Stephen Lyman

Osseous Adaptation and Range of Motion at the Glenohumeral Joint in Professional Baseball Pitchers

The throwing shoulder in pitchers frequently exhibits a paradox of glenohumeral joint motion, in which excessive external rotation is present at the expense of decreased internal rotation. The object of this study was to determine the role of humeral head retroversion in relation to increased glenohumeral external rotation. Glenohumeral joint range of motion and laxity along with humeral head and glenoid version of the dominant versus nondominant shoulders were studied in 25 professional pitchers and 25 nonthrowing subjects. Each subject underwent a computed tomography scan to determine bilateral humeral head and glenoid version. The throwing group demonstrated a significant increase in the dominant shoulder versus the nondominant shoulder in humeral head retroversion, glenoid retroversion, external rotation at 90°, and external rotation in the scapular plane. Internal rotation was decreased in the dominant shoulder. Total range of motion, anterior glenohumeral laxity, and posterior glenohumeral laxity were found to be equal bilaterally. The nonthrowing group demonstrated no significant difference in humeral head retroversion, glenoid retroversion, external rotation at 90° or external rotation in the scapular plane between shoulders, and no difference in internal rotation at 90°, total motion, or laxity. A comparison of the dominant shoulders of the two groups indicated that both external rotation at 90° and humeral head retroversion were significantly greater in the throwing group.

Effect of Pitch Type, Pitch Count, and Pitching Mechanics on Risk of Elbow and Shoulder Pain in Youth Baseball Pitchers

Background Joint pain is thought to be an early sign of injury to a pitcher. Objective To evaluate the association between pitch counts, pitch types, and pitching mechanics and shoulder and elbow pain in young pitchers. Study Design Prospective cohort study. Methods Four hundred and seventy-six young (ages 9 to 14 years) baseball pitchers were followed for one season. Data were collected from pre- and postseason questionnaires, injury and performance interviews after each game, pitch count logs, and video analysis of pitching mechanics. Generalized estimating equations and logistic regression analysis were used. Results Half of the subjects experienced elbow or shoulder pain during the season. The curveball was associated with a 52% increased risk of shoulder pain and the slider was associated with an 86% increased risk of elbow pain. There was a significant association between the number of pitches thrown in a game and during the season and the rate of elbow pain and shoulder pain. Conclusions Pitchers in this age group should be cautioned about throwing breaking pitches (curveballs and sliders) because of the increased risk of elbow and shoulder pain. Limitations on pitches thrown in a game and in a season can also reduce the risk of pain. Further evaluation of pain and pitching mechanics is necessary.

Longitudinal study of elbow and shoulder pain in youth baseball pitchers.

PURPOSE Previous studies among young pitchers have focused on the frequency and description of elbow injuries. The purpose of this study was to evaluate the frequency of elbow and shoulder complaints in young pitchers and to identify the associations between pitch types, pitch volume, and other risk factors for these conditions. METHODS A prospective cohort study of 298 youth pitchers was conducted over two seasons. Each participant was contacted via telephone after each game pitched to identify arm complaints. Generalized estimating equations were used to assess associations between arm complaints and independent variables. RESULTS The frequency of elbow pain was 26%; that of shoulder pain, 32%. Risk factors for elbow pain were increased age, increased weight, decreased height, lifting weights during the season, playing baseball outside the league, decreased self-satisfaction, arm fatigue during the game pitched, and throwing fewer than 300 or more than 600 pitches during the season. Risk factors for shoulder pain included decreased satisfaction, arm fatigue during the game pitched, throwing more than 75 pitches in a game, and throwing fewer than 300 pitches during the season. CONCLUSION Arm complaints are common, with nearly half of the subjects reporting pain. The factors associated with elbow and shoulder pain were different, suggesting differing etiologies. Developmental factors may be important in both. To lower the risk of pain at both locations, young pitchers probably should not throw more than 75 pitches in a game. Other recommendations are to remove pitchers from a game if they demonstrate arm fatigue and limit pitching in nonleague games.

