Thigh and Knee Liposuction

Updated: Mar 30, 2023
Author: John A Grossman, MD; Chief Editor: Zubin J Panthaki, MD, CM, FACS, FRCSC 



Liposuction, or suction-assisted lipoplasty (SAL), currently is the most commonly performed cosmetic surgery in the United States, possibly the most common in the world. Liposuction is very popular because of its tangible, immediate results; however, viewing this surgical procedure as simply glorified cosmetology without risk, as something that can be performed by anyone with a suction machine and a willing patient, would be a dangerous mistake.

Using data from the American Board of Plastic Surgery, a study by Stein et al indicated that thigh and knee SAL procedures have become less frequent since the early 21st century. According to the investigators, between 2005 and 2014, the thighs accounted for 36% of body areas undergoing SAL, compared with 23% between 2015 and 2021. For the knees, these figures were 8% and 5%, respectively. The abdomen, in contrast, accounted for 64% of body areas treated with SAL during the earlier timespan, and 69% during the later one.[1]

History of the Procedure

Liposuction, or SAL, first burst on the scene in a presentation by the French surgeon Dr Yves-Gerard Illouz, in 1982. His presentation was quickly followed by his professional publication in 1983, in which he described a 5-year, 3000-case experience with the technique of suction-assisted lipolysis (his term).[2] His method was quite straightforward and consisted of the following:

  1. Instill a hypotonic saline solution into areas of fat (theoretically to "rupture" the adipocytes).

  2. Insert blunt-tipped, hollow metal cannulas (of 5-, 8-, and 10-mm internal diameters with a lateral side opening) into these fatty deposits.

  3. Attach the cannulas via hose or tube to a high-power suction machine.

  4. Move these cannulas in and out of the fat in a fan-shaped pattern.

This process aspirated the fat and allowed the operator to sculpt the fatty areas into a more pleasing shape. Almost immediately upon the release of Illouz's studies and the overwhelming interest they generated, surgeons worldwide and medical historians recalled earlier descriptions of concepts of surgical fat extraction and sculpting, dating back to the work of Dujarier in France during the 1920s. Unfortunately, his work resulted in disaster.

More contemporary examples in the literature included the work of Josef Schrudde in Cologne, Germany who described fat curettage and suction of the hips, thighs, knees, and ankles in the early 1960s and presented his work at a meeting in 1972. Also in the early 1970s, Kesselring of Switzerland and Fischer of Italy published similar suction fat curettage reports.

These techniques failed to elicit significant interest among other plastic surgeons either in Europe or the United States, as their results were inconsistent and complications common and significant. Other plastic surgeons took note only when Illouz developed his technique of suction-assisted lipolysis using blunt cannulas and high-vacuum suction and demonstrated both reproducible good results and low morbidity. Moreno-Moraga et al concluded that laser-assisted lipolysis in knee remodeling is a safe and reproducible technique that reduces the amount of adipose deposits while providing concurrent skin contraction.[3]

Modern plastic surgery history, while taking into account the various early methods of shaping, sculpting, and removing fat, considers Illouz the father of modern liposuction. What Courtiss in 1984 deemed controversial, citing that "...some authors tout its advantages; [while] others warn of potential dangers..." is now the most common aesthetic surgical procedure performed in the United States.[4]  According to The Aesthetic Society, 491,098 liposuction procedures were performed in the United States in 2021.[5]

Since many more nonplastic surgeons also now perform liposuction, the likely total number becomes even more astounding. Yet to reconfirm the old adage that the more things change, the more they stay the same, a 2000 article and survey cites an unacceptably high mortality rate of 1 in 5000 for liposuction surgery.[6] Prior to liposuction, surgically shaping the thigh amounted to a surgical procedure in which a large lateral elliptical wedge of skin and fat was removed from the upper outer thigh (saddlebag region) and the tissues brought together to improve the contour somewhat at the cost of a rather unpleasant scar. Other shaping procedures involved similar sorts of wide excisions from the upper inner aspect of the thigh. Shaping the knee was not realistically within the realm of possibility; therefore, liposuction in the thigh and knee areas created the opportunity to perform true sculpting of flesh in an effective and aesthetically pleasing fashion.

