Quadriceps Tendon With Bone Autograft Has Better Stability and Magnetic Resonance Imaging Maturation Than Hamstring Tendon Autograft After Anterior Cruciate Ligament Reconstruction in Patients With Knee Hyperextension.

PURPOSE: To compare the clinical outcomes of anterior cruciate ligament (ACL) reconstruction between methods using quadriceps tendon with bone (QTB) and hamstring tendon (HT) in patients with hyperextension of the knee. METHODS: The medical records of patients with knee hyperextension greater than 8° who underwent arthroscopic ACL reconstruction between October 2010 and October 2020 with follow-up for at least 2 years (median, 3 years; interquartile range [IQR], 2.0-4.6 years) were retrospectively reviewed. Side-to-side difference in anterior translation, pivot-shift test grade, Lysholm score, and graft intensity using the Howell grade on magnetic resonance imaging at final follow-up were compared between the QTB and HT groups. RESULTS: The HT and QTB groups consisted of 42 patients and 21 patients, respectively. The overall mean age was 21.5 years (range, 14-48 years), and the median Tegner Activity Scale score was 6 (range, 3-9). Postoperatively, the median side-to-side difference in anterior translation was 1.75 mm (IQR, 1-3 mm) in the HT group and 1.0 mm (IQR, 0-1.75 mm) in the QTB group (P = .01). Pivot-shift testing showed grade 0 in 74.7%, grade 1 in 18.7%, and grade 2 in 6.6% of patients in the HT group and grade 0 in 85.7% and grade 1 in 14.3% of those in the QTB group (P = .03). The median postoperative Lysholm score was 99 in both groups. Graft signal intensity showed a significant between-group difference: grade I in 52%, grade II in 36%, and grade III in 12% of patients in the HT group versus grade I in 85.7%, grade II in 9.5%, and grade III in 4.8% of those in the QTB group (P = .03). CONCLUSIONS: In patients who underwent ACL reconstruction for hyperextension of the knee, QTB yielded better clinical outcomes than HT with respect to anterior stability, rotational stability, and graft signal intensity on median 2-year follow-up magnetic resonance imaging. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Ganglion Cyst Resection of the Anterior Cruciate Ligament using the Posterior Trans-Septal Approach: A Report of 2 Cases.

CASE: We present 2 patients each with an intra-articular ganglion cyst arising at the femoral attachment of the anterior cruciate ligament that was successfully resected using the posterior trans-septal portal approach. At the final follow-up, the patients had no recurrence of symptoms and no recurrence of the ganglion cyst on magnetic resonance imaging. CONCLUSION: Surgeons should consider the trans-septal portal approach when they cannot visually confirm the intra-articular ganglion cyst by the arthroscopic anterior approach. The trans-septal portal approach enabled complete visualization of the ganglion cyst located in the posterior compartment of the knee.

UniCon: A unified star-operation to efficiently find connected components on a cluster of commodity hardware.

With a cluster of commodity hardware, how can we efficiently find all connected components of an enormous graph containing hundreds of billions of nodes and edges? The problem of finding connected components has been used in various applications such as pattern recognition, reachability indexing, graph compression, graph partitioning, and random walk. Several studies have been proposed to efficiently find connected components in various environments. Most existing single-machine and distributed-memory algorithms are limited in scalability as they have to load all data generated during the process into the main memory; they require expensive machines with vast memory capacities to handle large graphs. Several MapReduce algorithms try to handle large graphs by exploiting distributed storage but fail due to data explosion problems, which is a phenomenon that significantly increases the size of data as the computation proceeds. The latest MapReduce algorithms resolve the problem by proposing two distinguishing star-operations and executing them alternately, while the star-operations still cause massive network traffic as a star-operation is a distributed operation that connects each node to its smallest neighbor. In this paper, we unite the two star-operations into a single operation, namely UniStar, and propose UniCon, a new distributed algorithm for finding connected components in enormous graphs using UniStar. The partition-aware processing of UniStar effectively resolves the data explosion problems. We further optimize UniStar by filtering dispensable edges and exploiting a hybrid data structure. Experimental results with a cluster of 10 cheap machines each of which is equipped with Intel Xeon E3-1220 CPU (4-cores at 3.10GHz), 16GB RAM, and 2 SSDs of 1TB show that UniCon is up to 13 times faster than competitors on real-world graphs. UniCon succeeds in processing a tremendous graph with 129 billion edges, which is up to 4096 times larger than graphs competitors can process.

Patients with a quadriceps tendon shorter than 60 mm require a patellar bone plug autograft in anterior cruciate ligament reconstruction.

