Tibial nerve neuropathy following medial opening-wedge high tibial osteotomy-case report of a rare technical complication

A 63-year-old woman developed tibial nerve injury caused by an overlong K wire and 4.5-mm cortical lag screw through the first distal hole below the osteotomy during medial opening-wedge high tibial osteotomy (HTO), leading to a lack of sensation on the sole of the foot with no disturbances in motor functions. The temporary lag screw in the first distal hole below the osteotomy is often inserted by an excessive length in order to compress the potentially fractured opposite cortex. By doing so, posterior neurovascular structures including the tibial nerve and the popliteal vessels can be injured. To avoid this type of injury during medial opening-wedge HTO, proper knee position and appropriate Hohmann retractor position in combination with meticulous insertion of the K wire or screw under fluoroscopic control are essential. In addition, our study reinforces the fact that different presentations of injury to the tibial nerve should be carefully considered in the absence of common diagnostic features, including weakness of the toe flexors and posterior tibial muscle of the leg with intractable pain.

Proximal tibial anterior open-wedge oblique osteotomy: A novel technique to correct genu recurvatum

BACKGROUND

For successful acute correction of genu recurvatum, accurate correction of plateau angle, restoration of anatomical axis, rigid fixation, and preservation of patellar height are essential. However, a surgical treatment that satisfies all these conditions has not yet been established. The purpose of this study was to evaluate the novel technique of proximal tibial anterior open-wedge oblique osteotomy (PT-AOWOO) for the treatment of genu recurvatum.

METHODS

Five patients with genu recurvatum underwent PT-AOWOO from 2008 to 2013. The open-wedge center of rotation of angulation (CORA) was determined by the intersection of transverse bisector line and tibial posterior cortex to prevent secondary translational deformity. An osteotomy was performed from the distal margin of the tibial tuberosity to the planned CORA to maintain patellar height and provide sufficient space for fixation. The opening gap was calculated by the picture-archiving and communications system (PACS)-Photoshop method.

RESULTS

The mean angle of recurvatum was 17° (range, 14 to 25°) preoperatively and -0.4° (range, -5° to 5°) postoperatively. The mean angle of the tibial plateau was 79.8° (range, 67 to 85°) preoperatively and 98.4° (range, 95 to 105°) postoperatively. Tibial anatomical axis was restored and the patellar height was maintained in all patients. The overall results were excellent in three patients and good in two patients.

CONCLUSIONS

The PT-AOWOO and its unique osteotomy level corrected the tibial plateau angle accurately, restored the sagittal tibial axis without translation, maintained patellar height, and enabled rigid fixation. This technique showed satisfactory radiologic and clinical outcomes without any complications.

Comparison between two angular stable locking plates for medial opening-wedge high tibial osteotomy: Decisive wedge locking plate versus TomoFix™

BACKGROUND

An adequate stable fixation implant should be used for medial opening-wedge high tibial osteotomy (MOWHTO) to promote rapid bone healing without complications. This study compared the radiographic and clinical outcomes as well as plate-specific complications between two angular stable locking plates in patients following MOWHTO.

METHOD

This prospective study involved 97 patients (50 with DWL^®, group I; 47 with TomoFix™, group II) undergoing MOWHTO for primary medial compartment osteoarthritis between 2010 and 2013. Clinical and radiographic evaluations were performed by using the HSS and WOMAC scores, and calculating mechanical femorotibial angle (mFTA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and posterior tibial slope (PTS) on radiographs both preoperatively and after 3 years.

RESULTS

A statistically significant difference was observed for the MPTA at the last follow-up between the two groups (P = 0.033). Additionally, the last follow-up MPTA of group I was associated with the osteotomy technique (P = 0.004) and preoperative JLCA (P = 0.034) whereas the last follow-up MPTA of group II was associated with gender (P = 0.001) and BMI (P = 0.008). Furthermore, the results showed that group I had a higher rate of non-union (4%) compared to that in group II (0%).

CONCLUSION

Both locking plates are useful tools in the treatment of medial compartment knee osteoarthritis with varus deformity in young, active patients. However, under special consideration of the complication we found in present study, the TomoFix™ seems to be a better alternative in using the MOWHTO for highly demanding patients.

