The purpose of this study was to investigate potential differences in lead knee extension velocity, elbow varus torque and lead knee extension (the change in lead knee flexion from foot contact to ball release) in high and low velocity professional pitchers. Three-dimensional motion capture (480 Hz) was used to assess 322 professional pitchers. T-test were used to compare the two groups and multiple linear regression analyses were performed on all pitchers (n = 322). The high-velocity group (n = 99; 40.3 ± 0.9m/s) had greater lead knee extension (17 ± 13 vs 5 ± 14°, p < 0.001, g = 0.9), lead knee extension velocity (419 ± 135 vs 297 ± 121°/s, p < 0.001, g = 0.9) and elbow varus torque (91.1 ± 15.5 vs 84.0 ± 14.7 Nm, p < 0.001, g = 0.5) compared to the low-velocity group (n = 88; 36.1 ± 1.2 m/s). Lead knee extension (R² = 0.352, p < 0.001) and lead knee extension velocity (R² = 0.326, p < 0.001) were found to be positive predictors of ball velocity but not elbow varus torque (p = 0.807). Instructing professional pitchers to utilise a lead leg bracing technique that facilitates increased lead knee extension can contribute to faster ball velocity, but most likely results from a combination of other mechanics.

The utilization of recombinant human growth hormone therapy in pediatric populations, originally approved to treat diseases of growth hormone deficiency, has expanded to encompass a broader range of indications, leading to a threefold increase in its utilization in the last two decades. However, concerns regarding its safety, particularly those that are orthopedic in nature, have grown alongside its increasing popularity. Growth hormone usage has been reported to predispose patients to a multitude of common orthopedic conditions, including carpal tunnel syndrome, Legg–Calve–Perthes disease, little league shoulder, Osgood–Schlatter disease, osteochondritis dissecans, scoliosis, Sever’s disease, and slipped femoral capital epiphysis. The pathways by which growth hormone therapy can precipitate orthopedic pathology has been shown to be multifactorial, involving mechanisms such as hormonal changes, growth plate instability, rapid growth, and increased susceptibility to overuse injury. This review examines the orthopedic consequences of growth hormone therapy in pediatric patients by discussing these potential pathophysiologic mechanisms of injury and analyzing subsequent clinical manifestations. By examining processes underlying these complications, we highlight the need for orthopedic surveillance and management in children receiving GHT, particularly those with pre-existing musculoskeletal comorbidities or high levels of physical activity. Our findings underscore the importance of a multidisciplinary approach involving co-management by pediatricians, endocrinologists, and orthopedic surgeons to optimize safety and outcomes for these patients. Directions for future research include correlating pathophysiologic mechanisms to injury patterns, investigating long-term complications in recently approved growth hormone therapy indications, and informing clinical guidelines on the management of orthopedic injuries in this patient population.

Background: Patellar instability is a common condition that affects many young, active patients and can lead to long-term disability. This video aims to provide insights in the treatment of acute osteochondral fractures in skeletally immature patients after acute patellar dislocation. Indications: Patients who present with acute patellar dislocation and evidence of osteochondral fracture or osteochondral fracture with a loose body are potential candidates for medial patellofemoral ligament reconstruction (MPFLR) with osteochondral fragment fixation. Technique Description: In case 1, arthroscopy revealed a medial patellar facet defect. A medial patellar incision was made with dissection down to the vastus medialis oblique fascia and medial retinaculum. Before continuing to capsulotomy, the dissection for the MPFLR is completed by dissecting down to create a plane between layers 2 and 3. Capsulotomy is then performed with retrieval of the loose body, preparation of the patellar defect, and fixation of the osteochondral fragment. The MPFLR is then performed. An allograft is fixed to the patella with 2 pushlock anchors, and to a distally directed femoral tunnel using a 7-mm pitchfork SwiveLock tenodesis anchor, with care to avoid the medial femoral physis. The capsulotomy is then closed underneath the graft, with layer 2 closed above it. In case 2, a large osteochondral fracture of the lateral femoral condyle with loose cartilage flaps was arthroscopically identified. An anterior incision was made and a lateral lengthening was completed to perform a laterally based arthrotomy to expose the defect on the lateral femoral condyle. The defect site was prepared and the loose body was secured and fixated into the donor site lesion using bioabsorbable screws. The MPFLR was completed as in case 1, and the wound was closed in standard fashion. Results: Acute patellar dislocation with osteochondral fracture has been shown to lower both subjective and functional patient outcome measures. A recent study suggests that in large osteochondral fractures after patella dislocation, internal fixation improves mid- and long-term outcomes when compared with debridement alone. Conclusion: The MPFLR with concurrent osteochondral fracture fixation in patients with open physes is a reliable option for improving patellar stability and protecting articular cartilage from further injury. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form.

Background: Cartilage injury in the setting of acute patellar dislocation is a devastating condition that can lead to decreased quality of life and can progress to early osteoarthritis of the knee if not treated adequately. Indications: Matric-associated chondrocyte implantation (MACI) with concomitant medial patellofemoral ligament reconstruction (MPFLR) is indicated for young, high-demand patients with a symptomatic, full-thickness chondral lesions >2 cm² that have failed an initial trial of conservative management or are found to have evidence of extensive cartilage damage or loose body that is not amenable to fixation. Technique Description: The MACI technique requires a 2-stage procedure. An initial diagnostic arthroscopy aids in characterization of the chondral lesion with regard to lesion size, depth, and morphology. Hyaline cartilage was harvested and autologous chondrocytes are seeded onto a MACI scaffold to grow. At the second stage, an MPFLR is planned alongside MACI. First a midline incision is made. Notably, instead of performing the capsulotomy at this stage, we proceed with the dissection for the MPFLR first creating a plane between layer #2 and #3 for easier graft retrieval later. The defect site is prepared, and the MACI graft is seated in the defect and secured. Medial patellofemoral ligament reconstruction is then begun by fixing the preloaded semitendinosus allograft to the patella. Shottle point is confirmed via fluoroscopy and dissection down to the femoral condyle is performed. The graft is retrieved between the 2 layers that were dissected earlier in the procedure and fixed within the femoral tunnel. Finally, the synovial layer is closed deep to the MPFL graft and the vastus medialis oblique (VMO) layer is closed superficial to it before closing the wound in the standard fashion. Results: The MACI procedure demonstrates high rates of satisfaction for relief of pain and significant improvements in clinical outcomes with generally low incidence of complications. Matric-associated chondrocyte implantation has been shown to be superior to microfracture in the treatment of larger (>3 cm²) symptomatic articular defects at 5 years. Discussion/Conclusion: Matric-associated chondrocyte implantation procedure with concomitant MPFLR should be considered in indicated patients with full thickness cartilage defects that are not amenable to fixation. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.