Older driver involvements in police reported crashes and fatal crashes: trends and projections

Objectives: Older drivers have become a larger part of the driving population and will continue to do so as the baby boomers reach retirement age. The purpose of this study was to identify the potential effects of this population increase on highway safety. Methods: Driver involvement rates for all police reported crashes were calculated per capita, per licensed driver, and per vehicle-mile of travel for 1990 and 1995. Also, driver involvement rates for fatal crashes were calculated for 1983, 1990, and 1995. Based on current crash rates per licensed driver and estimates of the future number of licensed drivers, projections of crashes involving drivers aged 65 and older were made for years 2010, 2020, and 2030. Results: Driver crash involvement rates per capita decreased with age, but fatal involvement rates per capita increased starting at age 70. The same pattern existed for involvement rates per licensed driver. For both all crashes and fatal crashes, involvement rates per mile driven increased appreciably at age 70. Using projections of population growth, it was estimated that for all ages there will be a 34% increase in the number of drivers involved in police reported crashes and a 39% increase in the number involved in fatal crashes between 1999 and 2030. In contrast, among older drivers, police reported crash involvements are expected to increase by 178% and fatal involvements may increase by 155% by 2030. Drivers aged 65 and older will account for more than half of the total increase in fatal crashes and about 40% of the expected increase in all crash involvements; they are expected to account for as much as 25% of total driver fatalities in 2030, compared with 14% presently. Conclusions: By most measures, older drivers are at less risk of being involved in police reported crashes but at higher risk of being in fatal crashes. Although any projections of future crash counts have inherent uncertainty, there is strong evidence that older drivers will make up a substantially larger proportion of drivers involved in fatal crashes by 2030 because of future increases in the proportion of the population aged 65 and older, and trends toward increased licensure rates and higher annual mileage among older persons. Countermeasures to reduce the anticipated death toll among older drivers should address the increased susceptibility to injury of older vehicle occupants in crashes.

Epidemiology of Anterior Cruciate Ligament Reconstruction: Trends, Readmissions, and Subsequent Knee Surgery

BACKGROUND Anterior cruciate ligament reconstruction is widely accepted as the treatment of choice for individuals with functional instability due to anterior cruciate deficiency. There remains little information on the epidemiology of anterior cruciate ligament reconstruction with regard to adverse outcomes such as hospital readmission and subsequent knee surgery. We sought to identify the frequency of anterior cruciate ligament reconstruction, the rates of subsequent operations and readmissions, and potential predictors of these outcomes. METHODS The Statewide Planning and Research Cooperative System (SPARCS) database, a census of all hospital admissions and ambulatory surgery in New York State, was used to identify anterior cruciate ligament reconstructions performed between 1997 and 2006. Patients with concomitant pathological conditions of the knee were included. The patients were tracked for hospital readmission within ninety days after the surgery and for subsequent surgery on either knee within one year. The risks of these outcomes were modeled with use of age, sex, comorbidity, hospital and surgeon volume, and inpatient or outpatient surgery as potential risk factors. RESULTS We identified 70,547 anterior cruciate ligament reconstructions, with an increase from 6178 in 1997 to 7507 in 2006. Readmission within ninety days after the surgery was infrequent (a 2.3% rate), but subsequent surgery on either knee within one year was much more common (a 6.5% rate). Patients were at increased risk for readmission within ninety days if they were over forty years of age, sicker (e.g., had a preexisting comorbidity), male, and operated on by a lower-volume surgeon. Predictors of subsequent knee surgery included being female, having concomitant knee surgery, and being operated on by a lower-volume surgeon. Predictors of a subsequent anterior cruciate ligament reconstruction included an age of less than forty years, concomitant meniscectomy or other knee surgery, and surgery in a lower-volume hospital. CONCLUSIONS The rate of anterior cruciate ligament reconstruction has increased in frequency. Also, while anterior cruciate ligament reconstruction appears to be a safe procedure, the risk of a subsequent operation on either knee is increased among younger patients and those treated by a lower-volume surgeon or at a lower-volume hospital.

Measurement error of lumbar total disc replacement range of motion.

