentric contraction on the tibialis anterior of 76 rats, which were randomly assigned to one of three groups: sham-injured plus dexamethasone, injured plus vehicle, and injured plus dexamethasone. Electrophysiology, histology, and reverse transcription-polymerase chain reaction were used to study the relation between contractile tension, inflammation, and the expression of inflammatory molecules. The single eccentric contraction led to a reversible muscle injury characterized initially by reduced contractile tension and inflammation. The dexamethasone injection reduced the expression of interleukin-1beta and transforming growth factor-beta1 compared with injured vehicle-injected controls and led to a transient improvement of contractile tension 3 days after the injury. No adverse effects were seen for as much as 3 weeks after the dexamethasone injection. The data indicate that one dose of dexamethasone administered soon after muscle strain may facilitate recovery of contractile tension without causing major adverse consequences in this experimental model.

Animals↗

Hyperconcavity of the lumbar vertebral endplates in the elite football lineman.

BACKGROUND: Hyperconcavity of the vertebral endplates is a previously unreported radiologic phenomenon. PURPOSE: To analyze hyperconcavity of the vertebral endplates with expansion of the disk space in pre-National Football League lineman and to determine its clinical significance. STUDY DESIGN: Descriptive anatomical study. METHODS: Over a 2-year period (1992-1993), 266 elite football linemen were evaluated at the National Football League scouting combine held in Indianapolis, Indiana. Evaluation focused on the lumbosacral spine and included history, physical examination, and lateral radiographs. Measurements were taken of all the vertebral endplate defects of involved vertebrae and compared with an age-matched control group of 110 patients. RESULTS: The analyzed data revealed the following: (1) hyperconcavity of the vertebral endplates appeared as a distinct entity in a high percentage of pre-National Football League lineman (33%) compared with age-matched controls (8%), (2) there was a trend toward a lower incidence of lumbosacral spine symptoms in those players who displayed hyperconcavity of the vertebral endplates (16%) versus those who did not (25%), and (3) when hyperconcavity of the vertebral endplates was present, all 5 lumbosacral disk spaces were commonly affected. CONCLUSIONS: Hyperconcavity of the vertebral endplates and hypertrophy of the disk space are likely adaptive changes occurring over time in response to the repetitive high loading and axial stress experienced in football line play.

Adaptation, Physiological↗

The effect of oblique femoral tunnel placement on rotational constraint of the knee reconstructed using patellar tendon autografts.

PURPOSE: Despite the high long-term success rates of anterior cruciate ligament (ACL) reconstructions, 8% of patients undergoing this primary procedure have recurrent disability and graft failure. Nonanatomic tunnel positioning (primarily of the femoral tunnel) accounts for most of all technical failures. We hypothesized that reconstructions that closely recreate the oblique femoral attachment of the ACL would result in more normal knee rotational stability than more vertical reconstruction. The purpose of this study was to determine whether obliquity of the femoral tunnel in the coronal (frontal) plane has an effect on rotational constraint after ACL reconstruction, as measured by anterior tibial translation, external rotation, and internal rotation. TYPE OF STUDY: Ex vivo biomechanical study. METHODS: Ten matched pairs of fresh-frozen cadaver knees were alternately assigned to a standard or an oblique tunnel position reconstruction. Each knee was tested at 30 degrees and 90 degrees of flexion on a materials testing machine in ACL-intact, ACL-sectioned, and ACL-reconstructed states. A 100-N load was applied at a rate of 10 N/second, and anterior tibial translation was measured. Then 6.5 Nm of torque were applied, and external tibial rotation and internal tibial rotation were measured. The effects of tunnel placement and ligament condition were analyzed with a repeated measures analysis of variance. Significance was set at P < or =.05 (Tukey's test). RESULTS: At 30 degrees of flexion, internal tibial rotation in oblique reconstruction was restored to intact values and was significantly less than the internal tibial rotation values in standard reconstruction. Internal tibial rotation in standard reconstruction was significantly greater than intact values. No significant differences were found between standard and oblique tunnel reconstructions and the respective intact values for the remaining internal tibial rotation and all external tibial rotation tests, regardless of flexion angle. CONCLUSIONS: In our biomechanical model, ACL reconstructions using oblique femoral tunnels restored normal knee kinematics.

Aged↗

The role of arteriography in assessing popliteal artery injury in knee dislocations.