Evolution of technical aspects

In the years since Illouz's presentation, as liposuction has become a mainstay of the plastic surgeon's armamentarium, the technique has evolved considerably. When first described, the technique by its very nature had certain limitations. For example, candidates for liposuction were restricted to generally younger individuals with good skin elasticity to avoid postoperative laxity. The volume that could be extracted was constrained by the considerable blood loss, and the large diameter of the cannulas restricted use of the technique in certain anatomic areas.

Blood loss and lidocaine replacement

The issue of blood loss cannot be minimized, and the limitations it placed on liposuction led to an evolution of subcutaneous fluid instillation. It began with the movement from the dry technique (where no fluid was injected into the fatty tissues and blood loss was significant) to the wet technique, in which an adrenalin solution is injected into the tissues to be liposuctioned. This allowed surgeons to remove greater fat volumes with reduced (though still not negligible) blood loss.

Subsequently, larger and larger volumes of dilute lidocaine and adrenalin were injected, with improved results. This culminated in Jeffrey Klein's description of the tumescent technique (his term), in which dilute buffered lidocaine and adrenalin are injected into the tissues to be suctioned to the point of turgidity.[7] The composition of the fluid delivers a total dose of lidocaine that far exceeds the recommended dose (35 mg/kg vs 4-6 mg/kg).

Numerous studies have examined and explained this phenomenon. Both the solution and the method and volume of injection significantly minimize blood loss, allowing for safe larger volume liposuction. The process by which this occurs has been described as "...internal exsanguinations of the tissue [in which there is a] ... three-dimensional effect of pressurized dilute lidocaine and epinephrine solution effectively [controlling] local vascular responses, providing for an almost bloodless aspirate and enhanced postoperative pain control." Since then, the instillation of a fluid medium, a dilute buffered lidocaine and adrenalin mixture, has become the standard of care. Particular fluid composition and volume vary somewhat among surgeons from the "tumescent technique" of Klein to the "superwet" technique of Fodor and others (see image below).[7, 8]

Liposuction, thigh and knee. Infusing tumescent fl Liposuction, thigh and knee. Infusing tumescent fluid.

Advances in liposuction techniques with the development of wetting solutions has led to some confusion and resultant disasters, as discussed by Fodor, in part because of a lack of consistent definitions and understanding of physiologic effects of large-volume instillation of fluids and local anesthetic drugs.[8] Thus, several definitions must be clarified below.

  • Dry technique: Currently, liposuction without instillation of any fluid in the area being treated is rarely, if ever, used.

  • Wet technique: This technique is still being used. It involves instillation of isotonic dilute epinephrine solution (with or without lidocaine) in volumes of 200-300 mL per area being liposuctioned.

  • Superwet technique: This is commonly used. It involves instillation of isotonic (usually Ringer lactate-based), extremely dilute lidocaine (0.04-0.05%) and epinephrine (1:1,000,000-1:2,000,000) solution in volumes of 1-1.5 mL/mL of expected/projected fat aspirate per location. The solution is similar in composition to tumescent infusate; however, the solution is not the main source of anesthesia.

  • Tumescent technique: This technique is commonly used. It involves instillation of solution similar or the same as superwet solution but in volumes of either 3-4 mL per expected/projected fat aspirate per location or whatever volume is needed to bring tissues to a palpably turgid, hard state.

    • In the classic tumescent technique, instilled solution is the main source of anesthesia.

    • Many liposurgeons, use the tumescent definition of fluid instillation with some other form of anesthesia (sedation, spinal, epidural, general).

    • Often, surgeons use the term tumescent to refer to any significant fluid instillation at the site of liposuction without a clear understanding of the volumes being injected.

Large-volume fluid and local anesthetic agent instillation and extractions commonly seen in current liposuction procedures have created significant problems in fluid and drug management with cardiopulmonary and other complications. This situation requires both liposurgeons and anesthesiologists to be present and fully cognizant of the complexities of fluid and drug management.

