The purpose of this study was to clarify the clinical behaviour, prognosis, and optimum treatment of dedifferentiated low-grade osteosarcoma (DLOS) diagnosed based on molecular pathology. We retrospectively reviewed 13 DLOS patients (six men, seven women; median age 32 years (interquartile range (IQR) 27 to 38)) diagnosed using the following criteria: the histological coexistence of low-grade and high-grade osteosarcoma components in the lesion, and positive immunohistochemistry of mouse double minute 2 homolog (MDM2) and cyclin-dependent kinase 4 (CDK4) associated with MDM2 amplification. These patients were then compared with 51 age-matched consecutive conventional osteosarcoma (COS) patients (33 men, 18 women; median age 25 years (IQR 20 to 38)) regarding their clinicopathological features.Aims
Patients and Methods
Flexion contracture sometimes occurs after primary total knee arthroplasty (TKA). In most cases, flexion contracture after TKA gradually improves over time. However, some severe cases require manipulation or revision surgery. We searched our clinical database for patients who underwent primary TKA at our institution between 2008 and 2015. By reviewing patient records, we identified three patients (one man and two women) with a severe flexion contracture 30° after primary TKA. Although all three patients gained more than 120° in flexion intraoperatively, they developed flexion contracture after discharge from our institution. We performed manipulation under anaesthesia (MUA) for all three cases several months later. The two female patients had improved range of motion (ROM) right after the manipulation. However, one of them regained flexion contracture 1 year after the MUA. We report the details of the male patient, who had the worst flexion contracture (−60°). An 80-year-old man had right knee osteoarthritis. His history indicated only hypertension. The right knee ROM before the TKA was −20° extension and 135° flexion. His radiographs showed advanced-stage osteoarthritis. We performed cemented TKA (posterior stabiliser design). Three weeks after the operation, his right knee pain improved. The right knee ROM was −10° extension and 100° flexion just before discharge. However, he returned to our institution because of right knee pain and flexion contracture 31 months after the surgery. The flexion contracture gradually worsened without any trauma. When he returned, the right knee ROM was −60° extension and 135° flexion. Manipulation under general anaesthesia was not effective. Therefore, we performed revision TKA immediately. We excised the scar tissue of the posterior knee joint. Then, we shortened the distal femoral end by 1 cm and reduced the size of the femoral component. After the operation, the right knee ROM was improved to −10° flexion and 130° extension. The reported prevalence of stiffness after TKA was from 1.3% to 13%. Although the deleterious effects of persistent flexion contractures > 15° is well understood, whether they resolve with time or need surgical intervention is controversial. MUA is generally the initial option for patients with flexion contractures, with the possibility of some improvement. If severe flexion contracture remains after manipulation, revision TKA, which may be considered as a useful treatment option, should be considered.
Pelvic osteotomy such as Chiari osteotomy and rotational acetabular osteotomy (RAO) have been used successfully in patients with developmental dysplasia of the hip (DDH). However, some patients are forced to undergo total hip arthroplasty (THA) because of the progression of osteoarthritis. THA after pelvic osteotomy is thought to be more difficult because of altered anatomy of the pelvis. We compared six THAs done in dysplastic hips after previous pelvic osteotomy between 2008 and 2015 with a well-matched control group of 20 primary procedures done during the same period. Six THAs for DDH after previous Pelvic osteotomy (three Chiari osteotomies and three RAOs) were compared with 20 THAs for DDH without previous surgery. The patients were matched for age, sex, and BMI. Minimum follow-up for both groups of patients was one year (range, 12–79 months and 12–77 months, respectively). The average interval from pelvic osteotomy to total hip arthroplasty was 19.8 years (range 12–26 years). Clinical and Radiological evaluations were performed.Introduction
Materials and methods