PURPOSE: To assess the length and thickness of the quadriceps tendon (QT) and anterior cruciate ligament (ACL) to predict the required QT length for individual ACL reconstruction. METHODS: Thirty patients (9 females, 21 males; mean age 24.5 years; mean height 169.3 cm) who underwent ACL reconstruction using the QT with a bone plug autograft were enrolled. The length and thickness of the QT on preoperative magnetic resonance imaging (MRI) were compared with those measured under direct visualization. The ACL length was measured on preoperative MRI and three-dimensional computed tomography after ACL reconstruction. The QT length on MRI was compared with the required graft length, and the factors related to an adequate QT length were assessed. RESULTS: The mean QT length on MRI was 60.8 ± 1.3 mm and was significantly positively correlated with the QT length under direct visualization (P < 0.01). On MRI, the mean ACL length was 30.8 ± 1.2 mm and the mean QT thickness was 6.3 ± 0.2 mm. Although the mean QT was 0.1 mm longer than the mean required graft length, the QT on MRI was shorter than the required graft length in 37% of patients (11/30). Adequate QT length was related to a QT length of more than 60 mm, but not to age, sex, height, or ACL length. CONCLUSION: Although preoperative MRI predicted the required QT length for ACL reconstruction, 37% of patients lacked an adequate QT length, and a QT shorter than 60 mm required the addition of patellar bone. LEVEL OF EVIDENCE: III.

Development of Swallowing Function in Infants with Oral Feeding Difficulties.

BACKGROUND: Discharge of preterm infants is often delayed because of their oral feeding difficulties. Independent oral feeding is the last obstacle to pass after managing acute and chronic morbidities. We conducted this study to determine the prevalence, characteristics, and risk factors of swallowing dysfunction and suggest proper interventions to reduce aspiration and chronic lung injury. METHODS: Infants admitted to the neonatal intensive care unit (January 2016 to December 2018) who were performed modified barium swallow study due to oral feeding difficulties were enrolled. Modified barium swallow study was done ≥ postmenstrual age 37 weeks to limit radiation exposure. Clinical data were collected retrospectively. Swallowing dysfunction was defined as inadequate epiglottic closure, laryngeal penetration, or tracheal aspiration according to result of the modified barium swallow study. RESULTS: Among a total of 54 infants enrolled, nine (16.7%) were term infants, 13 (24.1%) were late preterm infants (gestational age, 34-36 weeks), and 32 (59.3%) were early preterm infants (gestational age < 34 weeks). Gestational age and birth weight were smaller in infants with swallowing dysfunction. Total duration of mechanical ventilation and duration of invasive ventilation were longer in infants with swallowing dysfunction. The risk of swallowing dysfunction increased by 11.2 times for infants with gestational age < 29 weeks compared to infants with gestational age ≥ 29 weeks. Swallowing dysfunction was improved in most infants after they became matured. They showed different time and rate of maturation with the help of rehabilitation through swallow therapy and dietary modification with thickened formula. CONCLUSION: Preterm infants with gestational age < 29 weeks or with longer ventilation duration are at a higher risk of aspiration. Rehabilitation of swallow therapy and dietary modification with thickened formula can be helpful interventions to prevent aspiration and chronic lung injury and reassure parents until independent oral feeding is possible.

The Modified Socket Shield Technique.

OBJECTIVE: In the anterior regions, the resorption of the buccal bone after tooth extraction leads to a contraction of the overlying soft tissues, resulting in an esthetic problem, particularly with immediate implant placement. In the socket shield technique, the buccal root section of the tooth is maintained, to preserve the buccal bone for immediate implant placement. The aim of this prospective study was to investigate the survival, stability, and complication rates of implants placed using a "modified" socket shield technique. METHODS: Over a 2-year period, all patients referred to a dental clinic for treatment with oral implants were considered for inclusion in this study. Inclusion criteria were healthy adult patients who presented nonrestorable single teeth with intact buccal periodontal tissues in the anterior regions of both jaws. Exclusion criteria were teeth with present/past periodontal disease, vertical root fractures on the buccal aspect, horizontal fractures below bone level, and external/internal resorptions. The buccal portion of the root was retained to prevent the resorption of the buccal bone; the shield was 1.5 mm thick with the most coronal portion at the bone crest level. All patients then underwent immediate implants. In the patient with a gap between the implant and shield, no graft material was placed. All implants were immediately restored with single crowns and followed for 1 year. The main outcomes were implant survival, stability, and complications. RESULTS: Thirty patients (15 males, 15 females; mean age was 48.2 ±â€Š15.0 years) were enrolled in the study and installed with 40 immediate implants. After 1 year, all implants were functioning, for a survival rate of 100%; excellent implant stability was reported (mean implant stability quotient at placement: 72.9 ±â€Š5.9; after 1 year: 74.6 ±â€Š2.7). No biologic complications were reported, and the incidence of prosthetic complications was low (2.5%). CONCLUSIONS: The "modified" socket shield technique seems to be a successful procedure when combined with immediate implant placement, because the root fragment does not interfere with osseointegration and may be beneficial for the esthetics, protecting the buccal bone from resorption.

