Biomedical subjects

K P Speer

Publications and source records attributed to K P Speer.

At least 19 recordsLinked to original sources

PubMed2001

Assessment of instability of the long head of the biceps tendon by MRI.

OBJECTIVE: To determine whether MRI can identify instability of the long head of the biceps tendon (LBT) in the rotator interval. DESIGN AND PATIENTS: A retrospective review was carried out of 19 patients, all arthroscopically examined, nine of whom had surgically confirmed instability of the LBT. RESULTS: A LBT perched on the lesser tuberosity correctly indicated all nine cases of instability with one false positive. In six of seven cases where the LBT was oval in shape, no instability of the biceps tendon existed, whereas LBT instability was present in eight of 12 patients with a flat long head of the biceps tendon. In seven of eight acutely angled intertubercular sulci there was no instability of the LBT while eight of 11 obtusely angled sulci were associated with LBT instability. By consensus impression, instability of the LBT could be determined with 67% sensitivity, 90% specificity, 86% positive predictive value, and 75% negative predictive value. CONCLUSIONS: A flat LBT perched on the lesser tuberosity with an obtusely angled intertubercular sulcus suggests the diagnosis of instability of the LBT in the correct clinical setting.

Adult↗

PubMed2001

Anatomy, pathophysiology, and biomechanics of shoulder instability.

Instability in the athlete presents a unique challenge to the orthopaedic surgeon. A spectrum of both static and dynamic pathophysiology, as well as gross and microscopic histopathology, contribute to this complex clinical continuum. Biomechanical studies of the shoulder and ligament cutting studies in recent years have generated a more precise understanding of the individual contributions of the various ligaments and capsular regions to shoulder instability. An understanding of the underlying pathology and accurate assessment of degree and direction of the instability by clinical examination and history are essential to developing appropriate treatment algorithms.

Algorithms↗

PubMed2001

Interscalene brachial plexus block with continuous intraarticular infusion of ropivacaine.

Providing intraarticular analgesia with a continuous infusion of local anesthetic via a disposable infusion pump has gained popularity. Despite the prevalence of this technique, data comparing this method of analgesia to conventional regional anesthesia are not available. We present a prospective study that compared a single-dose interscalene block with a single-dose interscalene block plus continuous intraarticular infusion of local anesthetic. Forty patients scheduled for shoulder arthroscopy were entered in this prospective, double-blinded study. All patients received an interscalene brachial plexus block as their primary anesthetic. Patients were randomly assigned to 1 of 2 groups: 1. interscalene block with 1.5% mepivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.5% ropivacaine at 2 mL/h, or 2. interscalene block with 0.5% ropivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.9% saline (placebo) at 2 mL/h. Postoperative infusions were maintained for 48 h. Visual analog scale pain scores and postoperative oxycodone consumption were measured for 48 h. Visual analog scale scores at rest and with ambulation in the Mepivacaine/Intraarticular Ropivacaine group were reduced when compared with the Ropivacaine/Saline group (rest: P = 0.003, ambulation: P = 0.006). Oxycodone consumption was also decreased (28 +/- 21 mg vs 44 +/- 28 mg, P = 0.046), respectively. We conclude that a brachial plexus block with 1.5% mepivacaine and a continuous intraarticular infusion of 0.5% ropivacaine at 2 mL/h provides improved analgesia for minor surgery at 24 and 48 h versus a single-injection interscalene block with 0.5% ropivacaine.

Adult↗

PubMed2001

Biomechanical analysis of the deadlift during the 1999 Special Olympics World Games.

