General: Por qué hay tanta trampa en la investigación con células madre

Why so Much Fake, Unduplicable Stem Cell Research?

Arthur L. Caplan, PhD

Medscape Business of Medicine > Ethics: Today's Hot Topics

May 20, 2014

http://www.medscape.com/viewarticle/825279?nlid=57714_944&src=wnl_edit_medp_orth&uac=21013EJ&spon=8

Rodilla/Knee/Knie: Hay que evitar la PTR en verano

Seasonality of infection rates after total joint arthroplasty.

Kane P, Chen C, Post Z, Radcliff K, Orozco F, Ong A

Orthopedics February 2014 - Volume 37 · Issue 2: e182-e186

Abstract

The correlation between season (fall, winter, spring, and summer) and infection rate in surgical patients is well defined in many specialties. To the authors' knowledge, there are no data in the literature on this phenomenon in patients undergoing total joint arthroplasty. They hypothesized that there would be an increased infection rate in the summer months in patients undergoing elective total joint arthroplasty. They retrospectively reviewed consecutive patients undergoing elective total hip or knee arthroplasty at a single institution during 1 year by a single surgeon. Wound infections were defined as any patient requiring oral antibiotics for cellulitis, readmission for intravenous antibiotics, a return to the operating room for irrigation and debridement, or excisional arthroplasty and placement of a cement spacer within 90 days of the initial procedure. Seventeen of 750 patients developed an infection, for an overall incidence of 2.2%. There was a statistically significant difference in infection rate according to season: 3 (1.5%) infections occurred in winter, 1 (0.5%) in spring, 9 (4.7%) in summer, and 4 (2.4%) in fall. The incidence was highest during July (4.5%), August (5.4%), and September (4.3%). There was a statistically significant difference in infection rate between summer/fall (3.6%) vs winter/spring (1.0%). There is an increase in the incidence of infection during summer months for patients undergoing total joint arthroplasty. The authors recommend increased surveillance and more thorough preoperative sterilization procedures during these warmer months

Rodilla/Knee/Knie: Cemento el justo

Can Cementing Technique Reduce the Cost of a Primary Total Knee Arthroplasty?

Maheshwari A, Argawal M, Naziri Q, Pivec R, Mont MA, Rasquinha VJ

J Knee Surg 2014 Apr 21.

Abstract

Studies on cost containment of total knee arthroplasty (TKA) have generated substantial interest over the past decade. Although multiple studies have evaluated the various intraoperative methods to control cost, no prior study has evaluated the economic impact and the clinical outcome based on amount of bone cement needed for a primary TKA. At a minimum of 3 years follow-up, we observed no difference in implant survivorship or Knee Society scores, but did observe substantial cost savings when one versus two packets of bone cement were used in combination with a hand mixing technique. By eliminating several extra cement mixing products, we achieved an approximately $1,000 cost saving per case with no difference in clinical outcomes at midterm follow-up.

Rodilla/Knee/Knie: Cuidado al interpretar la RMN ante el fracaso de una ligamentoplastia

A Radiographic Assessment of Failed Anterior Cruciate Ligament Reconstruction: Can Magnetic Resonance Imaging Predict Graft Integrity?

Waltz RA, Solomon DJ, Provencher MT

Am J Sports Med 2014 May 12

Abstract

BACKGROUND: Magnetic resonance imaging (MRI) showing an "intact" anterior cruciate ligament (ACL) graft may not correlate well with examination findings. Reasons for an ACL graft dysfunction may be from malpositioned tunnels, deficiency of secondary stabilizers, repeat injuries, or a combination of factors. 

PURPOSE: To evaluate the concordance/discordance of an ACL graft assessment between an arthroscopic evaluation, physical examination, and MRI and secondarily to evaluate the contributing variables to discordance. 

STUDY DESIGN: Case series; Level of evidence, 4.

METHODS: A total of 50 ACL revisions in 48 patients were retrospectively reviewed. The ACL graft status was recorded separately based on Lachman and pivot-shift test data, arthroscopic findings from operative reports, and MRI evaluation and was categorized into 3 groups: intact, partial tear, or complete tear. Two independent evaluators reviewed all of the preoperative radiographs and MRI scans, and interrater and intrarater reliability were evaluated. Concordance and discordance between a physical examination, arthroscopic evaluation, and MRI evaluation of the ACL graft were calculated. Graft position and type, mechanical axis, collateral ligament injuries, chondral and meniscal injuries, and mechanism of injury were evaluated as possible contributing factors using univariate and multivariate analyses. Sensitivity and specificity of MRI to detect a torn ACL graft and meniscal and chondral injuries on arthroscopic evaluation were calculated. 

