ABSTRACT
Patellofemoral instability, by definition, is a condition where the patella bone pathologically disarticulates out from the patellofemoral joint, either through subluxation or complete dislocation. The overall incidence of patellofemoral instability ranges between 5.8 and 29 per 100,000. Over time, patients with patellar instability can have debilitating pain, limitations in basic function, and long-term arthritis.Current Concepts: Risk factors for patellofemoral instability include trochlear dysplasia, patella alta, increased tibial tubercle-to-trochlear groove distance, abnormal patella lateral tilt, and coronal and torsional malalignment. The proper treatment is often debatable. Conservative treatment is suitable for acute dislocation but has a high failure rate for chronic instability, which usually necessitates surgical treatment. Today’s common surgical treatments focus on fixing anatomical defects, relieving symptoms of instability, and allowing patients to return to a suitable level of activity.Discussion and Conclusion: In this review, we summarize the relevant pathophysiology, categorization, clinical features, physical examination, imaging, and treatment options for patellofemoral instability.
ABSTRACT
Background@#This study aimed to 1) assess the effect of total hip arthroplasty (THA) on coronal limb alignment, namely, the hip–knee–ankle angle (HKA), 2) identify factors that determine changes in the HKA, and 3) determine whether alignment changes influence the knee joint space width. @*Methods@#We retrospectively evaluated 266 limbs of patients who underwent THA. Three types of prostheses with neck shaft angles (NSAs) of 132°, 135°, and 138° were used. Several radiographic parameters were measured in the preoperative and final radiographs (at least 5 years after THA). A paired t-test was used to confirm the effect of THA on HKA change.Multiple regression analysis was performed to identify radiographic parameters related to HKA changes following THA and changes in knee joint space width. Subgroup analyses were performed to reveal the effect of NSA change on the HKA change, and the proportion of total knee arthroplasty usage and changes in radiographic parameters between maintained joint space and narrowed joint space groups were compared. @*Results@#The preoperative mean HKA was 1.4° varus and increased to 2.7° varus after THA.This change was related to changes in the NSA, lateral distal femoral angle, and femoral bowing angle. In particular, in the group with a decrease in NSA of > 5°, the preoperative mean HKA was largely changed from 1.4° varus to 4.6° varus after THA. The prostheses with NSA of 132° and 135° also led to greater varus HKA changes than those with an NSA of 138°. Narrowing of the medial knee joint space was related to changes in the varus direction of the HKA, decrease in NSA, increase in femoral offset. @*Conclusion@#A large reduction in NSA can lead to considerable varus limb alignment after THA, which can have adverse effects on the medial compartment of the ipsilateral knee.
ABSTRACT
Background@#The purpose of this study was to analyze the epidemiology of T-score discordance between the spine and femur in the South Korean population and compare the prevalence of T-score discordance between the Korean osteoporosis population and atypical femoral fracture (AFF) patients. @*Methods@#A total of 12,422 subjects from the Korea National Health and Nutrition Examination Survey were reviewed retrospectively. T-score discordance was defined as a difference of ≥ 1 standard deviation between the lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD). The prevalence of T-score discordance (low LS [LS BMD FN BMD], and total [low LS + low FN]) was investigated in the osteoporosis and non-osteoporosis groups and stratified by sex and age. Tscore discordance of 63 patients with AFFs diagnosed at a single institution was compared with that of the Korean osteoporosis population using propensity score matching. @*Results@#T-score discordance was prevalent in the Korean osteoporosis population (44.8%), and low LS discordance (37.5%) was more frequently seen than low FN discordance (7.2%) (p < 0.001). The prevalence of total and low LS discordance was significantly higher in AFF patients than in the Korean osteoporosis population (total discordance: 69.8% and 42.5%, respectively; low LS discordance: 63.5% and 31.7%, respectively; p < 0.001). @*Conclusions@#T-score discordance was highly prevalent in the Korean osteoporosis population, and low LS discordance was more common than low FN discordance. Nevertheless, the prevalence of low LS discordance was significantly higher in AFF patients than in the Korean osteoporosis population.
ABSTRACT
Angular deformity of extremities in children and adolescents with residual growth is not a rare condition in orthopaedics. Asymmetrical physeal suppression or guided growth method, one of the surgical techniques for correction of angular deformity, is a method of inducing plastic deformation by application of constant external force to a growing bone. Internal fixation devices used for asymmetrical physeal suppression include staples, transphyseal screws, and tension band plates, most representatively the 8-plate. Temporary hemiepiphysiodesis using staples is reported to show a success rate of 60% to 80%. Epiphysiodesis using transphyseal screws has several advantages over staples or 8-plates; smaller skin incision, shorter operation time, no postoperative splint or cast, faster return to daily life. Advantages of 8-plates over staples or transphyseal plates include a longer moment arm, which enables better correction of angular deformity and less suppression of the growth of the nearby normal growth plate. Asymmetrical physeal suppression is a simple and effective surgical method in correcting angular deformity of extremities of children and adolescents. Each of three internal fixation devices discussed in the current article has strengths and weaknesses and superiority in terms of angular correction power and complication rate, however further study is needed. Therefore, the most appropriate device should be selected according to the condition of each patient.