Proximal femoral osteotomy is an attractive joint preservation procedure for osteonecrosis of the femoral head. The purpose of this study was to investigate the cause of failure of proximal femoral osteotomy in patients with osteonecrosis of the femoral head. Between 2008 and 2014, proximal femoral osteotomy was performed by one surgeon in 13 symptomatic hips. Ten trans-trochanteric rotational osteotomies (anterior: 7, posterior: 3) and 3 intertrochanteric curved varus osteotomy were performed. Of the patients, 9 were male and 1 was female, with a mean age at surgery of 36.9 years (range, 25–55 years). The mean postoperative follow-up period was 38 months (range, 12–72 months). Three patients (4 hips) had steroid-induced osteonecrosis, and 7 (9 hips) had alcohol-associated osteonecrosis. At 6 postoperative weeks, partial weight bearing was permitted with the assistance of 2 crutches. At more than 6 postoperative months, full weight bearing was permitted. Patients who had the potential to achieve acetabular coverage of more than one-third of the intact articular surface on preoperative hip radiography, computed tomography, and magnetic resonance imaging were considered suitable for this operation. A clinical evaluation using the Japanese Orthopaedic Association (JOA) scoring system and a radiologic evaluation were performed. Clinical failure was defined as conversion to total hip arthroplasty (THA) or progression to head collapse and osteoarthritis. The 13 hips were divided into two groups, namely the failure and success groups.Purpose
Patients and Methods
Rotational malalignment of the femoral component still causes patellofemoral complications that result in failures in total knee arthroplasty (TKA). To achieve correct rotational alignment, a couple of anatomical landmarks have been proposed. Theoretically, transepicondylar axis has been demonstrated as a reliable rotational reference line, however, intraoperative identification of the transepicondylar axis is challenging in some cases. Therefore, surgeons usually estimate the transepicondylar axis from posterior condylar axis (PCA) using twist angle determined by the preoperative X-rays and CT. While PCA is the most apparent landmark, radiographs are not able to detect posterior condylar cartilage. In most osteoarthritic knees, the cartilage thickness of the posterior condyle is different between medial and lateral condyles. The purpose of this study is to evaluate the effect of the posterior condylar cartilage on rotational alignment of the femoral component in large number of arthritic patients. Furthermore, we investigated whether the effect of posterior condylar cartilage is different between osteoarthritis (OA) and rheumatoid arthritis (RA). Ninety-nine OA knees and 36 RA knees were included. Detailed information is summarized in Table 1. All cases underwent TKA using navigation system. The institutional review board approved the study protocol and informed consent was obtained from each participants. To evaluate the effect of posterior condylar cartilage, we measured two different condylar twist angle (CTA) using navigation system and intraoperative fluoroscopy-based multi-planner reconstruction (MPR) images obtained by a mobile C-arm. To uniform the SEA in two different measuring systems, we temporary inserted a suture anchors in medial and lateral prominence. The CTA that does not include the posterior condylar cartilage (MPR CTA) is evaluated on MPR images and the CTA that does include the posterior condylar cartilage (Navi. CTA) is calculated by navigation system. The difference between these two angles corresponds to the effect of posterior condylar cartilage on the rotation of the femoral component (Fig. 1). The paired or unpaired t test was used to compare the obtained data. The statistics were performed using GraphPad Prism 6. A P value of 0.05 or less is considered as a significant difference.Objective
Methods
Recently, there are increasing literatures of the in vivo kinematics of total knee arthroplasty (TKA). Those previous studies have been reported in regard of either intra-operative kinematics or post-operative kinematics. However, the direct correlation between intra- and post-operative kinematics of TKA has not been revealed. There are no evidences that intra-operative kinematics can lead to post-operative kinematics. The purpose of this study is to verify the direct correlation between intra- and post-operative kinematics of TKA.Introduction
Purpose
The aim of this study is to verify the intra-rater and inter-rater reliability of intra-operative kinematics by hand in TKA using a computer assisted image-free navigation system. Total knee arthroplasty (TKA) was performed on the knees of twelve (12) patients with knee navigation by one surgeon. Patients were divided into two groups: Group A included six knees that were operated on with assistant A (senior joint surgeon); and Group B included the other six knees that were operated on with assistant B (resident). For each knee, axial rotation was evaluated three times by the operator and the assistant using a navigation system at 30°, 60°, 90°, 120° passive flexions by hand. Intra-class correlation coefficients (ICC) were calculated for each evaluation to examine intra-rater and inter-rater reliability.Introduction
Material and Methods