RESULTS: The interobserver and intraobserver reliability for the MRI evaluation of the ACL graft were moderate, with combined κ values of .41 and .49, respectively. The femoral tunnel position was vertical in 88% and anterior in 46%. On MRI, the ACL graft was read as intact in 24%; however, no graft was intact on arthroscopic evaluation or physical examination. The greatest discordance was between the physical examination and MRI, with a rate of 52%. An insidious-onset mechanism of injury was significantly associated with discordance between MRI and arthroscopic evaluation of the ACL (P = .0003) and specifically with an intact ACL graft on MRI (P = .0014). The sensitivity and specificity of MRI to detect an ACL graft tear were 60% and 87%, respectively. 

CONCLUSION: Caution should be used when evaluating a failed ACL graft with MRI, especially in the absence of an acute mechanism of injury, as it may be unreliable and inconsistent.

General: Ese tumor que te hace dudar tiene su camino

Non-neoplastic Soft Tissue Masses That Mimic Sarcoma

Matthew W. Colman, Santiago Lozano-Calderon, Kevin A. Raskin, Francis J. Hornicek, Mark Gebhardt

Orthopedic Clinics of North America

Volume 45, Issue 2 , Pages 257-269, April 2014

Abstract 

Non-neoplastic soft tissue masses may mimic soft tissue sarcoma in a wide variety of clinical settings. Systematic and thorough review of patient history, physical examination, imaging, laboratory results, and biopsy will allow the clinician to differentiate between the two in most cases. We describe several common non-neoplastic entities that may mimic soft tissue sarcoma in case presentation format along with the characteristics that help distinguish them.

 

General: Injertos frescos congelados para reconstrucciones en pacientes jóvenes

The Principles and Applications of Fresh Frozen Allografts to Bone and Joint Reconstruction

Luis A. Aponte-Tinao,  Lucas E. Ritacco, Jose I. Albergo, Miguel A. Ayerza, D. Luis Muscolo, German L. Farfalli, M

Orthopedic Clinics of North America

Volume 45, Issue 2 , Pages 257-269, April 2014

Abstract 

Fresh frozen allograft reconstruction has been used for a long time in massive bone loss in orthopedic surgery. Allografts have the advantage of being biologic reconstructions, which gives them durability. Despite a greater number of complications in the short term, after 5 years these stabilize with high rates of survival after 10 years. The rate of early complications and the need for careful management in the first years has led the orthopedic surgeon to the use of other options. However, the potential durability of this reconstruction makes this one of the best options for younger patients with high life expectancy.

 

Trauma: ¿Sería mejor dejar de poner prótesis parciales cementadas en las fracturas de cadera?

A comparison of the use of uncemented hydroxyapatite-coated bipolar and cemented femoral stems in the treatment of femoral neck fractures: a case-control study

Bell, K. R., Clement, N. D., Jenkins, P. J., Keating, J. F

Bone Joint J 2014;96-B:299–305.

We performed a case–control study to compare the rates of further surgery, revision and complications, operating time and survival in patients who were treated with either an uncemented hydroxyapatite-coated Corail bipolar femoral stem or a cemented Exeter stem for a displaced intracapsular fracture of the hip. The mean age of the patients in the uncemented group was 82.5 years (53 to 97) and in the cemented group was 82.7 years (51 to 99) We used propensity score matching, adjusting for age, gender and the presence or absence of dementia and comorbidities, to produce a matched cohort receiving an Exeter stem (n = 69) with which to compare the outcome of patients receiving a Corail stem (n = 69). The Corail had a significantly lower all-cause rate of further surgery (p = 0.016; odds ratio (OR) 0.18, 95% CI 0.04 to 0.84) and number of hips undergoing major further surgery (p = 0.029; OR 0.13, 95% CI 0.01 to 1.09). The mean operating time was significantly less for the Corail group than for the cemented Exeter group (59 min [12 to 136] vs 70 min [40 to 175], p = 0.001). The Corail group also had a lower risk of a peri-prosthetic fracture (p = 0.042; OR 0.19, 95% CI 0.01 to 1.42) . There was no difference in the mortality rate between the groups. There were significantly fewer complications in the uncemented group, suggesting that the use of this stem would result in a decreased rate of morbidity in these frail patients. Whether this relates to an improved functional outcome remains unknown.