All of the infusate fluids for liposuction, whether tumescent or superwet, contain a dose of lidocaine that should concern the uninitiated anesthesiologist. The manufacturers' recommended maximum dose of lidocaine is 7 mg/kg. Yet the tumescent and other wetting solutions may contain 35 mg/kg or even more. "When dilute lidocaine mixed with epinephrine is infiltrated into the subcutaneous tissues in the manner [utilized in standard tumescent liposuction], lidocaine is avidly bound to the tissues and only slowly released into the circulation...Toxic plasma levels are not reached."

Various other physiologic processes are occurring, yet it has been demonstrated repeatedly that serum lidocaine levels remain beneath the toxic level. Additionally, peak lidocaine levels usually do not occur until about 12-14 hours after injection. This fact has been used as an indication to monitor liposuction patients for the first night following surgery.

As mentioned earlier, blood loss has been reduced to a minimal level. Various studies have been performed in which most agree with the general range quoted by Pitman that estimates average blood loss after tumescent SAL at 1-10% of total aspirate volume.


The size, shape, and design of cannulas have evolved. Currently, surgeons use much finer cannulas of inner diameters seldom greater than 4 mm. These usually have a design that includes multiple holes either on one side or around the entire tip (see image below). Shapes, sizes, and positions of the holes allow for faster yet more exacting shaping and sculpting of fatty tissues.

Liposuction, thigh and knee. Mercedes tip design l Liposuction, thigh and knee. Mercedes tip design liposuction cannulas.

Ultrasonic assisted liposuction and external ultrasonic assisted liposuction

Finally, evolution of the technique has included the introduction of ultrasonic assisted liposuction (UAL) and external ultrasonic assisted liposuction (EUAL). The latter technique remains controversial and of questionable value. In UAL, ultrasonic energy is applied to specially designed liposuction cannulas, causing cavitation of fat deposits in its direct path and surrounding its tip and leading to more bloodless, easier, and more efficient removal of fat. The technique is normally used in concert with standard SAL. UAL is performed first to break up and liquefy large areas of fat, and SAL thereafter removes liquefied fat as well as the remaining areas that require sculpting and removal. Among the developments in ultrasonic-assisted liposuction is the so-called VASER technology, which uses a low-power ultrasound that produces a more selective fat cavitation with low risk of injury or burns to surrounding tissue.

Other options in liposuction include power-assisted liposuction handpieces that reduce the surgeon's work effort while increasing the movement of the cannula in and out of the tissues.


Other changes that have occurred with time and greater experience and understanding of the surgery include (1) size, number, and location of incisions; (2) drainage and dressings; (3) postoperative compression; and (4) patient selection criteria. Incision size is reduced to barely several millimeters yet the number of incisions has increased, as surgeons have felt liberated to use as many small access incisions as necessary to effectively perform the surgery. While most surgeons still close these incisions, they usually can be closed only with a subcuticular suture. Many surgeons do not close the incisions at all.

Some surgeons have elected to leave access incisions open postoperatively to promote drainage of tumescent fluid and blood and have reported no adverse effects on wound healing and scarring. Other surgeons have instituted the use of fine drains for several days postprocedure to evacuate fluid collections, which, theoretically, reduces postoperative soft-tissue edema and, ultimately, reduces the formation of scar tissue.

Postoperative taping and dressings have become less important, although compressive garments are still considered important to obtain a good result. Initially, age was believed to be a major criterion in selection because of the assumption of poor skin elasticity, yet current practice judges patients on an individual basis, regardless of age. Surgery itself generates a surprising degree of skin contraction, allowing for further liberalization of skin elasticity criteria.


Lipodystrophy describes the abnormal or excess fat deposits that are indications for liposuction surgery. It may not, strictly speaking, be the correct term to use since an abnormality of fat metabolism or biochemistry is not being described. The author is simply using it to describe an excessive and unattractive fat collection that is the result of heredity, lifestyle, and nutritional habits. While localized obesity may be a more appropriate term, custom has led to the use of lipodystrophy for the fat collections patients present with.

