Unicompartmental knee arthroplasty, an enigma, and the ten enigmas of medial UKA.

Unicompartmental knee arthroplasty (UKA) is a bone- and ligament-sparing alternative to total knee arthroplasty in the patients with end-stage single-compartment degeneration of the knee. Despite being a successful procedure, the multiple advantages of UKA do not correlate with its usage, most likely due to the concerns regarding prosthesis survivability, patient selection, ideal bearing design, and judicious use of advanced technology among many others. Therefore, the purpose of this study is to review and summarize the debated literature and discuss the controversies as "Ten Enigmas of UKA."

What is the evidence for clinical use of advanced technology in unicompartmental knee arthroplasty?

BACKGROUND: With an aim of improving prosthesis survivorship of unicompartmental knee arthroplasty (UKA), use of computer-assisted technologies (CATs) such as robotics, has been on the rise to reduce intraoperative errors in surgical technique. In light of recent influx of CATs in the UKA, a review of these innovations will help providers to understand their clinical utility. METHOD: A systematic literature search was performed following Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. RESULTS: Among 19 studies comparing robot-assisted UKA with conventional UKA, only 32% were randomized control trials, 47% reported minimum mean follow-up of 2 years, and 21% evaluated prosthesis survival. Similar results were obtained for navigation-assisted UKA and UKA performed with patient-specific instrumentation. CONCLUSION: While CATs seem to reduce the surgical errors in UKA, the evidence on the efficacy of any of the studied CATs to improve survivorship remains limited and there are issues related to cost-effectiveness, learning curve, and increase in operating time.

A review of plain radiographic methods for measuring femoral version after total hip arthroplasty and validation of modified Budin's method in Indian population.

BACKGROUND: Multiple plain radiographic methods; cross table radiographic method, modified Budin method, projected neck-shaft angle method, and trans lateral decubitus view method using Ogata-Goldsand formula, have been described in literature for measurement of femoral stem version (FSV) after total hip arthroplasty (THA). PURPOSE: To review these multiple radiographic methods and also determine validity and accuracy of modified Budin method in Indian population. PATIENTS AND METHODS: A literature search for different methods described for FSV measurement was performed and these methods were reviewed. In addition, for validation of modified Budin method in Indian population, data was collected for 36 THAs prospectively. A posteroanterior radiograph with patient sitting in 90° hip flexion and 30° abduction was taken 3 weeks and 6 weeks after surgery for calculating the FSV using modified Budin method. At 3 weeks, a CT scan was also done for version measurement. Intra and interobserver reliability, and reproducibility of radiographic FSV measurement, and the correlation between CT scan and radiographic FSV measurement were statistically calculated. RESULTS: All the reviewed studies demonstrated that their method is comparable to CT method for FSV measurement, except FSV measured on cross table radiographic view. However, there were only one or at most two studies of every method described except for modified Budin technique. The mean FSV in our prospective case series using 'modified Budin' method was 11.6° which was comparable to the mean of CT scan version measurement (12.3°). The mean difference was 0.7° which was not statistically significant (p value > 0.05). In addition, there was high intra-class correlation coefficient in radiographic FSV for both intra- and inter-observer reliability. CONCLUSION: Multiple methods have been described and validated in literature, however, the 'modified Budin' view have proved multiple times to have excellent reliability and validity for easy measurement of FSV.

Is mini-open intramedullary nailing an effective intervention for adult femoral diaphyseal fractures in odd hours? A prospective case-control functional outcome and radiation safety study.

BACKGROUND: Closed intramedullary (IM) nailing among various modalities is one of the commonest sought out procedure in current practice for management of femoral-diaphyseal fractures (FDF) following trauma. However, it has some limitations like prolonged procedural duration, high radiation exposure and a steep learning curve. Therefore, with limited resources in odd hours and at a high patient turnover center where closed reduction can be a challenge, we adopted a modified mini-open technique which can overcome the limitations of closed reduction technique. PURPOSE: To compare the closed IM nailing and mini-open technique in FDF in terms of radiation exposure, surgical duration, radiological and functional outcome. PATIENTS AND METHODS: A total of 100 patients (118 femurs) with FDF (AO 32A1-B2) operated in odd-hours (20:00-06:00 hrs. GMT +5.30) with closed (Group I, n=62) or mini-open (Group II, n=56) IM nailing technique between September 2018 to December 2019 with a minimum follow up of 12 months were included in this study. The functional outcomes were measured using Thoresen scoring system and statistical analysis were performed using paired t-test and χ2 -test. RESULTS: The overall mean patient age was 33.5 years (18-74 years). The mean surgical duration, c-arm shoots for reduction and radiological union time were 71.5 minutes, 21 shoots and 16 weeks, respectively for group I and 47.5 minutes, 9.4 shoots and 18 weeks for group II. There was significant difference between the two groups in mean surgical duration (p<0.05) and c-arm shoots (p<0.05). However, there was no statistical significant difference between time for union, rate of union, functional results and incidence of superficial or deep infection between the two groups. CONCLUSION: In conclusion, mini-open technique is a safer alternative in patients with FDF at high-volume centers and in odd-hours when the available resources are limited.

Evidence-based surgical technique for medial unicompartmental knee arthroplasty.

Unicompartmental knee arthroplasty (UKA) is a successful treatment modality in selected patients having advanced, single-compartment osteoarthritis of the knee. The bone and ligament preservation leading to shorter recovery periods, better functional outcomes, lower perioperative complication rates, and easier revision, if needed, are proposed as some of the advantages of UKA over total knee arthroplasty (TKA). Despite several advantages, UKA is reported to have higher failure rates as compared to TKA. The prosthesis failure of UKA is directly correlated to intraoperative technique-related factors like malpositioning of components and the inability to replicate the target-limb alignment as per preoperative planning. An evidence-based surgical technique for UKA may help surgeons to avoid the intraoperative technique-related errors. The purpose of this paper is to describe a stepwise surgical technique for the fixed-bearing medial UKA.

Constraint integration for efficient multiview pose estimation with self-occlusions.

Automatic initialization and tracking of human pose is an important task in visual surveillance. We present a part-based approach that incorporates a variety of constraints in a unified framework. These constraints include the kinematic constraints between parts that are physically connected to each other, the occlusion of one part by another and the high correlation between the appearance of certain parts, such as the arms. The location probability distribution of each part is determined by evaluating appropriate likelihood measures. The graphical (non-tree) structure representing the interdependencies between parts is utilized to "connect" such part distributions via nonparametric belief propagation. Methods are also developed to perform this optimization efficiently in the large space of pose configurations.