American Journal of Sports Medicine最新文献

Background: Individual maximum joint and segment angular velocities have shown positive associations with throwing arm kinetics and ball velocity in baseball pitchers.

Purpose: To observe how cumulative maximum joint and segment angular velocities, irrespective of sequence, affect ball velocity and throwing arm kinetics in high school pitchers.

Study design: Descriptive laboratory study.

Methods: High school (n = 55) pitchers threw 8 to 12 fastball pitches while being evaluated with 3-dimensional motion capture (480 Hz). Maximum joint and segment angular velocities (lead knee extension, pelvis rotation, trunk rotation, shoulder internal rotation, and forearm pronation) were calculated for each pitcher. Pitchers were classified as overall fast, overall slow, or high velocity for each joint or segment velocity subcategory, or as population, with any pitcher eligible to be included in multiple subcategories. Kinematic and kinetic parameters were compared among the various subgroups using t tests with post hoc regressions and multivariable regression models created to predict throwing arm kinetics and ball velocity, respectively.

Results: The lead knee extension and pelvis rotation velocity subgroups achieved significantly higher normalized elbow varus torque (P = .016) and elbow flexion torque (P = .018) compared with population, with equivalent ball velocity (P = .118). For every 1-SD increase in maximum pelvis rotation velocity (87 deg/s), the normalized elbow distractive force increased by 4.7% body weight (BW) (B = 0.054; β = 0.290; P = .013). The overall fast group was older (mean ± standard deviation, 16.9 ± 1.4 vs 15.4 ± 0.9 years; P = .007), had 8.9-mph faster ball velocity (32.7 ± 3.1 vs 28.7 ± 2.3 m/s; P = .002), and had significantly higher shoulder internal rotation torque (63.1 ± 17.4 vs 43.6 ± 12.0 Nm; P = .005), elbow varus torque (61.8 ± 16.4 vs 41.6 ± 11.4 Nm; P = .002), and elbow flexion torque (46.4 ± 12.0 vs 29.5 ± 6.8 Nm; P < .001) compared with the overall slow group. A multiregression model for ball velocity based on maximum joint and segment angular velocities and anthropometrics predicted 53.0% of variance.

Conclusion: High school pitchers with higher maximum joint and segment velocities, irrespective of sequence, demonstrated older age and faster ball velocity at the cost of increased throwing shoulder and elbow kinetics.

Clinical relevance: Pitchers and coaching staff should consider this trade-off between faster ball velocity and increasing throwing arm kinetics, an established risk factor for elbow injury.

Background: Pediatric lumbar spondylolysis, a stress fracture of the lumbar spine, frequently affects young athletes, and nonoperative treatment is often the first choice of management. Because the union rate in lumbar spondylolysis is lower than that in general fatigue fractures, identifying risk factors for nonunion is essential for optimizing treatment.

Purpose: To determine the risk factors for nonunion after nonoperative treatment of acute pediatric lumbar spondylolysis through multivariate analysis.

Study design: Case-control study; Level of evidence, 3.

Methods: We analyzed 574 pediatric patients (mean age, 14.3 ± 1.9 years) with lumbar spondylolysis who underwent nonoperative treatment between 2015 and 2022. Nonoperative treatment included the elimination of sports activities, bracing, and weekly athletic rehabilitation, with follow-up computed tomography. Patient data, lesion characteristics, sports history, presence of spina bifida occulta at the lamina with a lesion or at the lumbosacral spine excluding the lesion level, and lumbosacral parameters were examined. Differences between the union and nonunion groups were investigated using multivariate analysis to determine the risk factors for nonunion.

Results: Of the 574 patients, 81.7% achieved bone union. Multivariate analysis revealed that an L5 lesion and the progression of the main and contralateral lesion stages were significant independent risk factors for nonunion. An L5 lesion had a lower union rate than non-L5 lesions. As the main lesion progressed, the likelihood of nonunion increased significantly, and the progression of the contralateral lesion also showed a similar trend. Spina bifida occulta and lumbosacral parameters were not significant predictors of nonunion in this study.

