Multivariate analysis of varus after Oxford unicompartmental knee arthroplasty / 北京大学学报(医学版)

OBJECTIVE@#To analyze the preoperative influencing factors of varus after Oxford unicompartmental knee arthroplasty.@*METHODS@#A total of 660 patients (767 knees) undergoing Oxford unicompartmental knee arthroplasty in adult joint reconstruction surgery department of Beijing Jishuitan Hospital from January 2018 to December 2019 were retrospectively analyzed. Inclusive criteria: diagnosis was osteoarthritis, single compartment lesions in the medial side of the knee; preoperative flexion deformity was less than 10°, active range of motion was greater than 90°; preoperative X-ray full-length images of both lower limbs showed less than 15° varus (Noyes method); anterior cruciate ligament was well functioned, The cartilage of lateral compartment of knee joint was intact.@*EXCLUSION CRITERIA@#combined with other inflammatory arthropathy; combined with extraarticular deformity; previous knee surgery history. The average age of the patients was (64.4±8.1) years, including 153 males and 497 females. The degree of post-operative varus was measured with Noyes method. The total patients were divided into varus group (Noyes≥3 °) and normal group (Noyes < 3 °). Gender, age, body mass index (BMI), range of motion (ROM), preoperative flexion deformity (FD), American Knee Society pain score (AKS) and American Knee Society function score (AKS function) were recorded. The standard anteroposterior and lateral X-ray films of knee joint and full-length lower extremity kinematic line films were taken by Sonialvision Safine Ⅱ (Shimadzu, Japan) multi-function digital tomography system. The image was measured by picture archiving and communication system (PACS). The following angles were measured preoperative Noyes angle, lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA) and joint line converge angle (JLCA) were measured and analyzed.@*RESULTS@#Gender(P=0.346), operative side (P=0.619), age (P=0.746), BMI (P=0.142), preoperative ROM (P=0.102), preoperative knee pain score (P=0.131) and functional score (P=0.098) were not risk factors for postoperative varus. The influencing factors of postoperative varus were preoperative MPTA < 84 ° (P= 0.018, OR= 3.712, 95%CI: 1.250-11.027), preoperative Noyes > 5°(P=0.000, OR= 3.105, 95%CI: 1.835-5.254), preoperative FD > 5° (P= 0.001, OR=1.976, 95%CI: 1.326-3.234). Pre-operative LDFA (P=0.146) and preoperative JLCA (P= 0.709) had no significant effect on postoperative kinematic line.@*CONCLUSION@#Patients with severe preoperative varus, especially those with varus deformity mainly from the tibial side, and those with preoperative flexion deformity are more prone to get varus lower extremity kinematic line after Oxford unicompartmental knee arthroplasty.

Etiological and clinical analysis of osteonecrosis of the femoral head in Chinese patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Many potential causative factors are related to the initiation and progression of osteonecrosis of the femoral head. The aim of this research was to investigate the etiology and clinical features of osteonecrosis of the femoral head in Chinese patients.</p><p><b>METHODS</b>From January 1990 to July 2011, 643 cases of osteonecrosis of the femoral head were investigated retrospectively to analyze the potential causative factors, age, gender, latency period, time from the onset of pain to diagnosis, and Association Research Circulation Osseous stage.</p><p><b>RESULTS</b>Of 643 cases, 315 cases were bilateral and 328 cases were unilateral, with an average age of (47.55 ± 15.27) years. In the steroid-induced group, the average age at symptom onset was (41.80 ± 15.47) years, and the median duration from taking steroid to the onset of pain was 36 months. The underlying diseases in the steroid-induced osteonecrosis of the femoral head group consisted of autoimmune and other diseases, of which systemic lupus erythematosus was the most common. In the alcohol-induced group, the average age at onset of symptoms was (48.06 ± 11.90) years and the median time of habitual alcohol use was 240 months. In the traumatic group, the average age was (51.43 ± 14.23) years and the median time from trauma to the onset of pain was 20 months. In the idiopathic group, the average age was (50.33 ± 15.88) years. Of the total of 958 hips, 647 were at stage III or IV. The stage at diagnosis was earlier in the steroid-induced group than in the alcohol-induced, traumatic, or idiopathic groups.</p><p><b>CONCLUSIONS</b>Steroid use is the most common cause for osteonecrosis of the femoral head in this study. The age at diagnosis, time from the onset of pain to diagnosis, and stage were significantly earlier in the steroid-induced group.</p>