Lipodystrophy of the thighs and/or knees occurs in the presence of either abnormal localized collections of fat of several areas of the thighs (outer thigh or saddlebag, upper inner thigh at thigh-groin junction, entire inner thigh, anterior thigh, posterior thigh) and/or knees (medial, medial anterior, lateral anterior, posterior) or excess fat of the circumferential thigh.



Frequency of occurrence of this problem is probably impossible to estimate, especially since the criteria are both objective and subjective. It is not just a question of estimating the number of obese individuals in the United States, North America, or the world, nor is it a problem limited to the obese. Many people of normal weight range have isolated or localized collections of fat on the thighs and knees. As obesity rates in the United States increase, the incidence of bariatric surgery and postbariatric plastic surgery grows. Liposuction is an intimate part of these surgeries. Thus, the extent of potential patients with this problem is massive and continues to grow exponentially.


Without extensively exploring the subject of fat metabolism, one can accurately state that at some time in late childhood, the total number of lipocytes (fat cells) of each individual becomes fixed. New fat cells are not made over the course of one's lifespan. Both the general distribution of these cells and their proclivity to enlarge with weight gain and reduce with loss is genetically predetermined. The pattern is uniquely individual.

Interpreted in another way, each of us is born with a unique figure, body habitus, and metabolism, as unique as our fingerprints. Perfect physique and perfect distribution of fat and muscle are uncommon. Especially among women, disproportionate fat distribution of the thighs and/or knees is a common occurrence: a result of heredity, lifestyle, and hormones.


"Attractive legs are characterized by a gradual tapering from strong thighs to delicate ankles. Although slight fullness at the knees is ...[normal], most women regard their knees as unattractive and wish to eliminate any bulge..." Patients presenting for possible liposuction of the thighs and/or knees usually can be separated into several general categories.

  1. Patients with well-localized excess fat deposits, good skin tone and elasticity, and no significant generalized obesity

  2. Patients with more generalized excess fat of the thighs and knees and good-to-partially substandard skin elasticity

  3. Patients with extremely poor skin tone and laxity and either localized or generalized fatty deposits. These patients are more appropriate candidates for some type of skin excision lift procedure and usually have worse laxity following liposuction. Women are far more likely to present with these problems than men.

Medial and lateral deposits of both small and large volumes are the most common indication for thigh liposuction. Anterior thigh excess is not usually an isolated problem; it commonly occurs in the setting of circumferential excess requiring circumferential thigh liposuction.

Considerations for liposuction

Consider skin quality, tone, elasticity, and volume for liposuction. While some skin contraction can occur, SAL also can produce a worse case of laxity. Where skin excision thigh lifting is the appropriate procedure, liposuction cannot adequately replace it. As mentioned, there are several types of excess fullness at the knee, and the most common is medial fullness. This results from a combination of underlying anatomy and a localized area of subcutaneous fat. A fatty fullness above the patella is basically a result of the quadriceps and skin laxity and is best left untouched. Other less common collections include medial and lateral infrapatellar pockets. These are well corrected with liposuction.


As with any cosmetic surgery, indications are somewhat different from necessary and corrective surgery. The basic indication is the desire to have surgical correction or improvement of a particular esthetic problem. Beyond this, indications include the following:

  • The presence of a correctable problem as described above: lipodystrophy of the thighs and/or knees in the setting of acceptable skin elasticity

  • Body weight at or moderately above the ideal

  • Satisfactory physical and mental health

  • Reasonable and realistic expectations of outcome

These factors are essentially issues of patient selection, which is particularly important in the world of aesthetic plastic surgery. In liposuction, remember that it is not a weight reduction alternative. It is most suited to sculpting localized deposits of fat that do not easily resolve with dietary control and exercise and remodeling the body contour.

