Medial Collateral Ligament Reconstruction of the Knee: The Modified Marx Technique With Adjustable-Loop Femoral Fixation and Posteromedial Corner Plication.

The medial collateral ligament serves as the primary stabilizer to valgus stress on the medial side of the knee and is the most commonly injured ligament in the knee. Medial collateral ligament reconstruction can provide improved stability and clinical outcomes for patients. Advancements in techniques, including the use of an adjustable-length-loop suspensory fixation device through a longitudinal incision, have been introduced in recent years. The purpose of this Technical Note and video is to provide a minimally invasive method for medial collateral ligament reconstruction with adjustable-loop femoral fixation and posteromedial corner plication.

Chronic Q fever presenting as bilateral extensor tenosynovitis: a case report and review of the literature.

Musculoskeletal manifestations of Coxiella burnetii are rare. We describe an elderly, immunosuppressed male with bilateral Coxiella burnetii extensor tenosynovitis treated with incision and debridement and chronic doxycycline and hydroxychloroquine. Additionally, disease etiology, risk factors, pertinent features of the history, testing modalities, and treatment strategies of musculoskeletal Q fever are reviewed.

Changes in Elbow Stress and Ball Velocity During Reduced Effort Pitching: A Marker-Based Motion Capture Analysis.

BACKGROUND: Baseball pitchers often participate in throwing programs that involve throwing at reduced effort levels to gradually increase the amount of stress experienced across the elbow. It is currently unknown how reduced effort pitching compares with maximum effort with respect to elbow stress and ball velocity. PURPOSE/HYPOTHESIS: The purpose was to determine the correlation between elbow stress and ball velocity with reduced effort pitching. We hypothesized that decreased perceived effort would disproportionately correlate with elbow stress and ball velocity. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten healthy male high school baseball pitchers threw 5 pitches from a regulation pitching mound at 3 effort levels: maximum effort, 75% effort, and 50% effort. Elbow stress, specifically elbow varus torque, was calculated for all pitches using a validated marker-based 3-dimensional motion capture system. Ball velocity was measured using a Doppler radar gun. Intrathrower variability was calculated for each effort level. RESULTS: Elbow stress and ball velocity decreased with reduced effort throws (P < .001 and P = .003, respectively). However, the reductions in elbow stress and ball velocity were not proportional. At 75% effort throws, elbow stress measured 81% (intraclass correlation coefficient [ICC], 0.95), and ball velocity measured 90% (ICC, 0.80) of maximum, respectively. At 50% effort throws, elbow stress measured 75% (ICC, 0.93), and ball velocity measured 85% (ICC, 0.87) of maximum. Intrathrower reliability was excellent for elbow stress and ball velocity, with all ICCs ≥0.80. CONCLUSION: Pitching at a reduced effort level resulted in decreased elbow stress and ball velocity. However, for every 25% reduction in perceived effort, elbow stress decreased by a mean 13%, and ball velocity decreased 7.5%. When baseball pitchers attempt to throw at a reduced effort of maximum, throwing metrics do not decrease proportionately. CLINICAL RELEVANCE: While pitching at a reduced effort of maximum decreases elbow stress and ball velocity, the decrease is not proportional, subjecting the elbow to more stress than intended. This has significant clinical importance to pitchers, coaches, and medical professionals in the setting of injury prevention and return to sports.

Are Wearable Sensors Valid and Reliable for Studying the Baseball Pitching Motion? An Independent Comparison With Marker-Based Motion Capture.

