The role of relaxin in anterior cruciate ligament injuries: a systematic review.

OBJECTIVE: Anterior cruciate ligament (ACL) tears are exceedingly common among the athletic population and are seen with higher incidence in females. Observational studies have noted peak ACL tear rates in the luteal phase of the menstrual cycle, a time in which the hormone relaxin peaks in serum concentration. METHODS: A systematic review of the literature was performed. Inclusion criteria specified all prospective and retrospective studies which included the role of relaxin in the pathogenesis of ACL tears. RESULTS: Six studies met inclusion criteria yielding 189 subjects from clinical studies and 51 in vitro samples. Included studies found that ACL samples exhibit selective relaxin binding. When pre-treated with estrogen prior to relaxin exposure, female ACL tissue samples exhibit increased expression of collagen degrading receptors. CONCLUSION: Relaxin displays binding specificity to the female ACL and increased serum concentrations are correlated with increased ACL tear rates in female athletes. Further research is needed in this area. LEVEL OF EVIDENCE: V.

The COVID-19 Pandemic Upended Youth Sports.

The American Academy of Pediatrics estimates that approximately 35 to 45 million young people age 6 to 18 years participate in some type of athletics every year. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic interrupted youth sports and left many children unable to train in-person with teammates and coaches. Given the large impact sports and physical activity have on the lives of children and adolescents, the effect that coronavirus disease 2019 restrictions have had on the psychological and physical well-being of young athletes is significant. The youth sports community has worked hard to find creative ways to safely bring children and adolescents back to the fields and courts with rules and regulations in place. Youth practices and competitions are potential spreader events for SARS-CoV-2, especially given the challenge of identifying young athletes and other participants with asymptomatic active viral infection. With the implementation of rapid result testing programs and the US Food and Drug Administration approval of a highly effective vaccine in adolescents and, most recently, in younger children, youth sports are once again becoming a place for young athletes to train, socialize, and learn invaluable lessons in teamwork and leadership. [Pediatr Ann. 2021;50(11):e450-e453.].

Biomechanical Evaluation of Pediatric Anterior Cruciate Ligament (ACL) Reconstruction Techniques With and Without the Anterolateral Ligament (ALL).

BACKGROUND: Two popular physeal-sparing procedures used in the management of anterior cruciate ligament (ACL) injuries in skeletally immature patients are the iliotibial band (ITB) ACL reconstruction (ACLR) and the all-epiphyseal (AE) ACLR. Although there has been concern for overconstraint of the lateral compartment of the knee with the ITB ACLR technique, rotational stability, as provided by the anterolateral ligament (ALL) and ACL, has not been assessed in the setting of pediatric ACLR techniques. Our hypothesis is that the ITB ACLR and AE ACLR with ALL reconstruction (ALLR) will best replicate the biomechanical profile of the intact ACL that is lost with transection of the ACL and ALL. METHODS: Eight cadaveric legs were statically loaded with an anterior drawer force and varus, valgus, internal and external rotational moments at 0, 30, 60, and 90 degrees of flexion. Displacement and rotation were recorded in the following conditions: intact ACL/intact ALL, ACL-deficient/intact ALL, ITB ACLR/intact ALL, ITB ACLR/ALL-deficient, ACL-deficient/ALL-deficient, AE ACLR/ALL-deficient, AE ACLR/ALLR. RESULTS: Both ACLR techniques reduced anterior tibial translation from the ACL-deficient state, but neither restored it to the intact state (P<0.05), except in full extension. ALL deficiency increased anterior tibial translation in the ACL-deficient state (P<0.05). In rotational testing, no significant increase was seen with transection of the ACL, but the ACL-deficient/ALL-deficient state had a significant increase in internal rotation (P<0.05). This was significantly restored to the intact state at most flexion angles with the ITB ACLR without rotational overconstraint of the lateral compartment. The AE ACLR/ALL-deficient state and AE ACLR/ALLR improved rotational stability at lower flexion angles, but not at 60 and 90 degrees. There were no significant changes in varus/valgus moments. CONCLUSIONS: In this model, the ITB ACLR provided the superior biomechanical profile between our tested reconstructions. It best corrected both AP and rotatory stability without overconstraining the knee. The AE ACLR and AE ACLR/ALLR improved both parameters but not at all flexion angles and not as robustly. ACL deficiency in the knee increased anterior tibial translation, but did not affect rotatory stability. ALL deficiency in the knee increased anterior displacement and rotational moments in the ACL-deficient state. CLINICAL RELEVANCE: Cadaveric Laboratory Study. The ITB ACLR seems to be the biomechanically superior pediatric ACLR technique to regain translational and rotational stability.