Conclusion: We identified the L5 lesion level and the progression of the main and contralateral lesion stages as independent risk factors for nonunion in pediatric lumbar spondylolysis after nonoperative treatment. These findings aid in treatment decision-making. When bone union cannot be expected with nonoperative treatment, symptomatic treatment is required without prolonged external fixation and rest, and without aiming for bone union. Individualized treatment plans are crucial based on identified risk factors.

Background: Hamstring strain injuries (HSIs) are prevalent in US National Football League (NFL) players, but there is a paucity of information regarding imaging characteristics, injury severity, and player factors associated with time missed and risk of recurrent injury.

Purpose: To describe player, football activity, clinical, and imaging characteristics of NFL players with HSIs, as well as determine player characteristics, clinical examination results, and magnetic resonance imaging (MRI) findings associated with injury occurrence, severity, and missed time.

Study design: Cross-sectional study; Level of evidence, 3.

Methods: A retrospective cohort of NFL players with acute HSI (n = 180) during the 2018-2019 season was identified. Injury data were collected prospectively through a league-wide electronic health record system. Three musculoskeletal radiologists graded MRI muscle injury parameters using the British Athletics Muscle Injury Classification (BAMIC) system. Player, football, clinical, and imaging characteristics were correlated with HSI incidence and severity and with missed time from sport.

Results: Of the 1098 HSIs identified during the 2018-2019 season, 416 (37.9%) were randomly sampled, and 180 (43.3%) had diagnostic imaging available. Game activity, preseason period, and wide receiver and defensive secondary positions disproportionately contributed to HSI. The biceps femoris was the most commonly injured muscle (n = 132, 73.3%), followed by the semimembranosus (n = 24, 13.3%) and semitendinosus (n = 17, 9.4%) muscles. The most common injury site was the distal third of the biceps femoris and semitendinosus muscles (n = 60, 45.5% and n = 10, 58.8%, respectively) and central part of the semimembranosus muscle (n = 17, 70.8%). Nearly half of the injuries (n = 83, 46.1%) were BAMIC grade 2; 25.6% (n = 46), grade 3; and 17.8% (n = 32), grade 4. MRI showed sciatic nerve abnormality in 30.6% (n = 55) of all HSIs and 81.3% (n = 26) of complete tendon injuries. BAMIC grade correlated with both median days and games missed. Combined biceps femoris and semitendinosus injuries resulted in the highest median days missed (27 days).

Conclusion: Among NFL players with acute HSIs, the most common injury was a moderate-severity injury of the distal biceps femoris. BAMIC grade was associated with missed time.

Background: The 6th International Consensus Statement on Concussion in Sport guidelines identified that measuring autonomic nervous system dysfunction using orthostatic vital signs (VSs) is an important part of the clinical evaluation; however, there are limited data on the frequency of autonomic nervous system dysfunction captured via orthostatic VSs after concussion.

Purpose: To compare orthostatic changes in heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) between athletes with acute sport-related concussion (SRC) and control athletes.

Study design: Cross-sectional study; Level of evidence, 3.

Methods: We compared 133 athletes (mean age, 15.3 years; age range, 8-28 years; 45.9% female) with acute SRC (<30 days after injury) with 100 control athletes (mean age, 15.7 years; age range, 10-28 years; 54.0% female). Given the broad age range eligible for study inclusion, participants were subdivided into child (younger than 13 years of age), adolescent (13-17 years of age), and adult (18 years of age and older) age groups for subanalyses. Participants completed a single standard orthostatic VS evaluation including HR, SBP, and DBP in the supine position then immediately and 2 minutes after standing. Linear regression was used to compare delayed supine-to-standing changes in HR, SBP, and DBP as a continuous variable (ΔHR, ΔSPB, and ΔDBP) between groups, and logistic regression was used to compare patients with positive orthostatic VS changes (sustained HR increase ≥30 beats per minute [bpm], SBP decrease ≥20 mm Hg, and DBP ≥10 mm Hg at 2 minutes) between groups, accounting for age and sex.

