Backside Wear in Modern Total Knee Designs

Although modularity affords various options to the orthopedic surgeon, these benefits come at a price. The unintended bearing surface between the back surface of the tibial insert and the metallic tray results in micromotion leading to polyethylene wear debris. The objective of this study was to examine the backside wear of tibial inserts from three modern total knee designs with very different locking mechanisms: Insall-Burstein II® (IB II®), Optetrak®, and Advance®. A random sample of 71 inserts were obtained from our institution’s retrieval collection and examined to assess the extent of wear, depth of wear, and wear damage modes. Patient records were also obtained to determine patient age, body mass index, length of implantation, and reason for revision. Modes of wear damage (abrasion, burnishing, scratching, delamination, third body debris, surface deformation, and pitting) were then scored in each zone from 0 to 3 (0 = 0%, 1 = 0–10%, 2 = 10–50%, and 3 = >50%). The depth of wear was subjectively identified as removal of manufacturing identification markings stamped onto the inferior surface of the polyethylene. Both Advance® and IB II® polyethylene inserts showed significantly higher scores for backside wear than the Optetrak® inserts. All IB II® and Advance® implants showed evidence of backside wear, whereas 17% (5 out of 30) of the retrieved Optetrak® implants had no observable wear. There were no significant differences when comparing the depth of wear score between designs. The locking mechanism greatly affects the propensity for wear and should be considered when choosing a knee implant system.Key words: polyethylene, wear, knee, backside, back surface, locking mechanism     

Osteochondral Fracture of the Fourth Metatarsal Head Treated by Open Reduction and Internal Fixation

Fracture of the metatarsal head is uncommon, and reports of isolated osteochondral fracture of the metatarsal head are rare. Because of the distal location of the fracture, it is difficult to achieve and maintain reduction, and potential complications include avascular necrosis and subchondral fatigue fracture. The authors present a case of an osteochondral fracture in a 40-year-old man, which was treated by open reduction and internal fixation with a single twist-off screw, with good results 12 months postoperatively.     

The Impact of Financial Conflict of Interest on Surgical Research: An Observational Study of Published Manuscripts

Background

Substantial discrepancies exist between industry-reported and self-reported conflicts of interest (COI). Although authors with relevant, self-reported financial COI are more likely to write studies favorable to industry sponsors, it is unknown whether undisclosed COI have the same effect. We hypothesized that surgeons who fail to disclose COI are more likely to publish findings that are favorable to industry than surgeons with no COI.

Methods

PubMed was searched for articles in multiple surgical specialties. Financial COI reported by surgeons and industry were compared. COI were considered to be relevant if they were associated with the product(s) mentioned by an article. Primary outcome was favorability, which was defined as an impression favorable to the product(s) discussed by an article and was determined by 3 independent, blinded clinicians for each article. Primary analysis compared incomplete self-disclosure to no COI. Ordered logistic multivariable regression modeling was used to assess factors associated with favorability.

Results

Overall, 337 articles were reviewed. There was a high rate of discordance in the reporting of COI (70.3%). When surgeons failed to disclose COI, their conclusions were significantly more likely to favor industry than surgeons without COI (RR 1.2, 95% CI 1.1–1.4, p < 0.001). On multivariable analysis, any COI (regardless of relevance, disclosure, or monetary amount) were significantly associated with favorability.

Conclusions

Any financial COI (disclosed or undisclosed, relevant or not relevant) significantly influence whether studies report findings favorable to industry. More attention must be paid to improving research design, maximizing transparency in medical research, and insisting that surgeons disclose all COI, regardless of perceived relevance.

     

Modified Technique of Mesh Hepatorrhaphy for Management of Juxtahepatic Venous Injury in a Case of Blunt Liver Trauma: A Case Report

The liver is the most frequently injured organ in cases of blunt abdominal trauma. Injuries to the caudate lobe are rarely isolated and usually associated with retrohepatic caval injury or hepatic vein injury. The management of the associated vascular injuries is usually difficult owing to the short courses of the hepatic veins and the difficulty in obtaining proximal and distal control of the suprarenal and suprahepatic inferior vena cava – hence the frequency of perihepatic packing in the management of caudate lobe and hepatic venous injuries. We present here a rare case of the failure of perihepatic packing to effectively control hemorrhage from blunt injury to the caudate lobe and retrohepatic vena cava. A case of blunt abdominal trauma with injury to the caudate lobe and retrohepatic venous injury was initially managed with perihepatic packing. The patient developed hemorrhage 48 h after pack removal, which was then successfully managed with mesh hepatorrhaphy of the caudate lobe.     

TOPICAL TRETINOIN IMPROVES THE APPEARANCE OF PHOTO DAMAGED SKIN

A multicentre clinical trial has been conducted to assess the efficacy and safety of tretinoin 0.05% cream (Retin-A®) in the treatment of photodamaged Australian skin. Subjects with cutaneous facial photodamage were randomised to treatment with tretinoin (62) or vehicle (63) cream. After an initial two week run-in, all subjects applied the cream to the face, neck and left forearm/hand, once nightly for 24 weeks. Changes in clinical signs of photodamage and parameters of cutaneous irritation were assessed by investigators using a 7 point scale, whilst changes in signs of photodamage were rated by subjects using a 5 point scale. Changes in skin biopsies and silicone skin surface replicas were also assessed. Significant improvements in skin wrinkles, mottled hyperpigmentation, laxity, lentigines and roughness of tretinoin treated subjects were noted by investigators. Subjects receiving tretinoin noted significant improvements in skin wrinkles, tightness, colour and pores. Improvement in overall severity of photodamage was significantly greater for tretinoin treated subjects and was progressive over the study period. Histological findings included a significant increase in mean epidermal thickness. Significant topographical changes were not detected in skin surface replica sets. Cutaneous irritation, the most common side effect, was usually mild and transient. We conclude that tretinoin 0.05% cream significantly improved the appearance of photodamaged skin.