OBJECTIVE: Calcaneal apophysitis (Sever\'s disease) is an overuse condition caused by repetitive traction stress to the calcaneal apophysis. Whether Achilles tendon morphology is altered in this young patient population remains unknown. Therefore, we aimed to identify differences in Achilles tendon morphology between youth athletes diagnosed with calcaneal apophysitis and healthy controls.
METHODS: This retrospective chart review included 46 patients (n = 23 Sever\'s disease, 15F/8M, 12.4 ± 2.3 years old) and (n = 23 healthy controls, 13F/10M, 15.9 ± 1.5 years old) who sought care in a Children\'s Hospital Sports Medicine/Orthopedics Department between 2012 and 2022. We measured ultrasound-derived degree of tendon thickening, Achilles tendon thickness (cm), and cross-sectional area (CSA [cm2]). Separate multivariate analyses of covariance (MANCOVAs) were used to compare degree of thickening, mass-normalized Achilles tendon thickness, and CSA between participant groups, covarying for age. Cohen\'s d effect sizes were used to assess the magnitude of mean differences and standard error (MDSE) between groups.
RESULTS: Young athletes with Sever\'s disease had a significantly greater degree of tendon thickening with a large effect compared with healthy controls (MDSE: 0.07 [0.01] mm P < .001, d = 1.39). Achilles tendon thickness and CSA did not statistically differ between groups; however, the magnitude of between-group differences for these measures (MDSE: 0.18 [0.05] cm, MDSE: 0.27 [0.07] cm2, respectively) were moderate.
CONCLUSIONS: Our findings demonstrate previously unrecognized differences in Achilles tendon morphology between young athletes with clinically diagnosed Sever\'s disease and healthy controls. Our study supports incorporating diagnostic ultrasound as part of a comprehensive examination to ensure appropriate diagnosis and clinical management for adolescents with heel pain.

Transarterial embolization for the treatment of chronic musculoskeletal diseases is gaining increasing interest in the field of interventional radiology. Overuse sports injury is defined as an injury occurring in the absence of a single, identifiable traumatic cause. In the treatment of this condition, there is a need for reliable results and a quick return to activity. Minimally invasive treatments with short periods of missed practice are required. Intra-arterial embolization has the potential to meet this need. In this article, we describe cases of embolization for refractory overuse sports injuries including patellar tendinopathy, pes anserine, plantar fasciitis, triangular fibrocartilage complex injury, hamstring injury, infrapatellar fat pad inflammation, Achilles tendinopathy, delayed union metatarsal bone fracture, lumbar spondylolysis, and repetitive hamstrings strain.

Patients with transfemoral amputation and socket prostheses are at a heightened risk of developing musculoskeletal overuse injuries, commonly due to altered joint biomechanics. Osseointegrated prostheses, which involve direct anchorage of the prosthesis to the residual limb through a bone anchored prosthesis, are a novel alternative to sockets yet their biomechanical effect is largely unknown.
Four patients scheduled to undergo unilateral transfemoral prosthesis osseointegration completed two data collections (baseline with socket prosthesis and 12-months after prosthesis osseointegration) in which whole-body kinematics and ground reaction forces were collected during stand-to-sit tasks. Trunk, pelvis, and hip kinematics, and the surrounding muscle forces, were calculated using subject-specific musculoskeletal models developed in OpenSim. Peak joint angles and muscle forces were compared between timepoints using Cohen\'s d effect sizes.
Compared to baseline with socket prostheses, patients with osseointegrated prostheses demonstrated reduced lateral trunk bending (d = 1.46), pelvic obliquity (d = 1.09), and rotation (d = 1.77) toward the amputated limb during the stand to sit task. This was accompanied by increased amputated limb hip flexor, abductor, and rotator muscle forces (d> > 0.8).
Improved lumbopelvic movement patterns and stabilizing muscle forces when using an osseointegrated prosthesis indicate that this novel prosthesis type likely reduces the risk of the development and/or progression of overuse injuries, such as low back pain and osteoarthritis. We attribute the increased muscle hip muscle forces to the increased load transmission between the osseointegrated prosthesis and residual limb, which allows a greater eccentric ability of the amputated limb to control lowering during the stand-to-sit task.