Results: Between-group differences were present for delayed ΔHR (18.4 ± 12.7 bpm in patients with SRC vs 13.2 ± 11.0 bpm in controls; P = .002) and ΔSPB (-3.1 ± 6.6 bpm in patients with SRC vs -0.4 ± 6.5 bpm in controls; P = .001), with positive orthostatic HR changes present more frequently in patients with SRC (18% vs 7%; odds ratio, 2.79; P = .027). In the SRC group, a weak inverse relationship was present between age and ΔHR (r = -0.171; P = .049), with positive orthostatic HR findings occurring primarily in the child and adolescent SRC subgroups.

Conclusion: Patients with acute SRC had greater orthostatic VS changes compared with controls, the most prominent being sustained HR elevations. Clinical evaluation of autonomic change after SRC via standard orthostatic VS assessment may be a helpful clinical biomarker in the assessment of SRC, especially in children and adolescents.

Background: High ankle sprains are common athletic injuries and can be associated with long-term sequelae. Regardless of operative or nonoperative treatment, there is a paucity of data in the literature about the long-term outcomes of high ankle sprains.

Hypothesis: Nonoperative treatment of high ankle sprains utilizing a standardized protocol will result in good long-term outcomes.

Study design: Case series; Level of evidence, 4.

Methods: Patients who experienced a high ankle sprain without radiographic diastasis of the syndesmosis were identified from a previous study database and contacted for long-term follow-up. All patients were high school or National Collegiate Athletic Association Division IA athletes at initial injury and were treated nonoperatively with the same standardized protocol. Patients completed a questionnaire that included documentation of any interim ankle injuries, 2 different patient-reported outcome scores, and ankle radiographs to conduct Kellgren-Lawrence scoring for ankle osteoarthritis.

Results: In total, 76 cases in 74 patients were identified in the database. A total of 40 patients were successfully contacted, and 31 patients (24 collegiate and 7 high school athletes) with 33 high ankle sprains completed the survey (31/40; 77.5%). The mean age at follow-up was 45 years (range, 34-50 years), with a mean time from injury to follow-up of 25 years. Overall, 93.5% (n = 29) of the respondents were male, and 42% (n = 13) of the respondents reported an ipsilateral ankle injury since their initial injury, with 16% (n = 5) having ankle or Achilles surgery. The mean Patient-Reported Outcomes Measurement Information System-10 score was 53.4 (SD, 8.3; range, 37.4-67.7), PROMIS median (IQR), 54.1 (39.9, 68.3), and the mean Self-reported Foot and Ankle Score score was 42.7 (SD, 5.86). Follow-up ankle radiographs were obtained in 11 (35%) of the respondents; 27% had Kellgren-Lawrence grade >2 osteoarthritis, and 36% had signs of heterotopic ossification on imaging. The mean tibiofibular clear space was 4.5 mm, and the mean tibiofibular overlap was 7.15 mm, with 27% of patients demonstrating some tibiotalar narrowing.

Conclusion: At long-term follow-up, nonoperative management of high ankle sprains without diastasis on imaging was associated with acceptable patient-reported functional outcomes and low rates of subsequent ankle injuries. There was a high incidence of arthritis, but most cases were not clinically significant. This case series shows the natural history of nonoperatively treated high ankle sprains and may serve as a comparison for different management techniques in the future.

Background: Limited data are available regarding career length and competition level after combined anterior cruciate ligament (ACL) and medial- or lateral-sided surgeries in elite athletes.

Purpose: To evaluate career length after surgical treatment of combined ACL plus medial collateral ligament (MCL) and ACL plus posterolateral corner (PLC) injuries in elite athletes and, in a subgroup analysis of male professional soccer players, to compare career length and competition level after combined ACL+MCL or ACL+PLC surgeries with a cohort who underwent isolated ACL reconstruction (ACLR).

