Outcomes of Operatively Treated Acute Knee Dislocations

Knee dislocation is a complex and rare injury often presenting in the context of high velocity trauma. The aim of this study is to establish the subjective outcomes of surgically treated knee dislocations. A total of 20 knees dislocations treated by open repair were reviewed. Their progress and outcomes were assessed by using a modified Lysholm score questionnaire. Data was obtained on patient demographics, details of injury, investigation, treatment, rehabilitation, 24 months objective outcome and subjective outcomes. Six patients had a vascular deficit and six had neurological deficits. The median range of motion was 0°-100°. Patients with an initially lower pre-injury level of function were able to return an activity level comparable to their pre-injury status. 22% of competitive athletes retuned to competitive sports. 38% of patients undertaking heavy activity returned to comparable pre-injury level of activity and 67% of patients undertaking moderate level of activity before injury returned to a comparable level after repair. 68% regularly had problems running, 70% problem squatting, 40% swelling and 42% problem with stairs. Most patients however did not have locking of the knee or problems with knees giving way. Patients pain scores decreased over time to an acceptable level. Despite the severity of the injury, majority of patients achieved a satisfactory outcome, although none of the patients reached the same level of function as before the injury. 80% of the patients were satisfied with their outcome. All dissatisfied patients suffered postoperative complications

Wild chimpanzees modify modality of gestures according to the strength of social bonds and personal network size

Primates form strong and enduring social bonds with others and these bonds have important fitness consequences. However, how different types of communication are associated with different types of social bonds is poorly understood. Wild chimpanzees have a large repertoire of gestures, from visual gestures to tactile and auditory gestures. We used social network analysis to examine the association between proximity bonds (time spent in close proximity) and rates of gestural communication in pairs of chimpanzees when the intended recipient was within 10 m of the signaller. Pairs of chimpanzees with strong proximity bonds had higher rates of visual gestures, but lower rates of auditory long-range and tactile gestures. However, individual chimpanzees that had a larger number of proximity bonds had higher rates of auditory and tactile gestures and lower rates of visual gestures. These results suggest that visual gestures may be an efficient way to communicate with a small number of regular interaction partners, but that tactile and auditory gestures may be more effective at communicating with larger numbers of weaker bonds. Increasing flexibility of communication may have played an important role in managing differentiated social relationships in groups of increasing size and complexity in both primate and human evolution

Current concepts in acute knee dislocation: the missed diagnosis?

Traumatic knee dislocation is a serious and potentially limb threatening injury that can be easily missed if meticulous history and examination have not been employed. Neurovascular injuries are common in this condition, and due diligence should be given to their thorough evaluation at time of secondary survey so as to avoid complications such as ischaemia, compartment syndrome and eventual amputation. There is growing evidence in the literature that morbid obesity is associated with low energy knee dislocation, therefore this should be considered when assessing this cohort of patients presenting with an acute knee injury. Early operative intervention especially with multi ligaments involvement is the preferable strategy in the management of this acute injury. Controversy exists whether to reconstruct or repair damaged structures, and whether to adopt a one stage or two stage reconstruction of the cruciate ligaments. Early rehabilitation is important and essential to achieve satisfactory outcomes. This article is an evidence-based overview of this rare but devastating injury

Double-bundle PCL and Posterolateral Corner Reconstruction Components are Codominant

A more complete biomechanical understanding of a combined posterior cruciate ligament and posterolateral corner knee reconstruction may help surgeons develop uniformly accepted clinical surgical techniques that restore normal anatomy and protect the knee from premature arthritic changes. We identified the in situ force patterns of the individual components of a combined double-bundle posterior cruciate ligament and posterolateral corner knee reconstruction. We tested 10 human cadaveric knees using a robotic testing system by sequentially cutting and reconstructing the posterior cruciate ligament and posterolateral corner. The knees were subjected to a 134-N posterior tibial load and 5-Nm external tibial torque. The posterior cruciate ligament was reconstructed with a double-bundle technique. The posterolateral corner reconstruction included reattaching the popliteus tendon to its femoral origin and reconstructing the popliteofibular ligament. The in situ forces in the anterolateral bundle were greater in the posterolateral corner-deficient state than in the posterolateral corner-reconstructed state at 30° under the posterior tibial load and at 90° under the external tibial torque. We observed no differences in the in situ forces between the anterolateral and posteromedial bundles under any loading condition. The popliteus tendon and popliteofibular ligament had similar in situ forces at all flexion angles. The data suggest the two bundles protect each other by functioning in a load-sharing, codominant fashion, with no component dominating at any flexion angle. We believe the findings support reconstructing both posterior cruciate ligament bundles and both posterolateral corner components