The young, overhead throwing athlete is prone to overuse injuries because of their variable skeletal maturity and often improper technique. An overuse injury to the digit(s) in the overhead throwing athlete, Little Leaguer\'s Finger, has never been discussed in the literature to our knowledge. We present a case of a 14-year-old man with atraumatic pain, swelling, and edema to his dominant pitching index finger after throwing greater than 90 pitches in one setting. Initial workup of the patient, including an MRI, ruled out an infectious process, and it was determined that there was a stress epiphysitis within the proximal phalanx of the digit. Symptoms within the digit resolved given time, rest, and cessation of throwing activities. The purpose of this report was to stress the importance of establishing the etiology of finger pain in the throwing athlete and to describe a previously unreported overuse injury, Little Leaguer\'s Finger.

Patellar tendon (PT) complaints are frequent throughout the population, with increased occurrence in athletes and, particularly, in youth competitive alpine skiers. Timely detection and treatment might improve prospects of recovery. Diagnostic modalities in clinical use to date rely on pain symptoms, manual palpation, and potentially, magnetic resonance imaging (MRI); however, MRI-based imaging yields limited sensitivity. Quantitatively measuring the morphological and mechanical properties of PTs by means of B-mode ultrasound and shear wave elastography (SWE), instead, may allow improved diagnosis or even early detection. We performed B-mode scans and three-dimensional ultrasound shear wave velocity (SWV) mapping and MRI of the PT in 106 youth skiers. A prospective one-year survey on health problems combined with clinical assessments served to categorize symptomatic and asymptomatic youth skiers. Skiers suffering from distal or proximal tendon complaints showed lower SWV in the respective tendon region than asymptomatic skiers (p = 0.035 and p = 0.019, respectively). Youth skiers with distal tendon complaints additionally exhibited decreased SWV in the proximal region compared to asymptomatic counterparts (p = 0.020). Cross-validated analysis of retrospective prediction indicated sensitivity and specificity in detecting tendon complaints in the range of 0.606-0.621 and 0.536-0.650, respectively. MRI detected distal tendon complaints with a sensitivity of 0.410 (12/29) but failed to detect any proximal cases. This study agrees with the most recent literature in that SWE holds promise as a valuable adjunct modality for the diagnosis of PT complaints or even the detection of subclinical prestages. However, to evaluate its prospective predictive value, long-term studies are warranted.Highlights Patellar tendon complaints are a frequent complaint in athletes, particularly in youth competitive alpine skiers, but timely quantitative detection of related tendon properties remains challenging.Quantitative B-mode US and three-dimensional ultrasound shear wave elastography assessments and magnetic resonance imaging were performed in youth competitive alpine skiers.Three-dimensional shear wave elastography was able to discern symptomatic from asymptomatic patellar tendons both in the distal and proximal tendon regions, whereas magnetic resonance imaging failed to detect any proximal cases.

Overuse injuries of the knee are a common cause of missed training and competition days in elite cyclists, however the underlying conditions causing this knee pain are not well defined. We conducted a diagnostic study, investigating a consecutive series of 53 high level cyclists with non-traumatic knee pain over a 14 month period. Demographic data on the participants\' cycling specialty and training level was noted. Clinical information concerning knee pain intensity, location and occurrence were collected using a questionnaire. Our results show 7 different overuse injuries were identified. The prepatellar friction syndrome accounted for the majority of these overuse injuries (46%), while medial plica syndrome (15%), biceps femoris tendinopathy (7.5%), patellar tendinopathy (9.4%), infrapatellar plica friction syndrome (7.5%), infrapatellar fat pad impingement (5.7%) and iliotibial band syndrome (3.7%) were other causes of knee pain in these athletes. In contrast to current belief, our results show that instead of patellofemoral cartilage overload, friction related overuse injuries are the most frequent and underestimated cause of knee pain in high level cyclists.

