On a total hip arthroplasty, there is a complication – the intraoperative proximal femoral fracture – which happens more often than it should and it can affect the recovery of the patient. A recent study tried to find the risk factors for this type of complication, the highest risk groups and minimize the incidence on this problem.
This study case included 904 primary cementless surgical procedures in total hip arthroplasty, on 769 patients, between 2009 and 2015. On this group, there were 24 intraoperative proximal femoral fractures, about 2,65% of the cases.
Several types of analysis were made in order to identify the risk factors for fractures on the total hip arthroplasty.
A primary total hip arthroplasty can relieve the patients pain and helps them to recover the hip function. With the aging of the population, the incidence on the intraoperative proximal femoral fracture has increased. These complications occur mostly during the process of the femoral canal broaching or implant insertion while you are attempting to obtain a tight press fit. If the fixation fails, it can lead to a fracture displacement and the loss of the femoral stem, leading the patient to another surgery.
The study used patients’ records and x-rays to analyze the annual incidence and risk factors for intraoperative proximal fracture in total hip arthroplasty. It was asked to all the patients to do a C-arm radiography to determine if there were intraoperative fractures that were not detected during surgery – of the 24 patients identified with intraoperative fractures, 9 were male patients and 15 were female patients.
The risk factors for this fracture were calculated by univariate analysis (chi-square test, analysis of variance, and Student’s t test) along with multivariate analysis.
The authors of this study obtained all the information about the patients’ sex, diagnosis of osteoarthritis, operations on the hip, type of implants, alcohol consumption, age and body mass.
In order to evaluate the anatomy and the morphologic features of the proximal femur, Noble classification, Dorr classification, and Metaphyseal-Diaphyseal Index, were used in every case.
The Noble classification was used to describe the shape of the proximal femur according to the canal flare index, which defines a result less than 3.0 as a stovepipe-shaped canal, a 3.0 to 4.7 as a normal canal and a 4.8 to 6.5 result as a champagne flute-shaped canal.
The Dorr classification, appoints 3 distinct patterns in the proximal femur based in two variants – the shape and bone structure. The first pattern has thick medial and lateral cortices on anteroposterior radiographs and a large posterior cortex on lateral x-rays. The second pattern exhibits bone loss from the medial cortex, especially the posterior cortex. The third pattern has virtually lost the medial and posterior cortices; in addition, the anterior and posterior cortices are thinned and appear fuzzy on lateral x-rays.
The Metaphyseal-Dyphyseal classification was used to describe two variants – the bone quality and morphologic features to predict suboptimal femoral morphologic features and the high chance of finding a periprosthetic fracture in osteoporotic femurs of poor bone quality.
The results showed that 805 of the total hip arthroplasties were performed with Synergy stems and another 99 were performed with Corail stems – 16 patients who underwent through the Synergy stems, were diagnosed with proximal femoral fractures and only 8 of the surgeries performed with Corail stems had complications.
A great part of the research has shown that to be a female represents one of the main risks for this type of surgery, mainly because of the osteoporosis and remaining structural bone.
The treatment for primary intraoperative proximal femoral fracture depends on the fracture location and the implant stability.The surgeons must pay attention to the stems they insert in their patients. Based on this study, the stem has a lot more chances to develop this kind of fractures, so re-operative templating is highly recommended.