Anatomic anterior cruciate ligament reconstruction: a changing paradigm.

Injury to the anterior cruciate ligament (ACL) of the knee is potentially devastating for the patient and can result in both acute and long-term clinical problems. Consequently, the ACL has always been and continues to be of great interest to orthopaedic scientists and clinicians worldwide. Major advancements in ACL surgery have been made in the past few years. ACL reconstruction has shifted from an open to arthroscopic procedure, in which a two- and later one-incision technique was applied. Studies have found that traditional, transtibial arthroscopic single-bundle reconstruction does not fully restore rotational stability of the knee joint, and as such, a more anatomic approach to ACL reconstruction has emerged. The goal of anatomic ACL reconstruction is to replicate the knee's normal anatomy and restore its normal kinematics, all while protecting long-term knee health. This manuscript describes the research that has changed the paradigm of ACL reconstruction from traditional techniques to present day anatomic and individualized concepts.

The fetal anterior cruciate ligament: an anatomic and histologic study.

PURPOSE: The purposes of this study were to better understand the fetal development of the anterior cruciate ligament (ACL); to identify the gross anatomy of the ACL; to perform a complete histologic evaluation of the ligament, particularly with respect to the distinction between bundles; and to evaluate ACL length, diameter, cellularity, vascularity, and insertion sites. METHODS: By use of 40 intact knee joints of human fetuses, the gross anatomy of the ACL was inspected under a stereomicroscope (n = 40). The histologic evaluation was performed on the sagittal (n = 20) and transverse (n = 10) sections. RESULTS: The gross observations revealed the presence of 2 distinct bundles: anteromedial (AM) and posterolateral (PL). The femoral origin of each ACL bundle was located in the posterior aspect of the medial surface of the lateral femoral condyle. The footprint of the tibial insertion was ovoid, with the AM bundle located anterior and medial to the PL bundle. The mean length of the ACL was 3.7 mm, the mean width was 1.1 mm, and the mean thickness was 0.9 mm. There was high cellularity, with approximately 5,600 cells/mm2, and intense vascularity. The AM and PL bundles were divided by a well-defined septum. The femoral origin had less dense connective tissue compared with the tibial insertion. CONCLUSIONS: From the time of fetal development, the ACL is composed of 2 bundles, AM and PL. The gross morphology of the ACL in fetuses is similar to that reported in adults; the histology is diverse in cellularity and vascularity. CLINICAL RELEVANCE: This study provides useful information about the anatomy and histology of the fetal ACL.

Effects on lung function of multiple expansion thoracoplasty in children with thoracic insufficiency syndrome: a longitudinal study.

STUDY DESIGN: Longitudinal study of intraoperative pulmonary function in young children with thoracic hypoplasia and scoliosis undergoing multiple expansion thoracoplasty using the vertical expandable prosthetic titanium ribs (VEPTRs). OBJECTIVE: To test the long-term efficacy of VEPTR multiple expansion thoracoplasty. SUMMARY OF BACKGROUND DATA: To our knowledge, no direct measurements of pulmonary function have been reported with VEPTR expansion thoracoplasty. METHODS: There were 10 children with thoracic insufficiency syndrome, secondary to thoracic hypoplasia with progressive scoliosis, studied. A mobile pulmonary function laboratory unit was used to study forced vital capacity (FVC), maximum expiratory flow volume curves, and respiratory system compliance (Crs) with the patient under general anesthesia immediately before and after expansion thoracoplasty. Studies were repeated every 6 months at each subsequent operation for expansion thoracoplasty for the duration up to 33 months. RESULTS: At the baseline studies, FVC showed a moderate-to-severe decrease (69% of predicted values), indicating the presence of significant restrictive lung defect. Only 1 of 10 children had severe airway obstruction. The baseline Crs was markedly decreased in part because of the presence of significant atelectasis. Crs increased with an average of 42% after repeated hyperinflation (deep sighs). There was no change in lung volume or function immediately before versus after completion of expansion thoracoplasty. FVC increased significantly over time, with an average rate of 26.8% per year, the rate of increase similar to that of healthy children of comparative ages. In terms of percent-predicted values, FVC did not change significantly between the baseline and last test, indicating that in most children studied, lung growth kept up with body growth. CONCLUSION: Although it is difficult to assess the extent of the efficacy without a proper or historical control group for comparison, the present study indicates that in children with severe thoracic insufficiency syndrome, the insertion of VEPTRs with multiple expansion thoracoplasties is beneficial over time, by allowing the lungs to expand with body growth without further deterioration in lung function.