Pediatric Sports Injuries.

With increasing pediatric participation in organized sport and the early specialization of children in single sports, the number of injuries seen in the pediatric and adolescent athletic population continues to increase. Children experience acute traumatic injuries during practice and competition as well as chronic overuse injuries secondary to the repetitive stress on their developing bodies. The unique nature of the pediatric patient often requires a different diagnostic, prognostic, and treatment approach to sports injuries compared with their adult counterparts.

Hip and Groin Injuries in Dancers: A Systematic Review.

CONTEXT: Injury data on hip and groin injuries vary, and these injuries are often misrepresented or overlooked for more commonly seen injuries, such as those to the foot and ankle. OBJECTIVE: To provide a systematic review of the injury rates of hip and groin pathology in dancers and look to establish a better understanding of the occurrence of hip and groin injuries in the dancer population. DATA SOURCES: A literature search was performed using PubMed and CINAHL databases for articles published between 2000 and 2016. STUDY SELECTION: Inclusion criteria consisted of (1) documentation of the number of hip and/or groin injuries, (2) study population consisting of dancers whose training included some level of ballet, and (3) studies of levels 1 through 3 evidence. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 3. DATA EXTRACTION: A single reviewer identified studies that met the inclusion criteria. The number of overall injuries, hip/groin injuries, study participants, injured participants, training hours per week, mean age of study group, injury definition, injury reporting method, and study time frame were extracted. RESULTS: Thirteen unique studies were included in the descriptive analysis. Of the 2001 dancers included in this study, 3527 musculoskeletal injuries were seen in 1553 dancers. Of these, 345 injuries were localized to the hip and groin region (overall rate, 17.2%). An incidence rate of 0.09 hip and groin injuries per 1000 dance-hours was seen in the selected cohort studies. Of 462 professional dancers, 128 hip/groin injuries were recorded, for an injury rate of 27.7%. Of the 1539 student dancers, 217 hip/groin injuries were recorded, for an injury rate of 14.1% ( P < 0.01). CONCLUSION: Data on hip and groin injuries have many limitations. However, these injuries represent an important health issue for dancers of all skill levels, encompassing 17.2% of musculoskeletal injuries seen in dancers. An increasing rate of hip/groin injuries is seen in professional dancers compared with students.

Meniscal Allograft Transplantation: State of the Art.

Meniscal allograft transplantation has evolved over the years to provide a state-of-the-art technique for the sports medicine surgeon to utilize in preserving contact mechanics and function of the knee in irreparable meniscal pathology. However, this procedure continues to spark considerable debate on proper tissue processing techniques, acceptable indications, methods of implantation, and potential long-term outcomes.

Avoiding Complications and Technical Variability During Arthroscopically Assisted Transtibial ACL Reconstructions by Using a C-Arm With Image Intensifier.

BACKGROUND: Surgical reconstruction of the anterior cruciate ligament (ACL) can be complicated by incorrect and variable tunnel placement, graft tunnel mismatch, cortical breaches, and inadequate fixation due to screw divergence. This is the first report describing the use of a C-arm with image intensifier employed for the sole purpose of eliminating those complications during transtibial ACL reconstruction. PURPOSE: To determine if the use of a C-arm with image intensifier during arthroscopically assisted transtibial ACL reconstruction (IIAA-TACLR) eliminated common complications associated with bone-patellar tendon-bone ACL reconstruction, including screw divergence, cortical breaches, graft-tunnel mismatch, and improper positioning of the femoral and tibial tunnels. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 110 consecutive patients (112 reconstructed knees) underwent identical IIAA-TACLR using a bone-patellar tendon-bone autograft performed by a single surgeon. Intra- and postoperative radiographic images and operative reports were evaluated for each patient looking for evidence of cortical breeching and screw divergence. Precision of femoral tunnel placement was evaluated using a sector map modified from Bernard et al. Graft recession distance and tibial α angles were recorded. RESULTS: There were no femoral or tibial cortical breaches noted intraoperatively or on postoperative images. There were no instances of loss of fixation screw major thread engagement. There were no instances of graft-tunnel mismatch. The positions of the femoral tunnels were accurate and precise, falling into the desired sector of our location map (sector 1). Tibial α angles and graft recession distances varied widely. CONCLUSION: The use of the C-arm with image intensifier enabled accurate and precise tunnel placement and completely eliminated cortical breach, graft-tunnel mismatch, and screw divergence during IIAA-TACLR by allowing incremental adjustment of the tibial tunnel and knee flexion angle. Incremental adjustment was essential to accomplish this. Importantly, a C-arm with image intensifier can be used with any ACL reconstruction that incorporates tunnels in the technique, with the expectation of increase in accuracy and precision and the elimination of common complications. CLINICAL RELEVANCE: The use of an image intensifier during transtibial ACL reconstruction will substantially reduce the common complications associated with the procedure and improve both accuracy and precision of tibial and femoral tunnel placement. Use of an image intensifier unit is generalizable to an individual surgeon's preferences for graft choices and drilling techniques and will be especially valuable when the intercondylar architecture is altered from injury, time, or prior surgery.