Minimally invasive navigation-assisted versus conventional total knee arthroplasty: a meta-analysis

PURPOSE

It is unclear whether the minimally invasive navigation-assisted (MINA) or conventional (CONv) approach for primary total knee arthroplasty (TKA) leads to better clinical and radiographic outcomes. This meta-analysis compared the clinical and radiographic outcomes of the MINA and CONv approaches after primary TKA. It was hypothesized that there was no difference in clinical and radiographic outcomes between the two surgical approaches for primary TKA.

METHODS

This meta-analysis reviewed all studies that compared surgical time, incision length, flexion range of motion (ROM), Knee Society Score ( KSS), coronal mechanical axis (CMA), and coronal femoral component angle (CFCA) with various measurement tools, from direct interview to plain radiography, between the MINA and CONv approaches.

RESULTS

Five studies met the inclusion/exclusion criteria for the meta-analysis. The findings of this study suggest that surgical time (95 % CI -18.51 to 39.09; n.s.), KSS (95 % CI -8.55 to 30.84; n.s.), CMA (95 % CI -1.01 to 0.54; n.s.), and CFCA (95 % CI -0.91 to 2.97; n.s.) were similar between the two surgical approaches, whereas incision length (95 % CI -5.18 to -3.69; P < 0.001) was significantly shorter in the MINA approach and flexion ROM (95 % CI 14.26-19.01; P < 0.001) was significantly greater in the MINA approach.

CONCLUSIONS

There were no significant differences in clinical and radiographic outcomes, including surgical time, KSS, CMA, and CFCA, in patients who underwent MINA and CONv approach for primary TKA, but the MINA approach resulted in a slightly shorter incision length and increased flexion ROM than the CONv approach. Therefore, if particular attention has to be paid to patient's selection with appropriate counselling and surgeon's experience, MINA approach can provide early clinical benefit when compared with CONv approach. Besides, orthopaedic surgeons need to master the MINA and CONv approaches because both approaches have similar clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Therapeutic study, Level II.

Development, Quantification, Method Validation, and Stability Study of a Novel Fucoxanthin-Fortified Milk

To extend the scope of application of fucoxanthin, a marine carotenoid, whole milk (WM) and skimmed milk (SM) were fortified with fucoxanthin isolated from the microalga Phaeodactylum tricornutum to a final 8 μg/mL milk solution concentration. Using these liquid systems, a fucoxanthin analysis method implementing extraction and HPLC-DAD was developed and validated by accuracy, precision, system suitability, and robustness tests. The current method demonstrated good linearity over the range of 0.125-100 μg/mL fucoxanthin with R(2) = 1.0000, and all validation data supported its adequacy for use in fucoxanthin analysis from milk solution. To investigate fucoxanthin stability during milk production and distribution, fucoxanthin content was examined during storage, pasteurization, and drying processes under various conditions. Fucoxanthin in milk solutions showed better stabilizing effect in 1 month of storage period. Degradation rate constant (k) on fucoxanthin during this storage period suggested that fucoxanthin stability might be negatively correlated with decrease of temperature and increase of protein content such as casein and whey protein in milk matrix. In a comparison between SM and WM, fucoxantin in SM always showed better stability than that in WM during storage and three kinds of drying processes. This effect was also deduced to relate with protein content. In the pasteurization step, >91% of fucoxanthin was retained after three pasteurization processes even though the above trend was not found. This study demonstrated for the first time that milk products can be used as a basic food matrix for fucoxanthin application and that protein content in milk is an important factor for fucoxanthin stability.

Alignment in knee flexion position during navigation-assisted total knee arthroplasty

PURPOSE

The aim of this study was to demonstrate the lower limb alignment in knee flexion position after navigation-assisted total knee arthroplasty using the gap technique and to identify the correlative factors.

METHODS

One hundred and twenty consecutive osteoarthritic knees (120 patients) were prospectively enrolled for intraoperative data collection. All TKA surgeries were performed using the navigation system (OrthoPilot™, version 4.0; B. Braun Aesculap, Tuttlingen, Germany). Before and after final prosthesis implantation, the lower limb navigation alignment in both knee extension (0°) and knee flexion (90°) position was recorded. The knee flexion alignment was divided into three groups: varus, neutral and valgus alignment. To determine the factors of the alignment in knee flexion position, preoperative demographics, radiologic and intraoperative data were obtained. Pearson's correlation (r) analysis was performed to find the correlation. The Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index were compared between groups.