General: Preferible la sangre fresca

Impaired Red Blood Cell Deformability after Transfusion of Stored Allogeneic Blood but Not Autologous Salvaged Blood in Cardiac Surgery Patients

Salaria, Osman N. Barodka, Viachaslau M. Hogue, Charles W. Berkowitz, Dan E. Ness, Paul M. Wasey, Jack O.  Frank, Steven M

BACKGROUND: 

Both cardiopulmonary bypass (CPB) and red blood cell (RBC) storage are associated with detrimental changes in RBC structure and function that may adversely affect tissue oxygen delivery. We tested the hypothesis that in cardiac surgery patients, RBC deformability and aggregation are minimally affected by CPB with autologous salvaged blood alone but are negatively affected by the addition of stored allogeneic blood.

METHODS: 

In this prospective cohort study, 32 patients undergoing cardiac surgery with CPB were divided into 3 groups by transfusion status: autologous salvaged RBCs alone (Auto; n = 12), autologous salvaged RBCs + minimal (<5 units) stored allogeneic RBCs (Auto+Allo min; n = 10), and autologous salvaged RBCs + moderate (>=5 units) stored allogeneic RBCs (Auto+Allo mod; n = 10). Ektacytometry was used to measure RBC elongation index (deformability) and critical shear stress (aggregation) before, during, and for 3 days after surgery.

RESULTS: In the Auto group, RBC elongation index did not change significantly from the preoperative baseline. In the Auto+Allo min group, mean elongation index decreased from 32.31 +/- 0.02 (baseline) to 30.47 +/- 0.02 (nadir on postoperative day 1) (P = 0.003, representing a 6% change). In the Auto+Allo mod group, mean elongation index decreased from 32.7 +/- 0.02 (baseline) to 28.14 +/- 0.01 (nadir on postoperative day 1) (P = 0.0001, representing a 14% change). Deformability then dose-dependently recovered toward baseline over the first 3 postoperative days. Changes in aggregation were unrelated to transfusion (no difference among groups). For the 3 groups combined, mean critical shear stress decreased from 359 +/- 174 mPa to 170 +/- 141 mPa (P = 0.01, representing a 54% change), with the nadir at the end of surgery and returned to baseline by postoperative day 1.

CONCLUSIONS: 

In cardiac surgery patients, transfusion with stored allogeneic RBCs, but not autologous salvaged RBCs, is associated with a decrease in RBC cell membrane deformability that is dose-dependent and may persist beyond 3 postoperative days. These findings suggest that autologous salvaged RBCs may be of higher quality than stored RBCs, since the latter are subject to the so-called storage lesions.

Hombro/Shoulder/Schulter: hay que acordarse del os acromiale

Os acromiale: a review and an introduction of a new surgical technique for management.

Johnston PS, Paxton ES, Gordon V, Kraeutler MJ, Abboud JA, Williams GR

Orthop. Clin. North Am. 2013 Oct; 44(4):635-44.

Abstract

Os acromiale is a common finding in shoulder surgery. We review the anatomy, prevalence, pathophysiology, and treatment options for this diagnosis. In addition, we report on a case series of 6 patients with a symptomatic meso os acromiale who were treated with a new technique involving arthroscopic acromioplasty in conjunction with the excision of the acromial nonunion site. We have demonstrated this novel treatment method to be a safe and effective technique in this case series. This arthroscopic partial resection of an os acromiale is considered to be an alternative option for treating a symptomatic meso os acromiale.

Hombro/Shoulder/Schulter: En la dehiscencia del manguito rotador, el tamaño sí importa

Factors Predicting Rotator Cuff Retears: An Analysis of 1000 Consecutive Rotator Cuff Repairs.

Le BT, Wu XL, Lam PH, Murrell GA

Am J Sports Med 2014 May; 42(5):1134-1142.

BACKGROUND

The rate of retears after rotator cuff repair varies from 11% to 94%. A retear is associated with poorer subjective and objective clinical outcomes than intact repair.