PURPOSE: Improper lifting techniques may increase injury risks and decrease performance. The aim of this study was to compare and contrast biomechanical parameters between sumo and conventional style deadlifts and between high- and low-skilled lifters who participated in the powerlifting event during the 1999 Special Olympics World Games. METHODS: Two synchronized video cameras collected 60 Hz of data from 40 subjects. Parameters were quantified at barbell liftoff (LO), when the barbell passed the knees (KP), and at lift completion. RESULTS: Compared with the conventional group, the sumo group had a 100% greater stance width, 20% smaller hand width, 10% less vertical bar distance, a more vertical trunk at LO, a more horizontal thigh at LO and KP, a less vertical shank at KP, and greater forefoot abduction. The sumo group generated ankle dorsiflexor, knee extensor, and hip extensor moments, whereas the conventional group produced ankle plantar flexor, knee flexor and extensor, and hip extensor moments. Compared with low-skilled lifters, high-skilled lifters had a 40% greater barbell load, 15% greater stance width (sumo group only), greater knee flexion at LO (conventional group only), greater knee extension at KP, a less vertical shank position at LO (sumo group only), 15% less vertical bar distance, less first peak bar velocity between LO and KP (conventional group only), smaller plantar flexor and hip extensor moment arms at LO and KP, and greater knee extensor moment arms at LO. CONCLUSIONS: The sumo deadlift may be more effective in working ankle dorsiflexors and knee extensors, whereas the conventional deadlift may be more effective in working ankle plantar flexors and knee flexors. High-skilled lifters exhibited better lifting mechanics than low-skilled lifters by keeping the bar closer to the body, which may both enhance performance and minimize injury risk.

Adult↗

PubMed2001

Focal articular cartilage lesions of the superior humeral head: MR imaging findings in seven patients.

OBJECTIVE: We describe the MR imaging findings of focal articular cartilage lesions of the superior humeral head and the clinical features in seven patients. CONCLUSION: Focal articular cartilage lesions of the superior humeral head are rare lesions that may cause clinical symptoms and may be easily overlooked on MR imaging. These lesions occur in a particular location (along the superior surface of the posterior humeral head, medial to the expected location of a Hill-Sachs lesion), are caused by trauma, and do not seem to have a specific mechanism of injury. Because of improvements in MR imaging of cartilage, this area of the shoulder should be inspected for this lesion.

Adolescent↗

PubMed2000

Increased T2 signal intensity in the distal clavicle: incidence and clinical implications.

OBJECTIVE: The objectives of the current study were (1) to quantify the incidence of increased T2 signal in the distal clavicle and (2) to assess the clinical significance of this finding in patients with chronic acromioclavicular (AC) joint pain. DESIGN AND PATIENTS: Eight patients (five male and three female, 15-41 years of age) with disabling shoulder pain localized to the AC joint and marked increased T2 signal in the distal clavicle are presented. These eight patients underwent MR examination over a 25 month period (August 1996 to September 1998). The dictated reports of all shoulder MR examinations conducted over this same time period were reviewed retrospectively for the presence of signal abnormality in the distal clavicle. Clinical data and, in five patients, findings at shoulder arthroscopy or open surgery, were correlated with the results of MR imaging. One patient underwent arthroscopy on both shoulders. RESULTS: The selected eight patients each presented clinically with disabling shoulder pain localized to the AC joint. One patient is presented twice, as both shoulders were symptomatic (n=9). Plain film examination (9/9) failed to indicate a structural cause of shoulder pain in any of the patients. MR examination demonstrated abnormally increased T2 signal in the distal clavicle in all nine cases and no other cause for AC joint pain. Three patients responded to a course of conservative therapy. Six experienced refractory pain despite conservative therapy. Resection of the distal clavicle was performed in five of the six cases. All patients who underwent resection of the distal clavicle experienced complete resolution of AC joint pain. A retrospective review of the dictated reports for all shoulder MR imaging examinations performed at out institution over a 25 month period (August 1996 to September 1998; n=761) demonstrated a 12.5% incidence of abnormally increased T2 signal in the distal clavicle. CONCLUSIONS: Increased T2 signal in the distal clavicle is a relatively common finding (12.5%) on MR imaging examinations of the shoulder and in most cases is of no clinical significance. However, in patients with chronic AC joint pain and no other abnormality on plain film or MR imaging, increased T2 signal may represent an early manifestation of, or a process similar to, osteolysis of the distal clavicle. Patients with this presentation who continue to suffer from disabling pain following conservative therapy may benefit from surgical resection of the distal clavicle.