RESULTS

Although all postoperative extension alignment was within neutral position (between -2° and +2°), postoperative knee flexion alignment was divided into three groups: varus (≤-3°), 24 cases (20 %); neutral (between -2° and +2°), 85 cases (70.8 %) and valgus (≥+3°) alignment, 11 cases (9.2 %). There were a good correlation of alignment in knee flexion position with the rotation of femoral component relative to posterior condylar axis (r = -0.502, p = 0.000) and weak correlations with posterior femoral cut thickness (lateral condyle) (r = 0.207, p = 0.026), medial flexion (90°) gap after femoral component rotation adjustment (r = 0.276, p = 0.003). Other variables did not show correlations. There were no statistical clinical differences between varus, neutral and valgus knee flexion alignment groups.

CONCLUSION

About 30 % of the cases showed malalignment of more than 3° in knee flexion position although with neutral alignment in extension position. The knee flexion alignment had a good correlation with the rotation of femoral component relative to posterior condylar axis. Neutral alignment in knee flexion position may be adjusted by femoral component rotation especially by the use of navigation system.

LEVEL OF EVIDENCE

IV.

A Novel Medial Soft Tissue Release Method for Varus Deformity during Total Knee Arthroplasty: Femoral Origin Release of the Medial Collateral Ligament

Introduction

Numerous methods of medial soft tissue release for severe varus deformity during total knee arthroplasty (TKA) have been reported. These include tibial stripping of the superficial medial collateral ligament (MCL), pie-crusting technique, and medial epicondylar osteotomy. However, there are inherent disadvantages in these techniques. Authors hereby present a novel quantitative method: femoral origin release of the medial collateral ligament (FORM).

Surgical Technique

For medial tightness remaining even after the release of the deep MCL and semimembranosus, the FORM is initiated with identification of the femoral insertion area of the MCL with the knee in flexion. Starting from the most posterior part of the femoral insertion, one third of the MCL femoral insertion is released from its attachment. If necessary, further sequential medial release is performed.

Materials and Methods

Seventeen knees that underwent the FORM were evaluated for radiological and clinical outcomes.

Results

Regardless of the extent of the FORM, no knees showed residual valgus instability at 24 weeks after surgery.

Conclusions

As the FORM is performed in a stepwise manner, fine adjustment during medial release might be beneficial to prevent inadvertent over-release of the medial structures of the knee.

Imageless Navigation Versus Conventional Open Wedge High Tibial Osteotomy: A Meta-Analysis of Comparative Studies

Purpose

To summarize and compare radiological and clinical outcomes of open wedge high tibial osteotomy (HTO) using imageless computer-assisted navigation with conventional HTO.

Methods

A literature search of online register databases was conducted. The risk ratio (RR) of radiological outliers and mean differences in clinical outcomes were compared between navigated and conventional HTOs. Radiological results were evaluated by subgroup analyses according to the study period (concurrent/consecutive) and the use of locking fixation device.

Results

Seven comparative studies with a total sample size of 406 knees were included in this review. Radiographically, the mechanical axis [MA] was within the acceptable range (0°–6°) in 83.7% of the navigation HTO group, showing significant difference from 62.1% of the conventional HTO group. Clinically, despite the forest plot demonstrating a general trend of favoring the navigation system, there were not sufficient studies to determine statistical significance in the meta-analysis. None of the subgroup analyses demonstrated significant differences in the RR of MA outliers.

Conclusions

The present meta-analysis indicates that the use of navigation in open wedge HTO improves the precision of mechanical alignment by decreasing the incidence of outliers; however, the clinical benefit is not conclusive. Additionally, none of the subgroup analyses demonstrated significant difference in the RR of MA outliers.

Subcutaneous versus intraarticular closed suction indwelling drainage after total knee arthroplasty: A randomised control trial

BACKGROUND

Total knee arthroplasty (TKA) is widely accepted treatment for moderate or severe osteoarthritis and rheumatoid arthritis. Significant blood loss can be seen during the early postoperative period where a blood transfusion may be necessary. Closed suction drainage is known to prevent the formation of hematomas in the operative field, decrease tension on incisions, diminish delayed wound healing and reduce the risk of infection. Subcutaneous indwelling closed suction drainage method has been known to be beneficial and an alternative to the intraarticular indwelling method. This prospective randomized study was to compare the visible, hidden, total blood loss and postoperative hemodynamic change of subcutaneous and intraarticular indwelling closed suction drainage method after TKA.

