Novel method of measuring patellar height ratio using a distal femoral reference point

Purpose  

Patellar height is an important factor in patellar tracking and alters the force of the patellofemoral joint reaction. Several methods for measuring patellar height ratio have been described, with no single method recognised as a gold standard. This study developed a new measurement method using a distal femoral reference, where the normal values of measurement are unaffected by varying angles of knee flexion.     

Revision Hip Arthroplasty Using a Modular,Cementless Femoral Stem: Intermediate-Term Follow-Up

Background

Modular femoral stem provides flexibility in femoral reconstruction, ensuring improved “fit and fill”. However, there are risks of junction failure and corrosion, as well as cost concerns in the use of modular femoral stems.

Elevated Body Mass Index Is Associated With Early Total Knee Revision for Infection

Background

Obesity affects over half a billion people worldwide, including one-third of men and women in the United States. Obesity is associated with higher postoperative complication rates after total knee arthroplasty (TKA). It remains unknown whether obese patients progress to revision TKA faster than nonobese patients.

Increased cerebral blood flow on arterial spin labeling magnetic resonance imaging can localize to seizure focus in newborns: A report of 3 cases

Arterial spin labeling (ASL) magnetic resonance imaging (MRI) can assess cerebral blood flow (CBF) without using radiolabeled tracers. It is unknown whether regional increases in CBF on ASL MRI correlate with seizure location in newborns. We report 3 newborns with focal seizures localized on continuous video electroencephalogram (cEEG), anatomical brain MRI, and ASL MRI. Each patient underwent pseudocontinuous ASL with segmented 3‐dimensional fast spin echo readout as part of standard care. Case 1 is a term male infant presenting with left temporal status epilepticus and recurrent cEEG seizures from an idiopathic large left intraventricular hemorrhage. ASL images demonstrated left mesial temporal lobe increased CBF. Case 2 is a late preterm male infant presenting with recurrent cEEG seizures due to focal right megalencephaly. Ictal EEG and ASL images coincided with the focal dysplasia. Case 3 is a dysmorphic term female infant with nonconvulsive partial status epilepticus identified by focal increased CBF of the left temporal lobe on ASL images. The area of increased CBF was within an area of extensive left hemisphere dysplasia. To our knowledge, this is the first report of regional increases in CBF on ASL MRI correlating with ictal cEEG in newborns.     

Neutralizing antibodies against adeno-associated virus examined prospectively in pediatric patients with hemophilia

Recombinant adeno-associated virus (rAAV) is a promising gene delivery vector and has recently been used in patients with hemophilia. One limitation of AAV application is that most humans have experienced wild-type AAV serotype 2 exposure, which frequently generates neutralizing antibodies (NAbs) that may inhibit rAAV2 vector transduction. Employing alternative serotypes of rAAV vectors may circumvent this problem. We investigated the development of NAbs in early childhood by examining sera gathered prospectively from 62 children with hemophilia A, participating in a multi-institutional hemophilia clinical trial (the Joint Outcome Study). Clinical applications in hemophilia therapy have been suggested for serotypes AAV2, AAV5 and AAV8, therefore NAbs against these serotypes were serially assayed over a median follow-up of 4 years. NAbs prevalence increased during early childhood for all serotypes. NAbs against AAV2 (43.5%) were observed more frequently and at higher titers compared with both AAV5 (25.8%) and AAV8 (22.6%). NAbs against AAV5 or AAV8 were rarely observed in the absence of co-prevalent and higher titer AAV2 NAbs, suggesting that NAbs to AAV5 and AAV8 were detected following AAV2 exposure due to partial cross-reactivity of AAV2-directed NAbs. The results may guide rational design of clinical trials using alternative AAV serotypes and suggest that younger patients who are given AAV gene therapy will benefit from the lower prevalence of NAbs.     

Medial proximal tibial angle after medial opening wedge HTO: A retrospective diagnostic test study

Background:

Medial proximal tibial angle (MPTA) is the commonly used angle, which is simply measured from the knee radiographs. It can determine the correction angle in medial opening wedge high tibial osteotomy (MOWHTO). The hypothesis of our study is that post-osteotomy MPTA can predict the change in correction angle, and we aimed to determine the optimal MPTA with which to prevent recurrent varus deformity after MOWHTO.

Materials and Methods:

Between January 2002 and April 2010, radiographs of 59 patients, who underwent 71 MOWHTOs using the locking-compression osteotomy plates without bone grafts, were evaluated for the change of the MPTA. The MPTA was measured preoperatively and one and twelve months postoperatively. The changes of MPTA between one and twelve months were classified into valgus, stable, and varus change. The predicting factors were analyzed using analysis of variance (ANOVA) and Bonferroni multiple comparisons. The receiver operating characteristic (ROC) curve was used to find out the cut off point for preventing the recurrent varus deformity.

Results:

The overall preoperative, and one and twelve month postoperative MPTA values were 84.4 ± 2.4°, 97.2 ± 4.1°, and 96.3 ± 3.6°, respectively. Between one and twelve months, 39 knees displayed reduced varus change (–2.8 ± 2.1°), 18 knees displayed no change, and 14 knees displayed a greater valgus change (+2.9 ± 2.1°). The best factor for predicting these changes was the one month MPTA value (P = 0.006). By using the ROC curve, a one month MPTA of 95° was analyzed as the cut off point for preventing the recurrent varus deformity. With MPTA ≥95°, 92.3% of the osteotomies exhibited stable or varus change and 7.7% exhibited valgus change. However, with MPTA <95°, 47.4% exhibited stable or varus change and 52.6% exhibited valgus change (P < 0.001, odds ratio = 13.3).

Conclusion:

The postoperative MPTA can be used to predict the change in correction angle and an MPTA of at least 95° is the crucial angle with which to prevent recurrent varus deformity.