Acromioclavicular Joint↗

PubMed2000

Magnetic resonance imaging findings in anterolateral impingement of the ankle.

OBJECTIVE: To demonstrate the MR imaging findings of anterolateral impingement (ALI) of the ankle. DESIGN AND PATIENTS: Nine patients with a history of ankle inversion injury and chronic lateral ankle pain were imaged with MR imaging, and the findings correlated with the results of arthroscopy. Three additional patients with clinically suspected ALI of the ankle were also included. Ankle MR imaging studies from 20 control patients in whom ALI was not suspected clinically were examined for similar findings to the patient group. RESULTS: MR imaging findings in the patients with ALI included a soft tissue signal mass in the anterolateral gutter of the ankle in 12 of 12 (100%) cases, corresponding to the synovial hypertrophy and soft tissue mass found at arthroscopy in the nine patients who underwent arthroscopy. Disruption, attenuation, or marked thickening of the anterior talofibular ligament was seen in all cases. Additional findings included signs of synovial hypertrophy elsewhere in the tibiotalar joint in seven of 12 patients (58%) and bony and cartilaginous injuries to the tibiotalar joint in five of 12 (42%). None of the control patients demonstrated MR imaging evidence of a soft tissue mass in the anterolateral gutter. CONCLUSIONS: ALI of the ankle is a common cause for chronic lateral ankle pain. It has been well described in the orthopedic literature but its imaging findings have not been clearly elucidated. The MR imaging findings, along with the appropriate clinical history, can be used to direct arthroscopic examination and subsequent debridement.

Adolescent↗

PubMed2000

The intra-articular component of the subscapularis tendon: anatomic and histological correlation in reference to surgical release in patients with frozen-shoulder syndrome.

Recently, arthroscopic surgical techniques have been reported for release of glenohumeral capsular contractures in selected patients with frozen-shoulder syndrome. The purpose of the current study was to assess the anatomy and histology of the subscapularis muscle, including its intra-articular component. Ten cadaveric shoulders underwent arthroscopy and dissection, and an additional 3 specimens underwent histological analysis. To provide clinical correlation, 35 patients who underwent arthroscopic capsular release completed a modified questionnaire developed by the authors. The anterior-posterior diameter and cephalad-caudad height of the intra-articular subscapularis tendon (IASS) averaged 5 mm and 11 mm, respectively. This represented 83% of the sagittal diameter and 25% of the total height of the subscapularis at the point of release. Histological analysis confirmed these anatomic observations. All patients had reduction of pain and improved function at an average of 22 months after surgery. Only 1 patient had mild subjective symptoms of instability. The current study indicates that the IASS can be released during arthroscopic capsular release for frozen shoulder with minimal risk of secondary anterior instability to the patient.

Aged↗

PubMed2000

Interscalene brachial plexus block with a continuous catheter insertion system and a disposable infusion pump.

Continuous interscalene brachial plexus blockade traditionally requires a hospital stay for local anesthetic infusion, and achieving consistent catheter insertion may be difficult. Incorporating long-acting pain relief from a continuous peripheral nerve block, with a reliable method of catheter insertion, and a self-contained infusion system would be a valuable asset for short-stay care. We compared the efficacy of single injection interscalene brachial plexus blockade to a continuous peripheral nerve block, with an insulated Tuohy system and a disposable infusion pump. Forty adult patients scheduled for open rotator cuff repair were entered in this randomized, double-blinded, placebo-controlled study. Patients received an interscalene brachial plexus blockade and a continuous peripheral nerve catheter as their primary anesthetic and then, were assigned to receive one of two different postoperative infusions: either 0.2% ropivacaine at 10 mL/h via a disposable infusion pump or normal saline at 10 mL/h via a disposable infusion pump (n = 18-20 per group). Visual analog pain scores and postoperative morphine consumption were measured for 24 h. The ropivacaine group showed less pain than the placebo group (P: = 0.0001) between 12 and 24 h after the initial injection of local anesthetic. In addition, initial interscalene blockade was successful in all patients and all redosed catheters were functional after 24 h with the continuous catheter insertion system. We conclude that it is possible to achieve a high rate of successful catheter placement and analgesia by using the continuous catheter insertion system and a disposable infusion pump in the ambulatory setting. This method of analgesia may offer improved pain relief after outpatient rotator cuff repair.

