Verena M. Schreiber

Anatomic Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction Flowchart

Anatomy is the foundation of orthopaedic surgery, and the advancing knowledge of the anterior cruciate ligament (ACL) anatomy has led to the development of improved modern reconstruction techniques that approach the anatomy of the native ACL. Current literature on the anatomy of the ACL and its reconstruction techniques, as well as our surgical experience, was used to develop a flowchart that can aid the surgeon in performing anatomic ACL reconstruction. We define anatomic ACL reconstruction as the functional restoration of the ACL to its native dimensions, collagen orientation, and insertion sites. A guideline was written to accompany this flowchart with more detailed information on anatomic ACL reconstruction and its pitfalls, all accompanied by relevant literature and helpful figures. Although there is still much to learn about anatomic ACL reconstruction methods, we believe this is a helpful document for surgeons. We continue to modify the flowchart as more information about the anatomy of the ACL, and how to more closely reproduce it, becomes available.

The anatomic approach to primary, revision and augmentation anterior cruciate ligament reconstruction

The anatomic approach is gaining popularity in anterior cruciate ligament (ACL) reconstruction. It is predominantly applied during primary ACL reconstruction. However, following the same principles as during primary surgery, the anatomic approach can also be applied during revision and augmentation surgery. This paper discusses the surgical technique for anatomic single- and double-bundle ACL reconstruction, for primary, revision and augmentation surgery. During primary reconstruction, the choice for single- or double-bundle reconstruction and graft size should be based on ACL insertion site and femoral intercondylar notch dimensions. When there is an isolated anteromedial (AM) or posterolateral (PL) bundle rupture, augmentation of a single-bundle can be performed while protecting the integrity of the intact bundle. Especially during revision surgery, there are many potential situations the surgeon may encounter when entering the knee. There are multiple possible solutions for all of these different situations leading to an anatomic end result. Three-dimensional computed tomography (CT) scanning should be used to evaluate the current tunnel positions and determine the operative strategy.

The timing of definitive fixation for major fractures in polytrauma—A matched-pair comparison between a US and European level I centres: Analysis of current fracture management practice in polytrauma

PURPOSE Early definitive stabilisation is usually the treatment of choice for major fractures in polytrauma patients. Modifications may be made when patients are in critical condition, or when associated injuries dictate the timing of surgery. The current study investigates whether the timing of fracture treatment is different in different trauma systems. MATERIALS AND METHODS Consecutive patients treated a Level I trauma centre were documented (Group US) and a matched-pair group was gathered from the German Trauma Registry (Group GTR). INCLUSION CRITERIA New Injury Severity Score (NISS)>16, >2 major fractures and >1 organ/soft tissue injury. The timing and type of surgery for major fractures was recorded, as were major complications. RESULTS 114 patients were included, n=57 Group US (35.1% F, 64.9% M, mean age: 44.1 yrs±16.49, mean NISS: 27.4±8.65, mean ICU stay: 10±7.49) and n=57 Group GTR (36.8% F, 63.1% M, mean age: 41.2 yrs±15.35, mean NISS: 29.4±6.88, mean ICU stay: 15.6±18.25). 44 (57.1%) out of 77 fractures in Group US received primary definitive fracture fixation compared to 61 (65.5%) out of 93 fractures in Group GTR (n.s.). The average duration until definitive treatment was comparable in all major extremity fractures (pelvis: 5 days±2.8 Group US, 7.1 days±9.6 Group GTR (n.s.), femur: 7.9 days±8.3 Group US, 5.5 days±7.9 (n.s.), tibia: 6.2 days±5.6 Group US, 6.2 days±9.1 Group GTR (n.s.), humerus: 5 days±3.7 Group US, 6.6 days±6.1 Group GTR (n.s.), radius: 6 days±4.7 Group US, 6.1 days±8.7 Group GTR (n.s.). CONCLUSION The current matched-pair analysis demonstrates that the timing of initial definitive fixation of major fractures is comparable between the US and Europe. Certain fractures are stabilised internally in a staged fashion regardless the trauma system, thus discounting previous apparent contradictions.

The use of blood vessel-derived stem cells for meniscal regeneration and repair.

PURPOSE Surgical repairs of tears in the vascular region of the meniscus usually heal better than repairs performed in the avascular region; thus, we hypothesized that this region might possess a richer supply of vascular-derived stem cells than the avascular region. METHODS In this study, we analyzed 6 menisci extracted from aborted human fetuses and 12 human lateral menisci extracted from adult human subjects undergoing total knee arthroplasty. Menisci were immunostained for CD34 (a stem cell marker) and CD146 (a pericyte marker) in situ, whereas other menisci were dissected into two regions (peripheral and inner) and used to isolate meniscus-derived cells by flow cytometry. Cell populations expressing CD34 and CD146 were tested for their multilineage differentiation potentials, including chondrogenic, osteogenic, and adipogenic lineages. Fetal peripheral meniscus cells were transplanted by intracapsular injection into the knee joints of an athymic rat meniscal tear model. Rat menisci were extracted and histologically evaluated after 4 wk posttransplantation. RESULTS Immunohistochemistry and flow cytometric analyses demonstrated that a higher number of CD34- and CD146-positive cells were found in the peripheral region compared with the inner region. The CD34- and CD146-positive cells isolated from the vascular region of both fetal and adult menisci demonstrated multilineage differentiation capacities and were more potent than cells isolated from the inner (avascular) region. Fetal CD34- and CD146-positive cells transplanted into the athymic rat knee joint were recruited into the meniscal tear sites and contributed to meniscus repair. CONCLUSIONS The vascularized region of the meniscus contains more stem cells than the avascular region. These meniscal-derived stem cells were multipotent and contributed to meniscal regeneration.

