Iatrogenic femoral neuropathy following pelvic surgery has been known since the late 1800s. But there is no clear incidence rate or association with certain types of retractor and the modifiable factors which can decrease the incidence.

Pathogenesis is attributed to the continuous pressure exerted by the various self-retaining retractors on the pelvic sidewall and the psoas muscle.

The femoral nerve is the largest branch of the lumbar plexus arising from the dorsal divisions of the ventral rami of the second, third and fourth lumbar nerves. It comes down through the psoas muscle approximately 4 cm above the inguinal ligament. It at all times remains in the operative field of the surgeon who operates in the abdomen and pelvis. There is a relatively poor blood supply to the femoral nerve as it crosses the pelvis and is therefore susceptible to ischemia.

The femoral nerve 1 - 4 cm distal to the inguinal ligament separates into anterior and posterior sections. The anterior division of the femoral nerve gives off anterior cutaneous and muscular branches. The anterior division supplies the Sartorius muscle and the 2 sensory branches the intermediate and medial cutaneous nerves of the thigh. The posterior division supplies the quadriceps femoris and articularis genus. The femoral nerve also innervates the hip and knee joints.

We wanted to execute a systematic review to count at the incidence of femoral neuropathy secondary to self-retaining Retractors and the factors tied in with it. This in return should help us in the design phase of the Retractors to decrease the incidence of this debilitating iatrogenic injury (Table 1).

Operational Definition of Population and Intervention:

The population included in the review were only those who were undergoing open or laparotomy pelvic and abdominal surgeries either using or in some (control group) cases not using retractors. Though mostly adults were taken into consideration, but in few cases experience and complaints of people from all age groups have been considered. Femoral neuropathy and other problems caused by the nerves were the areas of main focus, though some comments and review has also been performed involving the universal purpose of the Retractors and the benefits and ease of them. Obese patients have also been taken into consideration and the subsequent results due to the use of Retractors have been reviewed as well.

Mostly no intervention was thought about at the time when the procedure was performed, but post-operative interventions were noted in a few cases where special handling has been needed for the patients during the notice point.

Search Strategy:

We carried on a systematic inspection of articles found from Jan 1970 from Jan 2015. The databases used in the search were EMBASE, PubMed, BIOSIS, Engineering Village, Web of Science, Best practice, Science Direct, CRCnetBASE, Proquest, Wiley Online Library, and Comprehensive Biomaterial. The database searches were performed using the mentioned keywords. Variations on the words i.e. different endings, plural etc were used along with the appropriate logic operators (OR, AND, etc.) as required for individual databases.

Inclusion and Exclusion Criteria:

The papers were required to be peer reviewed, with English language and published between January 1970 and January 2015. The articles were to be focused on adults and must include data focused on retractor used in pelvic or abdominal surgeries. They were discussing the effectiveness of the retention provided or any injury that occurred to the patient due to the retractor. Laparoscopies and endoscopic surgeries were excluded from the review.

Organization of Evidence:

A quantitative study, critical review form was used by all reviewers when summarizing the important information on each article. This form has been developed by McMaster University, Canada [1] . The review form includes summaries of the study’s purpose, whether a literature review had been completed, the design of the study and any biases that could have been operating, details of the sample sizes and characteristics and ethics approvals. The measure and outcomes, interventions, results, including statistical significance, patient dropouts and clinical importance, conclusions and implications were featured in the form. The reviewers used this form to review the articles chosen to be included in the study. The articles were equally distributed among the reviewers. Where reviewers disagreed in the form, the article was reviewed by one of the other two reviewers. Along with the form, the articles were ranked according to “Sackett’s levels of evidence and grades of recommendation” as explained by American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) [2] .

Typically, reviews only included studies with levels of evidence between I and V. In this review, all levels of evidence were included due to the nature of what was researched. Many of the retractors in use have been used since the 1970s. Our searches have shown that randomized controlled trials or other higher level of evidence study types has been rare for Retractors. This is likely to be due to a lack of motivation or need when the retractors were first developed and over the long period for which they have been in use, the detractors will be seen as a useful and necessary tool, but one that would not benefit from expensive or in- depth studies. Most articles related to retractors have been retrospective analyses and have therefore been included.

The results of the searches are given in Figure 1―participant flow diagram.

Two papers were excluded from the study once the articles were read in full because, despite their abstracts, they were found to not match the review’s requirements. One article explained how to use a retractor with strong bias towards the retractor [3] . No survey or trial was acquitted and there was no clinical support of the retractor. There was therefore no evidence for the retractor’s effectiveness in retaining the wound or any patient effects.

The second paper was excluded as it discussed a novel surgical procedure of a “mini laparotomy” [4] . The only mention of retractors was related to their placement and replacement during the surgery, but no data, evidence or comment were made on the effectiveness of retention or any effect on the patient due to the retractor use.

This resulted in a total number of articles to be reviewed be ten. A summary of the articles can be found in Table 2.

Study Characteristics:

A total of at least 12,880 surgeries were used in the ten articles considered in this review. Three of these studies were random control trials [5] [6] [7] , two were retrospective and prospective analyses [8] [9] with the remaining five being retrospective analyses. Of these cases, two were chosen not to be included in the statistical summaries. One paper [10] only had two cases considered and the