Adolescent↗

PubMed2000

A three-dimensional biomechanical analysis of sumo and conventional style deadlifts.

PURPOSE: Strength athletes often employ the deadlift in their training or rehabilitation regimens. The purpose of this study was to quantify kinematic and kinetic parameters by employing a three-dimensional analysis during sumo and conventional style deadlifts. METHODS: Two 60-Hz video cameras recorded 12 sumo and 12 conventional style lifters during a national powerlifting championship. Parameters were quantified at barbell liftoff (LO), at the instant the barbell passed the knees (KP), and at lift completion. Unpaired t-tests (P < 0.05) were used to compare all parameters. RESULTS: At LO and KP, thigh position was 11-16 degrees more horizontal for the sumo group, whereas the knees and hips extended approximately 12 degrees more for the conventional group. The sumo group had 5-10 degrees greater vertical trunk and thigh positions, employed a wider stance (70 +/- 11 cm vs 32 +/- 8 cm), turned their feet out more (42 +/- 8 vs 14 +/- 6 degrees). and gripped the bar with their hands closer together (47 +/- 4 cm vs 55 +/- 10 cm). Vertical bar distance, mechanical work, and predicted energy expenditure were approximately 25-40% greater in the conventional group. Hip extensor, knee extensor, and ankle dorsiflexor moments were generated for the sumo group, whereas hip extensor, knee extensor, knee flexor, and ankle plantar flexor moments were generated for the conventional group. Ankle and knee moments and moment arms were significantly different between the sumo and conventional groups, whereas hip moments and moments arms did not show any significantly differences. Three-dimensional calculations were more accurate and significantly different than two-dimensional calculations, especially for the sumo deadlift. CONCLUSIONS: Biomechanical differences between sumo and conventional deadlifts result from technique variations between these exercises. Understanding these differences will aid the strength coach or rehabilitation specialist in determining which deadlift style an athlete or patient should employ.

Adult↗

PubMed2000

The MR imaging appearance of longitudinal split tears of the peroneus brevis tendon.

PURPOSE: Longitudinal split tears of the peroneus brevis tendon have been increasingly reported as a source of lateral ankle pain and disability. MR imaging is useful in identifying the appearance of longitudinal split tears of the peroneus brevis tendon to differentiate this entity from other causes of chronic lateral ankle pain. We observed variations in anatomy associated with these tears. MATERIALS AND METHODS: Twenty-two patients (eleven males, eleven females) were identified as having longitudinal split tears of the peroneus brevis tendon. These cases were reviewed retrospectively to evaluate for the following: shape of the peroneus brevis tendon, high signal in the peroneus brevis tendon, tendon subluxation, appearance of the superior peroneal retinaculum, presence of osseous changes in the ankle, lateral ankle ligaments, presence of a bony fibular spur, flattening of the peroneal groove of the fibula and presence of a peroneus quartus. A control group consisted of twenty ankles imaged for reasons other than lateral ankle pain. The same structures were assessed in this group. A Fisher's exact P-value was used to determine the significance of each finding in the two groups. RESULTS: Statistically significant associated findings were chevron shaped tendon (p = .0001), high signal in the peroneus brevis (p = .0017), bony changes (p = .0001), flat peroneal groove (p = .0001), abnormal lateral ligaments (p = .0004), and lateral fibular spur (p = .0006). CONCLUSIONS: MR imaging is useful in differentiating longitudinal split tears of the peroneus brevis tendon from other lateral ankle disorders. It can show the extent of the abnormality in the tendon and the associated findings of soft tissue and/or bone variations which must be addressed at the time of surgery.

Adolescent↗

PubMed2000

The relationship of age, gender, and degenerative changes observed on radiographs of the shoulder in asymptomatic individuals.