Superior mesenteric artery syndrome in scoliosis surgery: weight percentile for height as an indicator of risk.

A retrospective analysis of charts identified cases of superior mesenteric artery (SMA) syndrome occurring after scoliosis surgery over a 23-year period. Despite numerous reports on this potentially fatal complication of scoliosis surgery, no method exists to stratify patients for risk of developing disease after spine surgery. A study of charts was performed to identify all cases of SMA syndrome occurring after scoliosis surgery from 1972 to 1995. An upper gastrointestinal study with findings specific for the syndrome was requisite for inclusion. Patients' weight and height at the time of diagnosis of SMA syndrome were recorded. Based on standard national data tables, a percentile for weight, percentile for height, and a weight percentile for height were derived for each patient. The syndrome occurred after posterior spinal fusion in six patients (three boys, three girls). The average weight percentile for height, available in five of the six patients, was 3%, significantly different from both age-matched controls in the general population and from age-matched controls undergoing posterior spinal fusion for adolescent idiopathic scoliosis. This study, the largest reported from a single institution, suggests that a weight percentile for height of 5% is the degree of asthenia that allows compromise of the duodenum. The percentile identifies patients at risk for SMA syndrome for the purposes of increasing postoperative vigilance for gastrointestinal complaints, decreasing the threshold for diagnostic workup, and guiding perioperative dietary supplementation.

Muscle-based gene therapy and tissue engineering for treatment of growth plate injuries.

Growth plate injuries may lead to a progressive angular deformity or longitudinal growth disturbance. The authors investigated the feasibility of gene therapy and tissue engineering based on autologous muscle-and adenoviral-mediated gene transfer of insulin-like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) to treat tibial physeal defects in rabbits. The medial half of the left proximal tibial growth plate was completely excised in 44 6-week-old New Zealand white rabbits. Four experimental groups were created: no treatment (I), autologous muscle interposition (II), autologous muscle interposition injected with adIGF-1 (III), and autologous muscle interposition injected with adBMP-2 (IV). Radiographic and histologic assessments were obtained postoperatively. Significant tibial shortening and a compact osseous bridge were observed in groups I and IV. Growth plates remained open in groups II and III. This experiment demonstrates that IGF-1 had a supportive effect on physeal chondrocytes, while BMP-2 caused increased osteogenic activity in the injured growth plates.

Valoración del incremento acetabular después de osteotomía innominada del iliaco: modelo experimental / An assessment of the acetabular increase after the innominate osteotomy of the iliac bone: experimental model

En 1915 Albee inició el tratamiento de la luxación congénita de la cadera comparando sus resultados con los reportados por Hoffa en 1890. A partir de este momento se inició una serie de publicaciones en la literatura anglosajona sobre osteotomías del iliaco. La forma en que describen el desplazamiento acetabular es con base en una evaluación radiográfica que sólo es bidimensional, y clínicamente en cadáver o paciente, en forma tridimencional, pero de manera subjetiva. En el año de 1976, George T. Rab describió los aspectos biomecánicos de la osteotomía de Salter; posteriormente, en 1978 Hansson reportó un caso clínico con valoración tridimensional con el uso de la radioesterofotogrametría (REFG) del desplazamiento acetabular después de la osteotomía del iliaco. El porcentaje de error en ambas técnicas es alto en forma cuantitativa, pero no en forma cualitativa. En esta investigación empleamos el método de la REFG, para determinar el desplazamiento acetabular en forma tridimensional, que consta de una jaula de calibración, marcadores radiopacos, dos placas radiográficas y, por último una pelvis, modelo de acetábulos displásicos tomado del catálogo de Sawbones. Los resultados fueron un desplazamiento del acetábulo después de la osteotomía innominada del iliaco en forma anterolateral y con desplazamiento medial de la pared posterior, lo cual condiciona una falta de cobertura posterior. El centro del acetábulo se desplaza en forma dista, posterior y medial. Concluimos que el método de REFG es eficaz para la valoración del desplazamiento acetabular en forma tridimencional, en el modelo experimental, tanto en forma cuantitativa como cualitativa.