A pilot agreement study of a new classification system for Peri-implant femoral fractures.

BACKGROUND: Peri-implant fractures occur in association with an implant, used to treat a previous injury that is still attached to the bone. We recently published a proposal for a classification system for peri-implant femoral fractures [Videla-Cés, Injury,2019]. AIM: To assess the agreement of our classification system for peri-implant femoral fractures among a group of future users of said classification system. METHODS: A prospective, multicentre, international agreement pilot study was conducted among a group of independent traumatologists/orthopaedic surgeons (evaluators): senior (a minimum of 10 years' experience) and junior (in fourth or fifth training year). A set of 30 radiographs of peri-implant femoral fractures were selected (stratified into 3 levels of difficulty: low, medium and high). Each evaluator interpreted the radiographs on 2 different occasions separated by a period of one month and in a different order each time. The level of difficulty was masked from the evaluators and they had one week to classify the radiographs each time. Logistic regression and Cohen's kappa coefficient (κ) and its 95% confidence interval (95%CI) were used to assess the accuracy and agreement, both intra- and inter-evaluator. Between senior and junior surgeons was performed an exploratory analysis. RESULTS: 35 traumatologists/orthopaedic surgeons (17 senior and 18 junior) from 16 tertiary hospitals from 4 countries acted as evaluators. The accuracy, percentage of correct classifications (2 digits and 3 letters), in the first and second evaluation was: 56% (95%CI: 53-59%) and 55% (95%CI: 51-57%), respectively. (insert space) Negligible differences were found between junior and senior evaluators (first evaluation, OR: 1.46, 95%CI: 0.82-2.61, p-value: 0.199; second evaluation, OR: 1.06, 95%CI: 0.56-2.00, p-value: 0.860). (insert space) Both medium and low radiograph difficulty were associated with a lower probability of an incorrect classification compared with those of high difficulty (first evaluation, OR: 7.60, 95%CI: 5.24-11.05, p-value: <0.001; OR: 14.15, 95%CI: 9.12-21.96, p-value: <0.001, respectively; second evaluation, OR: 7.11, 95%CI: 4.88-10.38, p-value: <0.001, OR: 15.28, 95%CI: 9.77-23.89, p-value: <0.001). (insert space) The kappa for intra-observer agreement between the first and second evaluation was: 0.66, 95%CI: 0.63, 0.69. The kappa for inter-observer agreement considering all 30 radiographs was: 0.40, 95%CI: 0.40, 0.41 in the first evaluation and 0.39, 95%CI: 0.39, 0.40 in the second evaluation. CONCLUSION: The proposed classification for peri-implant femoral fractures may be useful and user-friendly. Future studies are needed to assess the how clinically useful this classification system may be (the third phase in the validation process).

Proposal for the classification of peri-implant femoral fractures: Retrospective cohort study.

Background Peri-implant fractures occur in association with an implant used to treat a previous injury and that is still attached to the bone. Peri-implant fractures are considered to be relatively "new" fractures and they lack any classification system that is accepted in practice. Generally, the fracture classification systems currently used in our clinical practice were not developed or validated using rigorous scientific evaluation methods. Aim To provide data for a proposed classification of peri-implant femoral fractures. Methods This is an international and multicentre study (12 centres) based on a cohort of consecutive peri-implant fractures with the criterion being: a fracture in any segment of the femur in association with previously-used osteosynthesis material, whether a nail, plate or screws. A proposed system for the classification was tested, based on a topographical classification using alphanumeric coding, following a similar nomenclature to that explained in the "Vancouver-Classification-for-Total-Hip-Arthroplasty-Periprosthetic-Fractures", and classified according to whether the implant is a nail, a screw or a plate, and the location of the fracture in relation to the original implant and the affected femoral segment. The study coordinator performed the first classification exercise, which was discussed subsequently for the study coordinator group to reach a consensus. A descriptive analysis of the fractures was produced. The proportion of peri-implant femoral fractures was estimated, and 95% confidence interval (95%CI) was calculated. Results Between January 2013 and December 2016, data on a total of 143 peri-implant femoral fractures were collected. Only 5 (3.5%) fractures had to be discussed to reach a consensus. The most common peri-implant femoral fractures were located at the diaphyseal segment (#32) and associated with nails or plates: 51%, 73/143, 95%CI:43-59%; at the proximal segment (#31): 39%, 56/143, 95%CI:32-47%; and at the distal femoral segment (#33): 10%, 14/143, 95%CI:6-16%. The highest proportion of peri-implant femoral fractures corresponded to #31-AN (trochanteric and neck area) and #32-CNP (diaphysis fractures distant from the implant, often distal and spiral). Conclusion The proposed classification for peri-implant femoral fractures appears to be useful and easy to accomplish. Future studies will be necessary to validate it and demonstrate the effectiveness of its application in clinical practice.

A retrospective cohort study of concomitant ipsilateral extra-capsular and intra-capsular fractures of the proximal femur. Are they casual findings or an undervalued reality?

BACKGROUND: Fractures of the proximal femur constitute a major public health problem, with an annual incidence in Spain of 7.6 cases per 1000 inhabitants over 65 years of age. Hip fractures are frequent in elderly patients, related to osteoporosis and with low energy trauma, which means that they can be considered a geriatric syndrome. Simultaneous ipsilateral extra- and intra-articular hip fractures are considered as very rare are, and generally speaking, classified as extra- or intra-capsular fractures. Moreover, there is no consensus with regard to treatment of these concomitant fractures. AIM: To estimate the incidence of concomitant ipsilateral extra- and intra-capsular fractures of the proximal femur, and to describe the diagnostic process and the clinical characteristics of these concomitant fractures. PATIENTS AND METHODS: Retrospective cohort study of patients with hip fractures. The incidence of combined extra- and intra-capsular fractures was estimated, a confidence interval of 95% (95%CI) was calculated and a descriptive analysis was drawn up. RESULTS: Between May 2010 (the date on which the Orthopaedic and Trauma Surgery Department of our new Hospital began the surgical activity) and December 2016, 33 (median age, 86 years-old) of the 2625 hip fractures were classified as simultaneous extra- and intra-capsular ipsilateral fractures. The overall cumulative incidence was of 1.3% (95%CI:0.9-1.8%). In 32 (97%) of the patients, the fracture was a consequence of a low energy trauma (ground level fall), while the remainder was due to a medium energy trauma (skating). In all cases the two fracture lines seem to be independent of each other, which suggests different mechanisms of injury from that of isolated subcapital or intrertrochanteric fracture. CONCLUSION: The incidence of concomitant ipsilateral extra- and intra-capsular fractures of the proximal femur must be taken into account in patients over 65 years of age. It is clinically relevant to identify these concomitant fractures in order to arrive at a correct diagnosis, which will facilitate preoperative planning and the choice of the best treatment to achieve a better outcome. Misdiagnosis may cause further problems, such as fixation failures, disability and, in a worst case scenario, an increased risk of death. Therefore, a good and complete preoperative study is important, along with both good quality X-ray projections and 2D and 3D Ct-Scans in case of doubt.