MATERIALS AND METHODS

One hundred and sixty patients with primary osteoarthritis who underwent unilateral TKA were enrolled; group A with subcutaneous (n = 78) and group B with intraarticular (n = 79) indwelling closed suction drainage method. Total blood loss, visible blood loss, internal blood loss, postoperative day 1, 5(th), 10(th) day hemoglobin, hematocrit levels were compared. Allogeneic blood transfusion rate and complications related to soft tissue hematoma formation were additionally compared.

RESULTS

Allogenic transfusion requirements between subcutaneous drainage group and intraarticular drainage groups (6.4% vs. 24.1%) were significantly different (P = 0.002). Although the minor complications such as the incidence of bullae formation and the ecchymosis were higher in the subcutaneous indwelling group, the functional outcome at postoperative 2 year did not demonstrate the difference from intraarticular drainage group.

CONCLUSION

Subcutaneous indwelling closed suction drainage method is a reasonable option after TKA for reduction of postoperative bleeding and transfusion rate.

Loose body as an obstacle for posterolateral arthroscopic portal formation in the knee joint

In this report, we present a case with difficult arthroscopic posterolateral portal formation due to loose body located in posterior compartment. These loose bodies are responsible for pain, decreased range of motion and cartilage damage in the knee joint. By making the posterior trans-septal portal prior, posterolateral portal could be made without difficulty completing the planned arthroscopic procedure.

Influence of Mixed Solvent on the Electrochemical Property of Hybrid Capacitor

The hybrid capacitors (2245 size, cylindrical type) were prepared by using activated carbon cathode and Li4Ti5O12 anode. In order to improve the cell operation at high temperature range, propylene carbonate (PC) was used in combination with acetonitrile (AN) with volume ratio of 7:3, 5:5, and 3:7, respectively. We investigated the electrochemical behavior of the hybrid capacitors that enabled cell operation with stability at high temperature. The organic electrolyte of hybrid capacitor containing PC and AN with a volume ratio 7:3 intended to exhibit highly reversible cycle performance with good capacity retention at 60 degrees C after 2200 cycles. From this study, it has been found that the very strong influence of the solvent nature on the characteristics of hybrid capacitor, and the difference in performance associated with the two solvents.

Current status of second-look arthroscopy after meniscal allograft transplantation: review of the literature

INTRODUCTION

Clinical assessments do not accurately reflect the status of meniscal transplants and cannot evaluate the graft condition itself and joint preservation effects of meniscal allograft transplantation correctly. The purpose of this review was to assess the need and to ascertain the indication and the role of second-look arthroscopy for objective evaluation after MAT.

MATERIALS AND METHODS

We performed a literature search to identify all published clinical studies on MAT with the following medical subject heading (MeSH) terms: "meniscus," "meniscal transplant," "transplantation and allograft," "meniscal and transplant." Include in the review are studies with at least 6 months clinical, radiological, and/or histological follow-up in human subjects. Evaluation method of MAT was reviewed with an aim to describe the frequency of second-look arthroscopy, its feasibility, patient compliance, purposes, and results.

RESULTS

We identified 15 clinical studies that satisfied our inclusion and exclusion criteria. Only two studies always performed second-look arthroscopies. Most of the second-look arthroscopy was conducted mainly for the objective evaluation of meniscal allograft transplantation but, in several studies, arthroscopy was performed to treatment of other knee problem.

CONCLUSIONS

Although second-look arthroscopy has inevitably ethical issues, especially for asymptomatic and well-functioning knees, in this review, it could be a more dependable method available to detect meniscal healing if performed for certain indications such as a symptomatic patient with a magnetic resonance image indicating abnormalities.

The use of contralateral knee magnetic resonance imaging to predict meniscal size during meniscal allograft transplantation

PURPOSE

The purpose of this study was to determine the size of each meniscus and compare it with the contralateral limb using conventional knee magnetic resonance imaging (MRI) taken from previously uninjured, healthy, young volunteers.