Radiographs of the shoulders of 84 asymptomatic individuals aged between 40 and 83 years were evaluated to determine changes in 23 specific areas. Two fellowship-trained orthopaedic radiologists graded each area on a scale of 0 to II (normal 0, mild changes I, advanced changes II). Logistic regression analysis indicated age to be a significant predictor of change (p < 0.05) for sclerosis of the medial acromion and lateral clavicle, the presence of subchondral cysts in the acromion, formation of osteophytes at the inferior acromion and clavicle, and narrowing and degeneration of the acromioclavicular joint. Gender was not a significant predictor (p > 0.05) for radiological changes. Student's t-test determined significance (p < 0.05) between age and the presence of medial acromial and lateral clavicular sclerosis, subchondral acromial cysts, inferior acromial and clavicular osteophytes, and degeneration of the acromioclavicular joint. Radiological analysis in conditions such as subacromial impingement, pathology of the rotator cuff, and acromioclavicular degeneration should be interpreted in the context of the symptoms and normal age-related changes.

Acromioclavicular Joint↗

PubMed2000

Effects of throwing overweight and underweight baseballs on throwing velocity and accuracy.

The purpose of this review is to determine how throwing overweight and underweight baseballs affects baseball throwing velocity and accuracy. Two studies examined how a warm-up with overweight baseballs affected throwing velocity and accuracy of 5 oz regulation baseballs. One of these studies showed significant increases in throwing velocity and accuracy, while the other study found no significant differences. Three training studies (6 to 12 weeks in duration) using overweight baseballs were conducted to determine how they affected ball accuracy while throwing regulation baseballs. No significant differences were found in any study. From these data it is concluded that warming up or training with overweight baseballs does not improve ball accuracy. Seven overweight and 4 underweight training studies (6 to 12 weeks in duration) were conducted to determine how throwing velocity of regulation baseballs was affected due to training with these overweight and underweight baseballs. The overweight baseballs ranged in weight from 5.25 to 17 oz, while the underweight baseballs were between 4 and 4.75 oz. Data from these training studies strongly support the practice of training with overweight and underweight baseballs to increase throwing velocity of regulation baseballs. Since no injuries were reported throughout the training studies, throwing overweight and underweight baseballs may not be more stressful to the throwing arm compared to throwing regulation baseballs. However, since currently there are no injury data related to throwing overweight and underweight baseballs, this should be the focus of subsequent studies. In addition, research should be initiated to determine whether throwing kinematics and kinetics are different between throwing regulation baseballs and throwing overweight and underweight baseballs.

Animals↗

PubMed2000

Shoulder muscle activation during aquatic and dry land exercises in nonimpaired subjects.

STUDY DESIGN: Randomized, single blind experimental design using electromyography to measure shoulder muscle activation in nonimpaired subjects. OBJECTIVES: To compare the muscle activation of rotator cuff and shoulder synergists during rehabilitation exercises performed in water or on dry land. BACKGROUND: Early motion is critical to restoration of normal shoulder function. Aquatic therapy has been promoted as a method for increasing range of motion while minimizing stress on the shoulder. METHODS AND MEASURES: The integrated electromyography amplitude of 6 muscles of the shoulder girdle was examined on the nondominant shoulders of 6 subjects (supraspinatus, infraspinatus, and subscapularis, anterior, middle, and posterior deltoids). Each subject performed elevation (0 degree to 90 degrees) in the scapular plane with neutral rotation on land and in water at 3 different speeds of elevation (30 degrees/s, 45 degrees/s, and 90 degrees/s). The mean percentage of the maximal voluntary contraction was determined for each of the 3 test speeds on land and in water. Comparisons between water and dry land were made with a repeated measures analysis of variance. RESULTS: For all 6 muscles tested, muscle activation during the 30 degrees/s test speed and all muscles tested at the 45 degrees/s test speed was significantly less when performed in water versus when performed on land. For example, electromyography activation of the supraspinatus muscle was 16.68% of a maximal voluntary contraction when elevation at was performed at 30 degrees/s on dry land versus 3.93% when performed in water. CONCLUSION: These data suggest that shoulder elevation in the water at slower speeds resulted in a significantly lower activation of the rotator cuff and synergistic muscles. This decreased muscle activation during aquatic physical therapy allows for earlier active motion in the postoperative period without compromising patient safety.