While large-volume, body-shaping liposuction has been discussed recently in the literature, it is beyond the scope of standard liposuction. As fat distribution is a combination of heredity and lifestyle, most people have collections of fat and resultant shapes that persist despite diet and regular exercise. As for all elective cosmetic procedures, indications for surgery are a combination of a patient's perceived need and desire for the surgery and the physician's subjective and objective evaluation. In theory, anyone is a potential candidate if they possess localized fatty deposits amenable to liposuction.

Liposuction is a technique best used to sculpt and shape individual areas.[9] When not working with localized areas, it begins to become a generalized weight reduction technique instead of serving its basic purpose. In thighs and knees, liposuction produces its most visibly outstanding results in treating prominent saddlebags, bulging upper inner thighs, and inner knees. While circumferential thigh liposuction is performed, consider in the evaluation the subsequent relationship of the newly shaped thigh with the lower leg to avoid possible disproportion.

Pinch test

Some liposurgeons have attempted to turn the physical examination and process of patient selection into a more scientific process by performing a pinch test. In the pinch test, the area being evaluated is pinched between thumb and forefinger. The minimum measurement acceptable for liposuction is felt to be 3 cm for the outer, anterior, and posterior thigh and knee and 2 cm for the upper inner thigh.

Lifting the skin

Lifting the skin distinguishes a fat bulge, particularly of the outer thigh, and skin laxity that is best treated with a thigh lift.[10] Have the patient tense the muscles to distinguish between muscle and fat. Less useful in the thighs and knees than the abdomen, it distinguishes between external fat and muscle. This is particularly useful for the abdomen.

Skin elasticity

Overlying skin should have sufficient elasticity so that it will contract. In the early days of liposuction, being older than 40 years was a contraindication for liposuction because of the assumption of poor skin elasticity. Time and experience have shown that this absolute is not reasonable, and each patient must be judged individually. Nevertheless, when examination reveals poor skin elasticity, striae, and extreme laxity preliposuction, the surgeon must reconsider unless the location is amenable to skin resection. In some locations (abdomen, upper inner thigh, arm), excess skin-removing surgeries are possible. These must be discussed thoroughly with patients, and they must be made aware of additional scarring and associated risks.

Body weight

Another indication is body weight at or moderately above ideal weight. Moderately above ideal weight means approximately 20-40 lb above ideal weight. While even generally overweight individuals may have localized areas of fat that are distinctly disproportionate to the surrounding areas and thus appropriate sites for liposuction, there is also the potential that the entire body needs reduction. Such a generalized body liposuction is beyond the scope of the original intent of this surgery.

Generalized obesity

Recent studies have demonstrated the possibility of pushing the envelope and extending the purpose of liposuction beyond mere sculpting to large-volume liposuction to improve overall body shape and weight reduction. Previously, it has been suggested that such large-volume liposuction is associated with many complications, including fatalities; however, these recent reports claim extensive experience with large-volume liposuction in several hundred patients without significant complications and without mortality. Nevertheless, do not consider large-volume liposuction routine and do not select patients for routine liposuction who are poor candidates.

Satisfactory physical and mental health

See the list below:

  • Physical health: Every surgical procedure is associated with risks and potential complications. In treating a life-threatening or potentially debilitating disorder, the risk-to-benefit ratio is much clearer. In a purely cosmetic vanity surgery, even moderate risk is not acceptable. When acute or chronic diseases are present that elevate the level of risk, the prudent surgeon should not agree to perform elective surgery. This does not mean that otherwise well patients who meet the other criteria but have well-controlled chronic diseases may not be candidates for liposuction. However, it does mean to examine the equation more rigorously. In the same category are issues such as cigarette smoking, excessive alcohol intake, and use of diet control drugs.

  • Mental health

    • Cosmetic plastic surgeons see more than their fair share of patients with both unrealistic expectations and mental disorders. Such problems as eating disorders, other body image problems, and schizophrenia may be frank contraindications to liposuction surgery. There may be merit to the suggestions by some plastic surgeons that all potential patients be administered a rudimentary psychological examination.