Study Design. A retrospective review of lumbar total disc replacement (TDR) radiographs. Objective. To determine the error and variability in measuring TDR radiographic range of motion (ROM). Summary of Background Data. Motion preservation is the driving force behind lumbar TDR technology. In the recent literature, sagittal radiographic TDR ROM as low as 2° has been reported. In these studies, ROM was determined by using the Cobb method to measure TDR sagittal alignment angles in flexion-extension lateral radiographs. However, previous studies in the spinal deformity literature have shown that the Cobb method is very susceptible to measurement error. Methods. There were 5 observers, including 2 attending orthopedic spine surgeons, 1 spine fellow, 1 fifth-year resident, and 1 fourth-year resident, who measured the ROM of 50 ProDisc II (Synthes Spine Solutions, New York, NY) TDRs on standard flexion-extension lumbar spine radiograph sets. Repeated measurements were made on 2 occasions using the Cobb method. Measurement variability was calculated using 3 statistical methods. Results. The 3 statistical methods resulted in extremely similar values for TDR ROM observer variability. Overall, the intraobserver variability of TDR ROM measurement was ±4.6°, and interobserver variability was ±5.2°. Conclusions. To be 95% certain that an implanted TDR prosthesis has any sagittal motion, a ROM of at least 4.6° must be observed, which is the upper limit of intraobserver measurement variability for a TDR with a true ROM of 0°. To be 95% certain that a change in TDR ROM has occurred between 2 measurements by the same observer, a change in ROM of at least 9.6° must be observed (the entire range of ±4.6° intraobserver variability). ROM measurement variability should be considered when evaluating the success or failure of motion preservation in lumbar TDR.

Risk of Serious Injury for Young Baseball Pitchers A 10-Year Prospective Study

Background: The risk of elbow or shoulder injury for young baseball pitchers is unknown. Purpose/Hypothesis: The purpose of this study was to quantify the cumulative incidence of throwing injuries in young baseball pitchers who were followed for 10 years. Three hypotheses were tested: Increased amount of pitching, throwing curveballs at a young age, and concomitantly playing catcher increase a young pitcher’s risk of injury. Study Design: Cohort study; Level of evidence, 3. Methods: In sum, 481 youth pitchers (aged 9 to 14 years) were enrolled in a 10-year follow-up study. Participants were interviewed annually. Injury was defined as elbow surgery, shoulder surgery, or retirement due to throwing injury. Fisher exact test compared the risk of injury between participants who pitched at least 4 years during the study and those who pitched less. Fisher exact tests were used to investigate risks of injury for pitching more than 100 innings in at least 1 calendar year, starting curveballs before age 13 years, and playing catcher for at least 3 years. Results: The cumulative incidence of injury was 5.0%. Participants who pitched more than 100 innings in a year were 3.5 times more likely to be injured (95% confidence interval = 1.16 to 10.44). Pitchers who concomitantly played catcher seemed to be injured more frequently, but this trend was not significant with the study sample size. Conclusion: Pitching more than 100 innings in a year significantly increases risk of injury. Playing catcher appears to increase a pitcher’s risk of injury, although this trend is not significant. The study was unable to demonstrate that curveballs before age 13 years increase risk of injury. Clinical Relevance: The risk of a youth pitcher sustaining a serious throwing injury within 10 years is 5%. Limiting the number of innings pitched per year may reduce the risk of injury. Young baseball pitchers are encouraged to play other positions as well but might avoid playing catcher.

Cartilage Injury After Acute, Isolated Anterior Cruciate Ligament Tear Immediate and Longitudinal Effect With Clinical/MRI Follow-up