PURPOSE

This study was designed to determine which preoperative and/or intraoperative factors held the greatest association with retears after arthroscopic rotator cuff repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study retrospectively evaluated 1000 consecutive patients who had undergone a primary rotator cuff repair by a single surgeon using an arthroscopic inverted-mattress knotless technique and who had undergone an ultrasound evaluation 6 months after surgery to assess repair integrity. Exclusion criteria included previous rotator cuff repair on the same shoulder, incomplete repair, and repair using a synthetic polytetrafluoroethylene patch. All patients had completed the modified L'Insalata Questionnaire and underwent a clinical examination before surgery. Measurements of tear size, tear thickness, associated shoulder injury, tissue quality, and tendon mobility were recorded intraoperatively.

RESULTS

The overall retear rate at 6 months after surgery was 17%. Retears occurred in 27% of full-thickness tears and 5% of partial-thickness tears (P < .0001). The best independent predictors of retears were anteroposterior tear length (correlation coefficient r = 0.41, P < .0001), tear size area (r = 0.40, P < .0001), mediolateral tear length (r = 0.34, P < .0001), tear thickness (r = 0.29, P < .0001), age at surgery (r = 0.27, P < .0001), and operative time (r = 0.18, P < .0001). These factors produced a predictive model for retears: logit P = (0.039 × age at surgery in years) + (0.027 × tear thickness in %) + (1 × anteroposterior tear length in cm) + (0.76 × mediolateral tear length in cm) - (0.17 × tear size area in cm(2)) + (0.018 × operative time in minutes) -9.7. Logit P can be transformed into P, which is the chance of retears at 6 months after surgery.

CONCLUSION

A rotator cuff retear is a multifactorial process with no single preoperative or intraoperative factor being overwhelmingly predictive of it. Nevertheless, rotator cuff tear size (tear dimensions, tear size area, and tear thickness) showed stronger associations with retears at 6 months after surgery than did measures of tissue quality and concomitant shoulder injuries.

Hombro/Shoulder/Schulter: Puentear el manguito sin nudos con buenos resultados

Arthroscopic knotless-anchor rotator cuff repair: a clinical and radiological evaluation.

Hug K, Gerhardt C, Haneveld H, Scheibel M.

Knee Surg Sports Traumatol Arthrosc 2014 May 4.

The goal of this study was to evaluate the clinical and radiological results of the arthroscopic knotless-anchor Speed-Bridge technique, in particular the pattern and the rate of retears. The results were compared with a modified Suture-Bridge knot-tying technique (mDR). The hypothesis is that arthroscopic knotless-anchor Speed-Bridge rotator cuff repair is a sufficient technique to address supraspinatus tears and differs in pattern of retears when compared to mDR.

METHODS

This study includes twenty-two consecutive patients (8f/14m ø 63.3 ± 7.2 years) undergoing knotless-anchor Speed-Bridge repair. The subjective shoulder value (SSV), Constant score (CS) and Western Ontario Rotator Cuff (WORC) Score were used for clinical follow-up. MRI scans were conducted within 3 weeks post-operatively, after 1 and after 2 years for analysis of (a) tendon integrity (according to Sugaya), (b) muscle atrophy according to Thomazeau and (c) fatty infiltration. Results were compared with 20 patients operated in mDR (ø 61.2 ± 7.5 years).

RESULTS

The mean follow-up was 24.4 ± 4.7 months. The average SSV was 88.7 ± 14.9 %, the CS was 78.2 ± 13.2 points (contralateral side 78.5 ± 16.6) and the WORC Score averaged 87.1 ± 18.2 %. On magnetic resonance imaging, the integrity failure rate was 22.7 % (n = 5). The pattern of retear was a medial cuff failure in 2/5 cases (mDR 4/5, n.s.). Muscular atrophy or fatty degeneration did not increase between surgery and follow-up (n.s.). Compared with mDR (25 %) reconstruction, no significant differences were obtained regarding integrity failure rate and muscular atrophy (n.s.).

CONCLUSION

The modified knotless-anchor Speed-Bridge technique shows good to excellent clinical results as well as acceptable retear rates. This technique eliminates medial and lateral knot impingement. Concerning the potential reduction in the medial strangulation of the tendon, there is a need for further clinical research. 