BACKGROUND: In recent years, the prevalence of medial ulnar collateral ligament injuries has increased in throwers of all ages and skill levels. The motusBASEBALL sensor possesses an inertial measurement unit (IMU) that has been developed and applied to the throwing arm to allow for measurements of several objective parameters, which may prove beneficial for monitoring, rehabilitation, and injury prevention in the throwing athlete. However, the reliability, consistency, and validity of the IMU have not been independently assessed. PURPOSE: To evaluate the reliability, consistency, and validity of the motusBASEBALL sensor compared with the historic gold standard of marker-based motion capture. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 10 healthy male baseball athletes with varsity-level high school experience volunteered to participate in this study. Participants were fitted with 37 retroreflective markers for motion capture and the motusBASEBALL IMU sensor. Participants threw 5 fastballs at maximum effort, with measurements recorded simultaneously by motion capture and the IMU. Arm slot, arm speed, arm stress, and shoulder rotation were measured and compared. RESULTS: Of the 4 metrics generated by the IMU, significant differences were found for 3 of the throwing metrics compared with motion capture including arm slot (5.0°± 6.1°; P = .037), elbow varus torque (9.4 ± 12.0 N·m; P = .037), and shoulder rotation (6.3°± 6.1°; P = .014). Arm speed did not demonstrate a statistically significant difference (29.2 ± 96.8 rpm; P = .375). The IMU consistently underreported pitching performance values. Shoulder rotation exhibited excellent reliability with <5° of error, and arm slot demonstrated good reliability with <10° of error. Arm stress and arm speed were less reliable. CONCLUSION: The IMU was not accurate or valid for arm slot, arm stress, and shoulder rotation compared with marker-based motion capture. It was relatively accurate for arm speed. Despite its lack of validity, it was consistent and reliable for arm speed and shoulder rotation and relatively reliable for arm slot and arm stress. Caution should be used when comparing values provided by this IMU to the gold standard of marker-based motion capture. CLINICAL RELEVANCE: IMU technology has potential to be used in monitoring, rehabilitation, and injury prevention in throwing athletes if valid. This study demonstrates that the values provided by the IMU should not be considered equivalent to those generated by the gold standard of marker-based motion capture; however, there may still be a role for this technology when relying on its internal consistency for intrathrower comparisons and tracking.

Primary Cutaneous Osteosarcoma.

Primary cutaneous osteosarcoma is an exceedingly rare malignant mesenchymal neoplasm of the skin which produces bone, osteoid, or chondroid material and does not involve the underlying bone. The most common site for extraskeletal osteosarcoma is in the deep soft tissues of the thigh, upper extremities, and retroperitoneum; however, it may occur anywhere in the body. Involvement of the skin is rare and when it does occur it is more commonly due to metastatic disease rather than a primary malignancy. Only 16 cases of primary cutaneous osteosarcoma have been described in the literature. We report an uncommon case of primary cutaneous osteosarcoma. Our patient is an 84-year-old male with an unremarkable medical history who presented to the dermatology clinic complaining of a 0.5 x 0.4 cm pink flesh to translucent-appearing, shiny, papule on the right superior jawline which was not connected to the underlying bone. Clinically the differential diagnosis included basal cell carcinoma, trichoepithelioma, and other cutaneous adnexal tumors. An excisional biopsy was performed which demonstrated an unremarkable epidermis with a hypercellular reticular dermis with occasional large spindled cells with amphophilic cytoplasm. The deep dermis was involved by mature osteoid formation and infiltration of highly mitotically active, atypical epithelioid and spindled cells with abundant nuclear pleomorphism, amphophilic cytoplasm, and poorly defined cell borders. Occasional multinucleate forms were seen. Immunohistochemistry was performed which showed strong positive staining with vimentin. Without connection to the underlying bone, osteosarcoma of periosteal, parosteal, or osseous origin was excluded. Based on these histomorphologic findings, a diagnosis of primary cutaneous osteosarcoma was made. Our case adds to the dearth of literature regarding primary cutaneous osteosarcoma and provides primary care physicians, dermatologists, and pathologists much needed insight into this rare condition.

Coexistent Alpha-1 Antitrypsin Deficiency and Hereditary Hemochromatosis.

Alpha-1 antitrypsin (AAT) deficiency and hereditary hemochromatosis are systemic diseases inherited in an autosomal recessive fashion. The primary manifestation of AAT is early-onset pulmonary disease, while hemochromatosis primarily affects function of the liver, heart, and pancreas through excess iron deposition. No clear association between the two diseases has been delineated. We present a case in which a 34-year old female patient presenting with elevated liver enzymes during a visit for an unrelated acute illness was found to be a homozygous variant for AAT deficiency and hereditary hemochromatosis. A description of her presentation and clinical work up is included, along with a discussion of the epidemiology and clinical characteristics of each disease.