    • Lack of realistic and reasonable expectations is an absolute contraindication for this surgery. It is often just those patients who are not candidates for reasons of generalized obesity, skin laxity, and marginal health who are also those with totally unrealistic expectations. Despite being educated about the clear limits of liposuction, these prospective patients usually claim afterward that they were never told and would not have undergone the surgery had they known the limitations. This should serve as a clear warning to surgeons.

These are, of course, idealized indications and criteria for qualifying patients. Each surgeon views these criteria differently and individually in making decisions as to who are good candidates; however, liposuction as a lifestyle surgery is open to much abuse. As noted above, liposuction, far from being benign, minor surgery, has a mortality rate far higher than previously assumed. Surgeons may be expected to apply stricter criteria to patient selection and magnitude of fat removal in the future, as well as the surgical facility, anesthesia, and intraoperative and postoperative care.

Relevant Anatomy

Understanding and knowledge of anatomy of the hip, thigh, buttock, and knee regions are prerequisites to both the planning and execution of liposuction of the thighs and knees. This understanding includes both an artistic acquaintance with the normal ideal shapes and contours of these areas and 3D familiarity with the gross anatomy of these areas.

Externally, viewed from behind, the female form demonstrates a concavity at the waist followed by a smooth transition to the flare at the iliac crest, over which lies a fat collection referred to as a hip roll when in excess. Between the iliac crest fullness and the prominence of the greater trochanter is the depression termed the gluteal depression. This is filled to a greater or lesser degree with the gluteal muscles and fat. Fat collection over the greater trochanter is well defined, may be quite prominent, and is referred to as a saddlebag.

Posterior thigh, inferior to the buttocks, is composed of the hamstring muscles and a more diffuse layer of overlying fat. When enlarged, it is usually part of a pattern of diffuse obesity of the thigh and treated by circumferential thigh liposuction. The anterior thigh contour consists of the quadriceps muscle group and a diffuse, rather than defined and delimited, layer of fat. In all of these areas there are both a subcutaneous layer and deeper subfascial layer of fat. The medial or inner thigh takes its shape from the abductor muscles and a layer of subcutaneous fat with no real subfascial component. Skin here is also quite thin compared to the rest of the thigh.

The femoral nerve and artery and saphenous vein lie in the upper anteromedial aspect of the thigh and groin. Surgeons always should know their location in comparison to the liposuction cannulas and other instruments.

In the knee, much of the contours reflect the underlying anatomy including the femoral condyles, tibial plateau, and patella, and the muscles (quadriceps, gracilis, sartorius, hamstrings) attached to these. Localized subcutaneous fat overlies the medial femoral condyle and musculature, producing the prominent contour. While the major arteries and nerves lie deep to the investing fascia around the knee, the sural nerve and the greater and lesser saphenous veins are in the superficial fat layer and thus liable to injury in liposuction.


Contraindications are the absence of the aforementioned indications.



Laboratory Studies

Every patient must undergo an appropriate complete medical history and physical examination. A perfunctory examination and limited laboratory studies for a young and apparently healthy patient are inappropriate. Laboratory tests should include the following:

  • CBC

  • Urinalysis

  • Electrolytes (if patient is taking diuretics)

  • Chest radiograph (when none has been performed for more than 1 year or if patient has history of cigarette smoking)

  • Electrocardiogram (for men older than 40 years and women older than 50 years, unless there is a history of hypertension, stroke, arrhythmias, diabetes, cigarette smoking)

  • Pregnancy test in women of childbearing age

  • HIV and hepatitis testing

  • Accurate weight (and date of that weight) as well as measurements of the areas to be liposuctioned (If the patient's personal physician or an outside physician other than the surgeon is performing the physical examination, record weight and measurements at the surgeon's office. Patients are notorious for providing inaccurate reports of their weight and dimension measurements.)

Imaging Studies

Other than a routine chest radiograph where indicated by age, smoking history, or history of prior disease, no imaging studies are necessary in the preoperative liposuction patient. Ultrasound examinations of the fat layer before and after suctioning are interesting but expensive and unnecessary.