LEVEL OF EVIDENCE: III

Cadera/Hip/Hüfte: Debilidad y dolor tras PTC, piensa en el nervio

Ipsilateral Inflammatory Neuropathy After Hip Surgery

Ruple S. Laughlin, P. James B. Dyck, James C. Watson, Robert J. Spinner, Kimberly K. Amrami, J. Sierra, Robert T. Trousdale, Nathan P. Staff

Mayo Clinic Proceedings

Volume 89, Issue 4, Pages 454–461, April 2014

Abstract

Objective

To identify whether new ipsilateral weakness after hip surgery may be due to an inflammatory as opposed to a mechanical process.

Patients and Methods

Seven patients (8 hip surgeries) seen between July 1, 2008, and June 30, 2011, developed unexplained ipsilateral leg weakness and pain within 1 month of hip surgery, mimicking mechanical etiologies. Cutaneous sensory nerve biopsy distant from the site of surgery was performed on all the patients. Patient medical records were reviewed for the clinical, electrophysiologic, radiologic, and pathologic features of the new neuropathy.

Results

Results of all the nerve biopsies were abnormal, showing axonal damage (7 patients), inflammation (7 patients), signs of ischemic injury (7 patients), and nerve microvasculitis (6 patients). Six patients were treated with intravenous methylprednisolone. At median follow-up of 6 months, 6 patients showed improvement in function and pain.

Conclusion

In this case series, we demonstrate that inflammatory neuropathy is an important etiologic consideration in some patients with ipsilateral weakness and pain after hip surgery. In these patients, the inflammatory mechanism was ischemic injury due to microvasculitis. Identification of these patients through clinical suspicion and subsequent nerve biopsy may lead to improved outcomes with prompt initiation of immunotherapy.

General: Otra razón para no fumar

Cigarette Smoking Increases Complications Following Fracture: A Systematic Review

John A. Scolaro, Mara L. Schenker, Sarah Yannascoli, Keith Baldwin, Samir Mehta, Jaimo Ahn

J Bone Joint Surg Am, 2014 Apr 16;96(8):674-681

Abstract

Background: 

Smoking has been suggested to increase the rate of perioperative complications including soft-tissue complications, to decrease the rate of fracture union, and to prolong healing time. The purpose of our study was to systematically evaluate and analyze the literature regarding the relationship between smoking and healing following operative treatment of long-bone fractures.

Methods: 

We searched the MEDLINE, Embase, and Cochrane databases by pairing the search terms “smoking,” “tobacco,” and “nicotine” with the terms “fracture,” “nonunion,” delayed union,” and “healing.” Articles and citations were evaluated for relevance. Inclusion and exclusion criteria were established to maintain data quality for analysis. Relevant information was independently extracted and compared to ensure agreement. The methodological quality of the studies was determined. A random-effects model was used. The adjusted odds ratios (ORs) and frequency-weighted means for the primary and secondary outcome measures were calculated.

Results: 

Our initial search identified 7110 articles. Of the 237 articles that underwent further evaluation of the abstract, nineteen (seven prospective and twelve retrospective cohort studies) were included. The adjusted OR of nonunion in the smoking group compared with the nonsmoking group was 2.32 (95% confidence interval [CI], 1.76 to 3.06; p < 0.001). An increased nonunion rate was observed in smokers with a tibial fracture (OR, 2.16; 95% CI, 1.55 to 3.01; p < 0.001) and those with an open fracture (OR, 1.95; 95% CI, 1.3 to 2.9; p < 0.001). For all fractures, the mean healing time was longer for smokers (30.2 weeks; 95% CI, 22.7 to 37.7 weeks) than for nonsmokers (24.1 weeks; 95% CI, 17.3 to 30.9 weeks) (p = 0.18). Trends toward more superficial and deep infections of postoperative or traumatic wounds in smokers were noted; however, the differences in superficial and deep infection rates were not significant (p = 0.13 and p = 0.33, respectively).

Conclusions: 

Smoking significantly increased the risk of nonunion of fractures overall, tibial fractures, and open fractures. Nonsignificant trends toward increased time to union in all fractures and toward increased postoperative rates of superficial and deep infections were noted in smokers compared with nonsmokers.

Level of Evidence: 

Prognostic Level III