Background: Anterior cruciate ligament (ACL) tears have been implicated in the development of osteoarthritis. Limited data exist on longitudinal follow-up of isolated ACL injury. Hypotheses: All isolated ACL tears are associated with some degree of cartilage injury that will deteriorate over time. There is a threshold of magnetic resonance imaging (MRI)–detectable cartilage injury that will correlate with adverse change in subjective patient-reported outcome measures. Study Design: Cohort study, Level of evidence, 2. Methods: The authors conducted a prospective, observational analysis of 42 knees in 40 patients with acute, isolated ACL injury (14 treated nonoperatively, 28 by reconstruction) with imaging at the time of injury and yearly follow-up for a maximum of 11 years. Morphologic MRI and quantitative T2 mapping was performed with validated outcome measures. Results: All patients sustained chondral damage at initial injury. The adjusted risk of cartilage loss doubled from year 1 for the lateral compartment and medial femoral condyle (MFC) and tripled for the patella. By years 7 to 11, the risk for the lateral femoral condyle was 50 times baseline, 30 times for the patella, and 19 times for the MFC. There was increased risk of cartilage degeneration over the medial tibial plateau (MTP) (P = .047; odds ratio = 6.23; 95% confidence interval [CI], 1.03-37.90) and patella (P = .032; odds ratio = 4.88; 95% CI, 1.14-20.80) in nonsurgical patients compared with surgically treated patients. Size of the bone-marrow edema pattern was associated with cartilage degeneration from baseline to year 3 (P = .001 to .039). Each increase in the MFC Outerbridge score resulted in a 13-point decrease in the International Knee Documentation Committee subjective knee score (P = .0002). Each increase in the MTP resulted in a 2.4-point decrease in the activity rating scale (P = .002). Conclusion: All patients with acute, traumatic ACL disruption sustained a chondral injury at the time of initial impact with subsequent longitudinal chondral degradation in compartments unaffected by the initial “bone bruise,” a process that is accelerated at 5 to 7 years’ follow-up.

American collegiate men's ice hockey: an analysis of injuries.

Background Reported rates and types of ice hockey injuries have been variable. Ice hockey combines tremendous speeds with aggressive physical play and therefore has great inherent potential for injury. Purpose To identify rates and determinants of injury in American mens collegiate ice hockey. Study Design Prospective cohort study. Methods Data were collected from 8 teams in a Division I athletic conference for 1 season using an injury reporting form specific for ice hockey. Results There were a total of 113 injuries in 23 096 athlete exposures. Sixty-five percent of injuries occurred during games, although games accounted for only 23% of all exposures. The overall injury rate was 4.9 per 1000 athlete exposures (13.8 per 1000 game athlete exposures and 2.2 per 1000 practice athlete exposures). Collision with an opponent (32.8%) or the boards (18.6%) caused more than half of all injuries. Concussion (18.6%) was the most common injury, followed by knee medial collateral ligament sprains, acromioclavicular joint injuries, and ankle sprains. Conclusions The risk of injury in mens collegiate ice hockey is much greater during games than during practices. Concussions are a main cause for time lost and remain an area of major concern.

Prospective analysis of arthroscopic rotator cuff repair: Prognostic factors affecting clinical and ultrasound outcome

The purpose of this study was to identify potential predictors of function and tendon healing after arthroscopic rotator cuff repair that will enable the orthopaedic surgeon to determine which patients can expect a successful outcome. Between 2003 and 2005, the Arthroscopic Rotator Cuff Registry was established to collect demographic, intraoperative, functional outcome, and ultrasound data prospectively on all patients who underwent primary arthroscopic rotator cuff repair. At total of 193 patients met the study criteria, and 127 (65.8%) completed the 2-year follow-up. The most significant independent factors affecting ultrasound outcome were age (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.02-1.14; P = .006) and tear size (OR, 2.29; 95% CI, 1.55-3.38; P < .001). After adjustment for age and tear size, the intraoperative factors found to be significantly associated with a tendon defect were concomitant biceps procedures (OR, 11.39; 95% CI, 2.90-44.69; P < .001) and acromioclavicular joint procedures (OR, 3.85; 95% CI, 1.46-10.12; P = .006). In contrast to the ultrasound data, the functional outcome variables, such as satisfaction (OR, 3.92; 95% CI, 2.00-7.68; P < .001) and strength (OR, 10.05; 95% CI, 1.61-62.77; P = .01), had a greater role in predicting an American Shoulder and Elbow Surgeons score greater than 90. The progression from a single-tendon rotator cuff tear to a multiple-tendon tear with associated pathology increased the likelihood of tendon defect by at least 9 times, and therefore, earlier surgical intervention for isolated, single-tendon rotator cuff tears could optimize the likelihood of ultrasound healing and an excellent functional outcome.