Regarding “Global Discrepancies in the Diagnosis, Surgical Management, and Investigation of Femoroacetabular Impingement”

Purpose: The purpose of this study was to review the global pattern of surgical management of femoroacetabular impingement (FAI), particularly in diagnosis, outcome measurement, and management. Methods: We performed a systematic search in duplicate for surgical studies addressing FAI published up to June 2013. Study parameters, including sample size, study location, surgical intervention technique, diagnostic imaging, outcome measures used, sex distribution, and level of evidence, were obtained. The number of trials and cumulative sample size were analyzed. The surgical interventions, sex distribution, outcome measures, and diagnostic imaging used were compared between geographic regions. Results: We identified 105 studies reporting surgical interventions for FAI. Most studies were completed in North America (52 studies, 3,629 patients) and in Europe (44 studies, 3,745 patients). Asia (3 studies, 49 patients) and Oceania (6 studies, 394 patients) had smaller contributions. There were no studies from South America or Africa. Most research performed in North America, Europe, and Oceania investigated arthroscopic FAI surgery (55% of studies) followed by surgical dislocation (33%), and miniopen (15%) and combined approaches (8%). Methods of diagnosis were consistent worldwide, with radiography being the mainstay of diagnosis (84% of studies). Case series were the most common type of study globally (75% of studies). Outcome measures varied by region; Harris hip scores were most common in North America, Oceania, and Asia, whereas Non-Arthritic Hip Scores and Western Ontario McMaster scores predominated in Europe. Conclusions: Global surgical trends for FAI show a predominance of North American and European studies, studies of lower level evidence, and inconsistent use of outcome measures. However, patterns of diagnostic imaging, sex proportions, and predominance of arthroscopic techniques are consistent worldwide. Future research should focus on development of reliable validated outcome measures and international collaboration to conduct high-quality research and improve our understanding of FAI diagnosis and management. Level of Evidence: Level IV, systematic review of Level I-IV studies.

Is There a Difference in Graft Motion for Bone-Tendon-Bone and Hamstring Autograft ACL Reconstruction at 6 Weeks and 1 Year?

Background: Bone–patellar tendon–bone (BTB) grafts are generally believed to heal more quickly than soft tissue grafts after anterior cruciate ligament (ACL) reconstruction, but little is known about the time course of healing or motion of the grafts within the bone tunnels. Hypothesis: Graft-tunnel motion will be greater in hamstring (HS) grafts compared with BTB grafts and will be less at 1 year than at 6 weeks. Study Design: Controlled laboratory study. Methods: Twelve patients underwent anatomic single-bundle ACL reconstruction using HS or BTB autografts (6 per group) with six 0.8-mm tantalum beads embedded in each graft. Dynamic stereo x-ray images were collected at 6 weeks and 1 year during treadmill walking and stair descent and at 1 year during treadmill running. Tibiofemoral kinematics and bead positions were evaluated. Graft-tunnel motion was based on bead range of motion during the loading response phase (first 10%) of the gait cycle. Results: During treadmill walking, there was no difference in femoral tunnel or tibial tunnel motion between BTB or HS grafts at 6 weeks (BTB vs HS: 2.00 ± 1.05 vs 1.25 ± 0.67 mm [femoral tunnel]; 1.20 ± 0.63 vs 1.27 ± 0.71 mm [tibial tunnel]), or 1 year (BTB vs HS: 1.62 ± 0.76 vs 1.08 ± 0.26 mm [femoral tunnel]; 1.58 ± 0.75 vs 1.68 ± 0.53 mm [tibial tunnel]). During stair descent, there was no difference in femoral or tibial tunnel motion between BTB and HS grafts at 6 weeks or 1 year. With running, there was no difference between graft types at 1 year. For all results, P values were > .05. Knee kinematics were consistent with the literature. Conclusion: During walking and stair descent, ACL reconstruction using suspensory fixation yielded no difference between graft types in femoral or tibial tunnel motion at 6 weeks or 1 year. All subjects were asymptomatic with knee kinematics similar to that of the literature. The significance of persistent, small (1 to 3 mm) movements at 1 year for healing or graft performance is unknown. Clinical Relevance: These study results may have significant implications for graft choice, rehabilitation strategies, and timing for return to sports.

MRI of the Patellofemoral Articular Cartilage

Patellofemoral pain is common and can be disabling [19, 49]. In the absence of severe trauma or anatomical abnormality, the cause is frequently unclear. Mechanical factors that increase forces across the joint resulting in cartilage degeneration with concomitant greater stress to the subchondral bone are considered to be important etiological factors.