Anterior cruciate ligament reconstruction in skeletally immature patients with transphyseal tunnels.

PURPOSE: Our purpose was to evaluate the results of transphyseal anterior cruciate ligament (ACL) reconstruction with hamstring autograft in skeletally immature patients. METHODS: Eighteen knees in 18 skeletally immature pubescent patients with a mean chronologic age of 14.2 years underwent transphyseal ACL reconstruction with hamstring autograft between 2002 and 2007. Concurrent meniscal surgery was performed in 9 knees. The final patient evaluation occurred at a mean of 43.4 months (range, 24.0 to 86.6 months) and included physical examination, KT-1000 arthrometry testing (MEDmetric, San Diego, CA), and functional outcome instruments, including the International Knee Documentation Committee subjective knee form, the Lysholm knee score, and the Tegner knee activity scale. RESULTS: At the latest follow-up, the mean International Knee Documentation Committee subjective knee score was 92.4 ± 10, the mean Lysholm knee score was 94.3 ± 8.8, and the mean Tegner activity scale score was 8.5 ± 1.4. Lachman and pivot-shift testing were negative in all knees. No restriction in knee range of motion of 5° or greater when compared with the contralateral knee was observed in any patient. The mean manual maximum side-to-side difference with KT-1000 testing was 0.29 ± 1.07 mm, and no patients had a difference greater than 3 mm. No angular deformities were noted, and all leg-length measurements were symmetric bilaterally on clinical examination. No patients had traumatic graft disruption or underwent revision ACL reconstruction, whereas 3 patients sustained an ACL injury in the contralateral leg while participating in sports. CONCLUSIONS: Transphyseal ACL reconstruction with autogenous quadrupled hamstring graft with metaphyseal fixation in skeletally immature pubescent patients yielded excellent functional outcomes in a high percentage of patients without perceived clinical growth disturbance. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

The effects of timing of pediatric knee ligament surgery on short-term academic performance in school-aged athletes.

BACKGROUND: Orthopaedic injuries negatively affect the academic lives of children. HYPOTHESIS: The timing of anterior cruciate ligament (ACL) and medial patellofemoral ligament (MPFL) reconstructions affects academic performance in school-aged athletes. STUDY DESIGN: Cohort study; Level of evidence, 2. Methods Records of patients < or = 18 years old who underwent ACL or MPFL reconstructions from 2001-2007 were reviewed retrospectively. Subjects had been administered a unique questionnaire to evaluate school life in the immediate postoperative period as well as International Knee Documentation Committee (IDKC), Lysholm, and Kujala knee-specific questionnaires. Patients were in 1 of 3 study cohorts: group A (surgery during school year), group B (surgery during school holiday), and group C (surgery during summer break). RESULTS: There were 62 subjects (53 ACL and 12 MPFL reconstructions). A higher proportion of patients in group A required being driven to school (88.5%) than groups B (63.6%) or C (64.7%) (P < .05). A lower proportion of patients in group A returned to school immediately after surgery (3.8%) than groups B (36.4%) or C (88.2%) (P < .005). Among children who had never failed a test before surgery, a higher proportion of patients in group A failed a test (36.4%) after return to school than groups B (0%) or C (0%) (P < .05). Patients in group C had higher mean Likert scores (4.5) than groups A (3.8) or B (3.7) (P = .05) in response to the question "my grades suffered in my classes." Delay in surgery was negatively correlated with IKDC, Lysholm, and Kujala questionnaire scores (P < .05). CONCLUSION: In school-aged athletes with ligamentous knee injuries receiving operative treatment, surgery on a school day causes more academic difficulties than surgery during a holiday or summer break. Academic benefits of delaying surgery during the school year must be weighed against potentially worse outcomes encountered with prolonged surgical delay.

Multidirectional instability: evaluation and treatment options.

Multidirectional instability of the shoulder is a condition defined by symptoms of shoulder instability in more than one direction. Patients typically have generalized ligamentous laxity and may be involved in repetitive overhead activities. Initial treatment is with a physical therapy program. Patients who fail non-operative treatment are candidates for arthroscopic or open stabilization procedures.