METHODS

The knee joints of 60 healthy volunteers (aged 21 to 43 years, 30 men and 30 women) were enrolled in this study. Standard 3.0-T MRI in a controlled setting was used. By use of the mid-coronal images, the height and width of each medial and lateral meniscus were measured. By use of the mid-sagittal images, the height and width of the anterior and posterior horns of each meniscus was measured. The whole length spanning from the most anterior margin to the most posterior margin of each meniscus was also measured. Mean, standard deviation, and 95% confidence interval values were determined for each measurement.

RESULTS

There were 3 incomplete discoid lateral menisci (10%) in men and 2 incomplete discoid menisci (6.7%) in women. The study group with non-discoid knees comprised 27 men and 28 women. The power of this study ranged from 0.57 to 0.66. All values showed good reliability (intraclass correlation coefficient range, 0.887 to 0.974). There were no significant differences between right and left menisci (all P > .05). There were significant differences between genders. All parameters showed significant differences (P < .05) except the medial meniscus width (P = .221).

CONCLUSIONS

In this small subset of patients, there were no differences between right and left meniscal measurements according to MRI. Therefore, when one is performing meniscal allograft transplantation, contralateral knee MRI may be useful to determine the required size. Identifying both the overall width and length of each meniscus is important when preparing an allograft.

CLINICAL RELEVANCE

Contralateral knee MRI may be used for more accurate meniscal size measurement in patients undergoing meniscal allograft transplantation.

Navigated Acetabular Cup Fixation for Acetabular Deformity or Revision Total Hip Arthroplasty

Purpose

To evaluate the usefulness of navigated acetabular cup fixation for total hip arthroplasty in patients with acetabular deformity or revision total hip arthroplasty.

Materials and Methods

This study enrolled 28 patients with at least 12 months' follow-up. The safe zone of the acetabular cup was defined as 40°±10°in inclination and 15°±10°in anteversion. The authors used the navigation and radiographic data to determine whether the acetabular cup was located within the safe zone or not. To evaluate the clinical outcomes, preoperative and last follow-up Harris hip scores were checked, and the occurrence of complications was evaluated.

Results

According to the navigation data, the mean inclination and anteversion were 38.5°±4.7°(range, 32°-50°) and 16.6°±4.0°(range, 8°-23°), respectively. According to the radiographic data the mean inclination and anteversion were 40.5°±4.6°(range, 32°-50°) and 19.4°±4.2°(range, 8°-25°), respectively. In both cases, all values were within the safe zone. Harris hip score was improved in all patients from preoperative 52.3±14.4 points (range, 29-87 points) to 88.0±9.0 points (range, 65-99 points) at the last follow-up. There was no dislocation or loosening of both cases.

Conclusion

Navigated acetabular cup fixation is a useful technique for total hip arthroplasty in patients with acetabular deformity or revision total hip arthroplasty because it prevents the malposition and related complications.

Thrombospondin-2 secreted by human umbilical cord blood-derived mesenchymal stem cells promotes chondrogenic differentiation

Increasing evidence indicates that the secretome of mesenchymal stem cells (MSCs) has therapeutic potential for the treatment of various diseases, including cartilage disorders. However, the paracrine mechanisms underlying cartilage repair by MSCs are poorly understood. Here, we show that human umbilical cord blood-derived MSCs (hUCB-MSCs) promoted differentiation of chondroprogenitor cells by paracrine action. This paracrine effect of hUCB-MSCs on chondroprogenitor cells was increased by treatment with synovial fluid (SF) obtained from osteoarthritis (OA) patients but was decreased by SF of fracture patients, compared to that of an untreated group. To identify paracrine factors underlying the chondrogenic effect of hUCB-MSCs, the secretomes of hUCB-MSCs stimulated by OA SF or fracture SF were analyzed using a biotin label-based antibody array. Among the proteins increased in response to these two kinds of SF, thrombospondin-2 (TSP-2) was specifically increased in only OA SF-treated hUCB-MSCs. In order to determine the role of TSP-2, exogenous TSP-2 was added to a micromass culture of chondroprogenitor cells. We found that TSP-2 had chondrogenic effects on chondroprogenitor cells via PKCα, ERK, p38/MAPK, and Notch signaling pathways. Knockdown of TSP-2 expression on hUCB-MSCs using small interfering RNA abolished the chondrogenic effects of hUCB-MSCs on chondroprogenitor cells. In parallel with in vitro analysis, the cartilage regenerating effect of hUCB-MSCs and TSP-2 was also demonstrated using a rabbit full-thickness osteochondral-defect model. Our findings suggested that hUCB-MSCs can stimulate the differentiation of locally presented endogenous chondroprogenitor cells by TSP-2, which finally leads to cartilage regeneration.