BACKGROUND: This study aimed to review the need for angiography among patients with traumatic knee dislocations, and to evaluate any adverse consequences associated with the clinical decision to pursue or defer angiography. METHODS: A retrospective analysis was performed for 55 patients (57 knees) with traumatic knee dislocation during a 7-year period. The presence or absence of arterial injury was assessed via physical examination (to determine presence of foot pulses and ankle-brachial index > or = 0.80) and, in selected cases, via angiography. RESULTS: At the vascular examination, 32 knees (56%) were found to be normal and 25 (44%) to be abnormal. None of the 32 knees with normal examination results had substantial vascular injuries, as determined by angiography in 13 cases (41%) or by clinical follow-up assessment in 19 cases (59%). All 25 patients with abnormal vascular examination results underwent angiography, with 12 patients (48%) demonstrating vascular injury (7 major and 5 minor injury). Seven patients (6 with major and 1 with minor injury) underwent surgical repair with reverse saphenous vein grafting. CONCLUSIONS: No limb with initial normal vascular examination results was found to have a vascular injury that required treatment. Routine screening angiography may not be necessary for all patients with traumatic knee dislocations.

Adolescent↗

Anterior cruciate ligament injuries in children with open physes: evolving strategies of treatment.

Injury to the anterior cruciate ligament is one of the most common sports-related injuries of the knee. Before the 1980s, the incidence of this injury in skeletally immature patients was thought to be rare. However, with the increasing participation of children in sports-related activities and an increased awareness and diagnostic capability of the medical community, midsubstance tears of the anterior cruciate ligament have become more common in patients with open physes. Significant controversy exists regarding management of anterior cruciate ligament injuries in children with open physes. Traditional management has been nonoperative, consisting of physical therapy, bracing, and activity modification. Surgical reconstruction has generally been postponed until the patient is nearing, or has reached, skeletal maturity. In contrast to this traditional treatment algorithm, the recent literature uniformly indicates that nonoperative management of anterior cruciate ligament tears in children results in less than optimal results. Compliance is certainly an issue, and even though patients may refrain from organized sports activities, they are still going to be "kids." Recurrent instability, pain, and an inability to return to the preinjury level of athletics often result. Even more worrisome are the risks of secondary meniscal tears and the possibility of early degenerative joint disease. Recently, there has been an increased interest in early, aggressive operative management to restore stability to the immature knee. Proponents of nonoperative treatment point to the risk of growth arrest associated with violation of the physis. Proponents of early operative stabilization advocate that restoration of stability provides for opportunity to return to full activity and provides good long-term outcomes, all with minimal risk to the physis. This article reviews both the basic science and clinical research on this controversial topic.

Anterior Cruciate Ligament↗

Use of autograft quadriceps tendon for double-bundle posterior cruciate ligament reconstruction.

Many graft choices are available for the reconstruction of the posterior cruciate ligament (PCL)-deficient knee. These choices range from multiple autograft and allograft sources. Preoperative planning must take into account the viability of knee autografts and the availability of allografts. The nature of the PCL injury must also be taken into account, such as whether only the PCL is deficient or the PCL lesion is part of a complex multiple ligament-injured knee. Our institution has begun to use the central quadriceps tendon bone autograph for multiple types of PCL reconstructions. This paper discusses the surgical techniques used to harvest and secure a double-bundle central quadriceps tendon bone autograph for PCL reconstructions using both open and arthroscopic approaches.

Braces↗

Traumatic posterior hip subluxation in American football.

BACKGROUND: Traumatic posterior hip subluxation is a potentially devastating injury that is often misdiagnosed as a simple hip sprain or strain. The purpose of the present study was to outline the injury mechanism, pathoanatomy, clinical and radiographic findings, and treatment of traumatic hip subluxation in an athletic population. METHODS: Over a nine-year period, eight participants in American football who had sustained a traumatic posterior hip subluxation were evaluated and treated. The injury mechanism, clinical findings, and radiographic findings were reviewed. The mean duration of follow-up was thirty-four months. RESULTS: The most common mechanism of injury was a fall on a flexed, adducted hip. Physical examination revealed painful limitation of hip motion. Initial radiographs demonstrated a characteristic posterior acetabular lip fracture. Initial magnetic resonance images revealed disruption of the iliofemoral ligament, hemarthrosis, and a viable femoral head. Two players were treated acutely with hip aspiration, and all eight players were treated with a six-week regimen of toe-touch weight-bearing with use of crutches. Six players recovered and returned to the previous level of competition. Two players had development of severe osteonecrosis and ultimately required total hip arthroplasty. CONCLUSION: The pathognomonic radiographic and magnetic resonance imaging triad of posterior acetabular lip fracture, iliofemoral ligament disruption, and hemarthrosis defines traumatic posterior hip subluxation. Patients in whom large hemarthroses are diagnosed on magnetic resonance images should undergo acute aspiration, and all players should be treated with a six-week regimen of toe-touch weight-bearing with use of crutches. Patients who have no sign of osteonecrosis on magnetic resonance imaging at six weeks can safely return to sports activity. Patients in whom osteonecrosis is diagnosed at six weeks are at risk for collapse and joint degeneration, and they should be advised against returning to sports.

Accidental Falls↗