Radiographic parameter-driven decision tree reliably predicts aseptic mechanical failure of compressive osseointegration fixation.

Background and purpose - Compressive osseointegration fixation is an alternative to intramedullary fixation for endoprosthetic reconstruction. Mechanical failure of compressive osseointegration presents differently on radiographs than stemmed implants, therefore we aimed to develop a reliable radiographic method to determine stable integration.Patients and methods - 8 reviewers evaluated 11 radiographic parameters from 29 patients twice, 2 months apart. Interclass correlation coefficients (ICCs) were used to assess test-retest and inter-rater reliability. We constructed a fast and frugal decision tree using radiographic parameters with substantial test-retest agreement, and then tested using radiographs from a new cohort of 49 patients. The model's predictions were compared with clinical outcomes and a confusion matrix was generated.Results - 6 of 8 reviewers had non-significant intra-rater ICCs for ≥ one parameter; all inter-rater ICCs were highly reliable (p < 0.001). Change in length between the top of the spindle sleeve and bottom of the anchor plug (ICC 0.98), bone cortex hypertrophy (ICC 0.86), and bone pin hypertrophy (ICC 0.81) were used to create the decision tree. The sensitivity and specificity of the training cohort were 100% (95% CI 52-100) and 87% (CI 74-94) respectively. The decision tree demonstrated 100% (CI 40-100) sensitivity and 89% (CI 75-96) specificity with the test cohort.Interpretation - A stable spindle length and at least 3 cortices with bone hypertrophy at the implant interface predicts stable osseointegration; failure is predicted in the absence of bone hypertrophy at the implant interface if the pin sites show hypertrophy. Thus, our decision tree can guide clinicians as they follow patients with compressive osseo-integration implants.

Headguard use in combat sports: position statement of the Association of Ringside Physicians.

Headguard use is appropriate during some combat sports activities where the risks of injury to the face and ears are elevated. Headguards are highly effective in reducing the incidence of facial lacerations in studies of amateur boxers and are just as effective in other striking sports. They should be used in scenarios - especially sparring prior to competitions - where avoidance of laceration and subsequent exposure to potential blood-borne pathogens is important. Headguards are appropriate where avoidance of auricular injury is deemed important; limited data show a marked reduction in incidence of auricular injury in wrestlers wearing headguards.Headguards should not be relied upon to reduce the risk of concussion or other traumatic brain injury. They have not been shown to prevent these types of injuries in combat sports or other sports, and human studies on the effect of headguards on concussive injury are lacking. While biomechanical studies suggest they reduce linear and rotational acceleration of the cranium, changes in athlete behavior to more risk-taking when wearing headguards may offset any risk reduction. In the absence of high-quality studies on headguard use, the Association of Ringside Physicians recommends that further research be conducted to clarify the role of headguards in all combat sports, at all ages of participation. Furthermore, in the absence of data on gender differences, policies should be standardized for men and women.

Compressive osseointegration for endoprosthetic reconstruction.

This review summarizes the biomechanical concepts, clinical outcomes and limitations of compressive osseointegration fixation for endoprosthetic reconstruction. Compressive osseointe - gration establishes stable fixation and integration through a novel mechanism; a Belleville washer system within the spindle applies 400-800 PSI force at the boneimplant interface. Compressive osseointegration can be used whenever standard endoprosthetic reconstruction is indicated. However, its mode of fixation allows for a shorter spindle that is less limited by the length of remaining cortical bone. Most often compressive osseointegration is used in the distal femur, proximal femur, proximal tibia, and humerus but these devices have been customized for use in less traditional locations. Aseptic mechanical failure occurs earlier than with standard endoprosthetic reconstruction, most often within the first two years. Compressive osseointegration has repeatedly been proven to be non-inferior to standard endoprosthetic reconstruction in terms of aseptic mechanical failure. No demographic, device specific, oncologic variables have been found to be associated with increased risk of aseptic mechanical failure. While multiple radiographic parameters are used to assess for aseptic mechanical failure, no suitable method of evaluation exists. The underlying pathology associated with aseptic mechanical failure demonstrates avascular bone necrosis. This is in comparison to the bone hypertrophy and ingrowth at the boneprosthetic interface that seals the endosteal canal, preventing aseptic loosening.