Bilateral condyle fracture of tibial insert in mobile bearing total knee arthroplasty

We report a case of polyethylene insert breakage in a 45-year-old man after 3.5 years of cruciate retaining type mobile bearing total knee arthroplasty (TKA). Interstingly, both condyles of the polyethylene insert have fractured. The visual assessment done by stereoscopic microscope in the investigation report suggested that the fracture propagation was a result of cyclic loading and that the fracture was from the articular surface as a result of tibio-femoral and anteroposterior shear loading. The initial flexion-extension gap mismatch and/or specific Asian habits like kneeling or deep knee bending could have been the possible factors for over-stress for the insert causing this complication. After replacement of the broken insert and modification for daily activity preventing deep knee flexion, the patient obtained complete relief of previous symptoms. It remains unclear whether insert breakage was secondary to polyethylene insufficient design or to the polyethylene material fracture propagation.

Predictive value of painful popping for a posterior root tear of the medial meniscus in middle-aged to older Asian patients

PURPOSE

The purpose of this study was to determine the accuracy, sensitivity, specificity, and predictive values of a single event of painful popping in the presence of a posterior root tear of the medial meniscus in middle-aged to older Asian patients.

METHODS

We conducted a retrospective review of medical records of 936 patients who underwent arthroscopic surgeries for an isolated medial meniscus tear between January 2000 and December 2010. There were 332 men and 604 women with a mean age of 41 years (range, 25 to 66 years). The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of a painful popping sensation for a posterior root tear of the medial meniscus were calculated.

RESULTS

Arthroscopy confirmed the presence of posterior root tears of the medial menisci in 237 of 936 patients (25.3%). A single event of a painful popping sensation was present in 86 of these 936 patients (9.1%). Of these 86 patients with a painful popping sensation, 83 (96.5%) were categorized as having an isolated posterior root tear of the medial meniscus. The positive predictive value of a painful popping sensation in identifying a posterior root tear of the medial meniscus was 96.5%, the negative predictive value was 81.8%, the sensitivity was 35.0%, the specificity was 99.5%, and the diagnostic accuracy was 77.9%.

CONCLUSIONS

A single event of painful popping can be a highly predictive clinical sign of a posterior root tear of the medial meniscus in the middle-aged to older Asian population. However, it has low sensitivity for the detection of a posterior root tear of the medial meniscus.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Total knee arthroplasty in a pseudoachondroplastic dwarfism patient with bilateral patellar dislocation

Late presentation of congenital patellar dislocation with advanced osteoarthritis is rare. This article presents a case of a 59-year-old man with underlying pseudoachondroplastic dwarfism. Advanced osteoarthritis due to bilateral neglected congenital patellar dislocation was treated with total knee arthroplasty without patella relocation surgery. Two years later, the patient had an improvement in Knee Society scores, painless function, and stability.

The management of the popliteus hiatus during lateral meniscal transplantation

Popliteofascicular injury had been proposed as a possible cause of unstable lateral meniscus. Meniscal repair at popliteal hiatus area during lateral meniscal allograft transplantation (MAT) had not been described in literature previously. In this report, a case of unstable lateral meniscus after MAT has been described. Arthroscopic repair for the unstable meniscus at popliteal hiatus resolved the mechanical symptom.

Comparison of the predictive power of the LODS and APACHE II scoring systems in a neurological intensive care unit

OBJECTIVE

A prospective study to compare the power of the Logistic Organ Dysfunction System (LODS) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring systems to predict survival, in patients admitted to the neurological intensive care unit (NICU).

METHODS

Clinical data from 521 consecutive NICU patients were collected during the first 24 h of admission and were used to compare the predictive power of both scoring systems.

RESULTS

The observed mortality rate was 10.0% compared with predicted mortality rates of 7.2% and 4.8% according to LODS and APACHE II, respectively. Both scoring systems had excellent discrimination but LODS had superior calibration.

CONCLUSION

The LODS scoring system was more stable than the APACHE II scoring system in the NICU setting.