Study design: Cohort study; Level of evidence, 3.

Methods: A consecutive cohort of elite athletes undergoing combined ACL+MCL and ACL+PLC surgery was analyzed between February 2001 and October 2019. A subgroup of male elite soccer players from this population was compared with a previously identified cohort having had isolated primary ACLR without other ligament surgery. A minimum 2-year follow-up was required. Outcome measures were career length and competition level.

Results: A total of 98 elite athletes met the inclusion criteria, comprising 50 ACL+PLC and 48 ACL+MCL surgeries. The mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Return-to-play (RTP) time was significantly longer for ACL+PLC injuries (12.8 months; P = .019) than for ACL+MCL injuries (10.9 months). In the subgroup analysis of soccer players, a significantly lower number of players with combined ACL+PLC surgery were able to RTP (88%; P = .003) compared with 100% for ACL+MCL surgery and 97% for isolated ACLR, as well as requiring an almost 3 months longer RTP timeline (12.9 months; P = .002) when compared with the isolated ACL (10.2 months) and combined ACL+MCL (10.0 months) groups. However, career length and competition level were not significantly different between groups.

Conclusion: Among elite athletes, the mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Professional soccer players with combined ACL+PLC surgery returned at a lower rate and required a longer RTP time when compared with the players with isolated ACL or combined ACL+MCL injuries. However, those who did RTP had the same career longevity and competition level.

Background: The potential influence of a preoperative anterolateral ligament (ALL) lesion seen on magnetic resonance imaging (MRI) on the mid- and long-term surgical outcomes of anterior cruciate ligament (ACL) reconstruction is still controversial.

Purpose: To evaluate the clinical outcomes and failure rate of isolated ACL reconstruction at a minimum 5-year follow-up in patients with and without ALL injury diagnosed preoperatively using MRI.

Study design: Cohort study; Level of evidence, 2.

Methods: A prospective cohort of patients with acute ACL injury was divided into 2 groups based on the presence (ALL injury group) or absence (control group) of ALL injury on preoperative MRI. This is a longer-term follow-up study of a previously published study that had a minimum 2-year follow-up. Both groups underwent anatomic isolated reconstruction of the ACL. The Lysholm and subjective International Knee Documentation Committee scores, KT-1000 arthrometer and pivot-shift tests, reconstruction failure rate, incidence of contralateral ACL injury, presence of associated meniscal injury, and presence of knee hyperextension were evaluated. The evaluation at the 5-year follow-up was also compared with the same patient's evaluation at 2 years of follow-up.

Results: A total of 156 patients were evaluated. No significant differences were found between the groups in the preoperative evaluation. In the postoperative evaluation, patients in the ALL injury group had a higher reconstruction failure rate (14.3% vs 4.6% for the control group; P = .049) and worse clinical outcomes according to the Lysholm scores (85.0 ± 10.3 vs 92.3 ± 6.6; P < .00001). Although the pivot-shift test results were similar, anteroposterior translation using the KT-1000 arthrometer revealed worse results for the ALL injury group (2.8 ± 1.4 mm vs 1.9 ± 1.3 mm; P = .00018). Patients in the ALL injury group also had an increase in KT-1000 arthrometer values from 2 to 5 years (2.4 ± 1.6 vs 2.8 ± 1.4; P = .038). Patients in the control group had no differences in outcomes from 2 to 5 years of follow-up.

Conclusion: Combined ACL and ALL injuries were associated with significantly less favorable outcomes than were isolated ACL injuries at a minimum follow-up of 5 years after isolated ACL reconstruction with hamstring autograft. Patients with concomitant ALL injury showed a higher failure rate and worse functional scores. Also, knee stability tended to slightly worsen from 2 to 5 years in cases of associated ALL injury.