Sacral stress fractures are rare injuries among professional and amateur athletes and are considered to be an uncommon source of low back pain. These type of fractures are mainly seen in competitive, high-impact sports, most commonly in long-distance runners. Sacral stress fractures are usually overlooked in young patients presenting with low back pain without any trauma history. Diagnosis of sacral stress fractures is often delayed because the history and physical examination of these patients are not specific and conventional radiographic images are frequently inadequate. A high index of clinical suspicion and further radiologic imaging such as MRI utilization can provide the accurate diagnosis. The treatment mainly includes rest, pain control, nutritional support, and biomechanical optimization. Herein, we report the case of a woman amateur golf player with a sacral stress fracture who complained of aggravating low back pain. To the best of our knowledge, this appears to be the first report of a sacral stress fracture in a golf player and also the first case of this pathology in low-impact sports. Therefore, physicians should keep in mind that stress fractures can also be seen in low-impact sports. We recommend considering stress fractures in the differential diagnosis of non-traumatic, aggravating low back pain in golfers.

Overuse myositis ossificans is considered an extremely rare diagnosis, with only a few cases reported so far. A case of a 54-year-old firefighter, involved regularly in training exercises, with bilateral myositis ossificans of the triceps, is presented. The patient had a 4 year history of painful masses at the posterior region of both arms. He never experienced any traumatic event, while physical examination revealed firm masses extending longitudinally within the lateral head of the triceps, bilaterally. The patient had painful restricted range of motion at both sides. Plain X-ray views of the humerus showed linear lobulated heterogeneous masses posterolateral. Surgical resection of both masses, which extended intramuscularly through the whole lateral triceps\' head, was performed. Histological examination confirmed the diagnosis of myositis ossificans. Myositis ossificans represents a benign, relative rare clinical entity, defined as heterotopic ossification of the soft tissues. Only 5 cases of myositis ossificans due to overuse have been described so far. The present case is unique, since it is the first one describing bilateral appearance of two masses which extended through the whole length of the lateral head of the triceps. A detailed medical history, as well as imaging examination seem to be necessary in order to establish the diagnosis. Treatment should be decided upon the stage of the lesion. For mature lesions surgical treatment is advised.

Paget-Schroetter Syndrome is a rare condition in the spectrum of deep vein thromboses involving spontaneous upper extremity venous thrombosis in the axillary-subclavian vein. The syndrome usually occurs in young, healthy individuals and is a progressive, anatomic manifestation of venous thoracic outlet syndrome. Thrombosis is secondary to repetitive overuse of the arm, leading to compression, microtrauma, and local inflammation of the particularly vulnerable subclavian vein in the thoracic outlet at the junction of the first rib and clavicle. The condition is often misdiagnosed because of its rarity and can lead to significant disability and morbidity if treatment is delayed. In this case report, Paget-Schroetter Syndrome, causing significant pain and dysfunction, is presented in an 18 year-old female freestyle-swimmer that was successfully treated with anticoagulation, thrombolysis, thoracic outlet decompression and first rib resection, scalenectomy, venolysis, and venoplasty. Early suspicion of this condition can lead to prompt diagnosis, and subsequent aggressive interventional treatment with catheter-directed thrombolysis and thoracic outlet decompression, in addition to anticoagulation, demonstrated success in achieving complete resolution of symptoms in this case.

The use of snap-fits in car-part assembling has developed into an industrial standard. Cross-sectional evidence indicates, however, that this assembling process might adversely affect workers\' upper limb function. The objective of this study was to analyze incident cases of upper limb functional limitations (ULFL) in relation to exposure to snap-fit assembly.
We performed a nested case-control study within a population of 5139 blue-collar automotive production workers. Cases with ULFL detected during follow-up were matched with controls based on employment duration and investigated on their exposure to snap-fit assembly. By conditional logistic regression, we modeled the risk for ULFL according to person-years of exposure to snap-fit assembly, adjusted for gender and baseline BMI.
Overall, 64 ULFL cases were detected during a follow-up of 20610.8 person-years (3.1 cases per 1000 person-years). Cases, matched with an average of 4 controls, had significantly longer exposure duration to snap-fit assembly compared with controls (M = 1.15 person-years, SD = 1.68 person-years vs. M = 0.41 person-years, SD = 1.25 person-years). One person-year of exposure to snap-fit assembly was associated with an approximate 20% risk increase of developing ULFLs (OR 1.23, 95% CI 1.08-1.39).
We confirm an association between accumulated exposure to snap-fits in car-part assembling and upper limb musculoskeletal disorders. Company physicians should thus be vigilant to symptoms of musculoskeletal disorders of the upper limbs in snap-fit assembly and support the development of threshold values for snap-fit insertion forces.