Adult↗

PubMed1998

A comparison of 0.5% bupivacaine, 0.5% ropivacaine, and 0.75% ropivacaine for interscalene brachial plexus block.

UNLABELLED: The onset time and duration of action of ropivacaine during an interscalene block are not known. The potentially improved safety profile of ropivacaine may allow the use of higher concentrations to try and speed onset time. We compared bupivacaine and ropivacaine to determine the optimal long-acting local anesthetic and concentration for interscalene brachial plexus block. Seventy-five adult patients scheduled for outpatient shoulder surgery under interscalene block were entered into this double-blind, randomized study. Patients were assigned (n = 25 per group) to receive an interscalene block using 30 mL of 0.5% bupivacaine, 0.5% ropivacaine, or 0.75% ropivacaine. All solutions contained fresh epinephrine in a 1:400,000 concentration. At 1-min intervals after local anesthetic injection, patients were assessed to determine loss of shoulder abduction and loss of pinprick in the C5-6 dermatomes. Before discharge, patients were asked to document the time of first oral narcotic use, when incisional discomfort began, and when full sensation returned to the shoulder. The mean onset time of both motor and sensory blockade was <6 min in all groups. Duration of sensory blockade was similar in all groups as defined by the three recovery measures. We conclude that there is no clinically important difference in times to onset and recovery of interscalene block for bupivacaine 0.5%, ropivacaine 0.5%, and ropivacaine 0.75% when injected in equal volumes. IMPLICATIONS: In this study, we demonstrated a similar efficacy between equal concentrations of ropivacaine and bupivacaine. In addition, increasing the concentration of ropivacaine from 0.5% to 0.75% fails to improve the onset or duration of interscalene brachial plexus block.

Adult↗

PubMed1998

Shoulder instability and impingement in throwing athletes.

The glenohumeral articulation maintains a fine balance between mobility and stability. In the throwing athlete, this balance is stressed from the repetitive microtrauma incurred to achieve peak performances. The presentation of shoulder pain in the throwing athlete can be confusing, and a thorough understanding of anatomy and biomechanics, in addition to the history and physical examination, are necessary to delineate the correct diagnosis. Specifically, differentiating between instability and impingement is critical to initiate appropriate nonoperative and operative interventions. This paper discusses the anatomy and biomechanics in the shoulder and provides a comprehensive approach to evaluate anterior shoulder pain in throwing athletes. In addition, treatment options will be discussed with specific emphasis or nonoperative interventions.

Athletic Injuries↗

PubMed1998

Frozen shoulder syndrome: diagnostic and treatment strategies in the primary care setting.

The term "frozen shoulder" has been used to describe an array of clinical conditions. The authors consider a patient as meeting the criteria of primary or secondary frozen shoulder syndrome if he/she has a clinical history of worsening painful shoulder motion loss of at least 1 month duration and a physical examination documenting painful restricted shoulder motion. In the evaluation of the patient with suspected FSS, initial screening shoulder radiographs are required to exclude other conditions. The physical examination of the frozen shoulder patient should include observation, cervical examination, assessment of range of motion, and the use of provocative testing. The treatment of the patient with FSS should include preventative education, various medications including NSAIDS and oral corticosteroids, physical therapy, and finally, for the patient with refractory symptoms, surgical intervention. For those patients necessitating surgical intervention, the authors recommend a selective arthroscopic capsular release.

Arthroscopy↗

PubMed1998

Acute brachial neuritis (Parsonage-Turner syndrome): MR imaging appearance--report of three cases.

Magnetic resonance (MR) imaging findings in three patients with acute onset of neuritic shoulder pain and weakness included high signal intensity in supra- and infraspinatus muscles (n = 2), partial involvement of infraspinatus muscle (n = 1) and of deltoid muscle (n = 1), and atrophy of supra- and infraspinatus muscles (n = 2). Clinical diagnosis of acute brachial neuritis (Parsonage-Turner syndrome) correlated with MR imaging results in all cases.

Acute Disease↗