Second-look arthroscopic assessment of arthroscopic single-bundle posterior cruciate ligament reconstruction: comparison of mixed graft versus achilles tendon allograft

BACKGROUND

Although controversy continues over the choice of graft tissue, including autografts, allografts, and synthetic ligaments, for posterior cruciate ligament (PCL) reconstruction, the use of a mixed graft consisting of a hamstring (semitendinosus and gracilis) autograft plus tibialis anterior allograft tendon has not been studied in detail.

HYPOTHESIS

Outcomes of PCL reconstructions performed with a mixed graft would be superior to those using solely an Achilles tendon allograft in terms of functional knee scores, posterior stability, and the graft appearance.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Fifty-eight patients who underwent isolated single-bundle PCL reconstruction using an arthroscopic trans-septal portal with remnant preservation technique were evaluated. They were divided into group A (mixed tendon; n = 30) and group B (Achilles tendon; n = 28). Knee function was evaluated using the Lysholm knee score, Tegner activity score, and the International Knee Documentation Committee (IKDC) grading scale. Anteroposterior stability was measured using the Telos stress view. Twenty patients (66.7%) from group A and 21 patients (75.0%) from group B underwent hardware removal and a second-look arthroscopic examination.

RESULTS

The Lysholm knee scores in groups A and B increased from a respective average of 43 and 50 preoperatively to 90 and 88 at follow-up. The IKDC grade and Tegner activity scores were also significantly improved in both groups. Stability was improved in both groups, with an average posterior laxity of 3.0 mm (group A) and 3.3 mm (group B) at follow-up (P > .05). However, there were 4 intraoperative complications in group B: 2 bone fractures and 2 graft pullouts during precyclic tensioning. Second-look arthroscopy revealed a partial tear in 8 cases (40%) from group A and 15 cases (71.4%) from group B (P = .03). All of the partial tears were located in the femoral aperture area. Complete synovial coverage was demonstrated in 10 patients (50%) from group A and 5 patients (23.8%) from group B (P = .04). However, clinical outcomes and stability were not affected by the arthroscopic graft appearance.

CONCLUSION

Satisfactory results were obtained for groups A and B in patients who underwent reconstruction for isolated PCL injury. However, 4 intraoperative complications (14.3%) were encountered with use of the Achilles tendon allograft (group B), with a relative higher rate of partial tear and less synovialization in the femoral aperture area.

Loss of PTEN induces microtentacles through PI3K-independent activation of cofilin

Loss of PTEN tumor suppressor enhances metastatic risk in breast cancer, although the underlying mechanisms are poorly defined. We report that homozygous deletion of PTEN in mammary epithelial cells induces tubulin-based microtentacles (McTNs) that facilitate cell reattachment and homotypic aggregation. Treatment with contractility-modulating drugs showed that McTNs in PTEN(-/-) cells are suppressible by controlling the actin cytoskeleton. Because outward microtubule extension is counteracted by actin cortical contraction, increased activity of actin-severing proteins could release constraints on McTN formation in PTEN(-/-) cells. One such actin-severing protein, cofilin, is activated in detached PTEN(-/-) cells that could weaken the actin cortex to promote McTNs. Expression of wild-type cofilin, an activated mutant (S3A), and an inactive mutant (S3E) demonstrated that altering cofilin phosphorylation directly affects McTNs formation. Chemical inhibition of PI3K did not reduce McTNs or inactivate cofilin in PTEN(-/-) cells. Additionally, knock-in expression of the two most common PI3K-activating mutations observed in human cancer patients did not increase McTNs or activate cofilin. PTEN loss and PI3K activation also caused differential activation of the cofilin regulators, LIM-kinase1 (LIMK) and Slingshot-1L (SSH). Furthermore, McTNs were suppressed and cofilin was inactivated by restoration of PTEN in the PTEN(-/-) cells, indicating that both the elevation of McTNs and the activation of cofilin are specific results arising from PTEN loss. These data identify a novel mechanism by which PTEN loss could remodel the cortical actin network to facilitate McTNs that promote tumor cell reattachment and aggregation. Using isogenic MCF-10A PTEN(-/-) and PIK3CA mutants, we have further demonstrated that there are clear differences in activation of cofilin, LIMK and SSH between PTEN loss and PI3K activation, providing a new evidence that these mutations yield distinct cytoskeletal phenotypes, which could have an impact on tumor biology.