One-stage revision ACL reconstruction after primary ACL double bundle reconstruction: is bone-patella tendon-bone autograft reliable?

PURPOSE: The purpose of this study is to assess the results of revision anterior cruciate ligament (ACL) reconstruction after the failure of primary ACL double bundle reconstruction (ACL-DBR). METHODS: Twenty-two knees in 22 patients (group R) that underwent ACL revision surgery using bone-patellar tendon-bone (BTB) autograft after the failure of primary ACL-DBR were included in this study. Intraoperative findings and postoperative knee laxity and clinical outcomes in group R were assessed. Forty-four knees in 44 patients that were age- and gender- matched with group R and underwent primary ACL reconstruction using BTB autograft were used as a control group (group P). RESULTS: The incidence of medial meniscus and cartilage injury in group R was significantly higher than those in group P (p < 0.05). At final follow-up, median Lysholm score was 90.5 (64-100) in group R and 94 (59-100) in group P, respectively. Fourteen patients (63.6%) in group R and 31 patients (70.5%) in group P were able to return to previously-played sports, respectively. There were no significant differences in KT-1000 outcomes (2.0 mm in group R and 1.4 mm in group P) or pivot shift test between the two groups. The rate of subsequent ACL injury was similar in both groups. CONCLUSIONS: Revision ACL reconstruction using BTB autograft after failed primary ACL-DBR provided almost compatible postoperative clinical outcomes and knee stability with primary ACL reconstruction using BTB autograft, while the incidence of medial meniscus and cartilage injury at revision surgery was higher. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Alveolar Ridge Reconstruction with Titanium Meshes and Simultaneous Implant Placement: A Retrospective, Multicenter Clinical Study.

Objective. To evaluate horizontal bone gain and implant survival and complication rates in patients treated with titanium meshes placed simultaneously with dental implants and fixed over them. Methods. Twenty-five patients treated with 40 implants and simultaneous guided bone regeneration with titanium meshes (i-Gen®, MegaGen, Gyeongbuk, Republic of Korea) were selected for inclusion in the present retrospective multicenter study. Primary outcomes were horizontal bone gain and implant survival; secondary outcomes were biological and prosthetic complications. Results. After the removal of titanium meshes, the CBCT evaluation revealed a mean horizontal bone gain of 3.67 mm (±0.89). The most frequent complications were mild postoperative edema (12/25 patients: 48%) and discomfort after surgery (10/25 patients: 40%); these complications were resolved within one week. Titanium mesh exposure occurred in 6 patients (6/25 : 24%): one of these suffered partial loss of the graft and another experienced complete graft loss and implant failure. An implant survival rate of 97.5% (implant-based) and a peri-implant marginal bone loss of 0.43 mm (±0.15) were recorded after 1 year. Conclusions. The horizontal ridge reconstruction with titanium meshes placed simultaneously with dental implants achieved predictable satisfactory results. Prospective randomized controlled trials on a larger sample of patients are required to validate these positive outcomes.

Immediate Loading of Tapered Implants Placed in Postextraction Sockets and Healed Sites.

OBJECTIVE: The aim of the present study was to compare the survival, stability, and complications of immediately loaded implants placed in postextraction sockets and healed sites. METHODS: Over a 2-year period, all patients presenting with partial or complete edentulism of the maxilla and/or mandible (healed site group, at least 4 months of healing after tooth extraction) or in need of replacement of nonrecoverable failing teeth (postextraction group) were considered for inclusion in this study. Tapered implants featuring a nanostructured calcium-incorporated surface were placed and loaded immediately. The prosthetic restorations comprised single crowns, fixed partial dentures, and fixed full arches. Primary outcomes were implant survival, stability, and complications. Implant stability was assessed at placement and at each follow-up evaluation (1 week, 3 months, and 1 year after placement): implants with an insertion torque (IT) <45 N·cm and/or with an implant stability quotient (ISQ) <70 were considered failed for immediate loading. A statistical analysis was performed. RESULTS: Thirty implants were placed in postextraction sockets of 17 patients, and 32 implants were placed in healed sites of 22 patients. There were no statistically significant differences in ISQ values between the 2 groups, at each assessment. In total, 60 implants (96.8%) had an IT ≥45 and an ISQ ≥70 at placement and at each follow-up control: all these implants were successfully loaded. Only 2 implants (1 in a postextraction socket and 1 in a healed site, 3.2%) could not achieve an IT ≥45 N·cm and/or an ISQ ≥70 at placement or over time: accordingly, these were considered failed for stability, as they could not be subjected to immediate loading. One of these 2 implants, in a healed site of a posterior maxilla, had to be removed, yielding an overall 1-year implant survival rate of 98.4%. No complications were reported. No significant differences were reported between the 2 groups with respect to implant failures and complications. CONCLUSION: Immediately loaded implants placed in postextraction sockets and healed sites had similar high survival and stability, with no reported complications. Further long-term studies on larger samples of patients are needed to confirm these results.