Histologic Findings

Histologic findings are not relevant, as surgeons are not working with tissue pathology; however, research studies pertaining to histologic changes following liposuction have been performed. Carpaneda in 1996 reported that "Histologic studies [postliposuction] disclosed extensive amounts of dead adipocytes and free fat within the aspirated area. The pockets left behind were filled with serum hemorrhagic material and evolved to the healing process. Collagen synthesis increased initially then followed by gradual decrease and a remodeling process. Our findings suggest that liposuction techniques preserve some vessels and nerves, but the final resolution may take several months or years, depending on the amount of tissue damage."[11]



Medical Therapy

Assuming that the patient meets the criteria for consideration for liposuction surgery, medical therapy such as diet and exercise are not indicated.

Surgical Therapy


Preoperative Details

Preoperative preparations

  • Discontinue the following:

    • Smoking

    • Aspirin, aspirin-containing medications

    • Ibuprofen

    • Vitamin E

    • Garlic preparations and other herbal remedies

    • Diet medications for 2 weeks before surgery

    • Alcohol for 2 weeks before surgery

    • Medications in appendix I for 2 weeks before surgery

  • Wash areas to be liposuctioned with antibacterial soap or cleanser beginning 2 days prior to surgery.

  • Make transportation and aftercare arrangements.

  • Decide on location, either hospital operating room, hospital-attached or free-standing ambulatory surgery center, or office surgical facility.

    • Whether liposuction should be an inpatient or outpatient surgery has become controversial because of complications and the reported mortality rate. In several states it has led to attempts at legislative intervention to define how, when, and where liposuction is to be performed, as well as volume guidelines.

    • The general consensus, still leaving the final decision up to individual physician, is that an otherwise well patient having liposuction of less than 1500 mL volume can undergo the procedure as an outpatient.

    • Instructions for observation at home must be clear, and an at-home caregiver should be present at all times for the first 24 hours. For more than 1500 mL volume, patients should remain overnight in an extended care facility that allows for monitoring of vital signs, intake and output fluid management, and observation by professionals.

    • Safety issues aside, many, if not most, patients are more comfortable spending their first night after surgery in a facility with professional care and access to management of pain and nausea.

    • The growth of ambulatory surgery has paralleled the growth of cosmetic plastic surgery. With it has come the creation of the office-based surgical facility. When such a facility is constructed and staffed in accordance with standards set by various licensing and certifying organizations (Accreditation Association for Ambulatory Health Care [AAAHC], American Association for the Accreditation of Ambulatory Plastic Surgery Facilities [AAAAPSF], Medicare), it is a safe, appropriate location for liposuction.

    • However, there are many examples of poorly equipped and staffed facilities functioning as ambulatory surgical centers but limiting expenses to be competitive at the peril of patient and physician. Competition is good and healthy, especially when it benefits the public by offering options, alternatives, and lower prices; however, when competition spurs cutting corners and increasing risk, no one benefits.

Patient marking

Prior to sedation or induction of anesthesia, make accurate and precise skin markings with patient in a standing position. If possible, use a full-length 3-way mirror to make these topographical maps, as it will give the patient the opportunity to view all of the areas to undergo liposuction and to point out areas of individual concern. Use either a sterile surgical marker or clean indelible marker (Sharpie).

Especially for the inexperienced liposurgeon, for thigh and knee liposuction it is useful to mark in a consistent fashion. Begin by delineating the entire region, including superior and inferior limits of the thigh and knee, medial and lateral lines, and anterior and posterior. Mark landmarks such as the gluteal crease and popliteal line. Next, outline natural indentations, dents, and depressions. Finally, outline bulges to be reshaped with concentric circles that, like a topographical map, delineate the maximum to minimal projections, thus the relative amount of liposuction for the area. If the surgeon plans to liposuction the entire thigh circumferentially, then markings should demonstrate this plan as well.

While one cannot always be sure of the exact number and location of incisions, for liposuction of the thighs and knees, the standard incisions (of approximately 3-mm length) are buttocks crease, lateral buttock or hip, medial groin, and medial popliteal line. As long as the incisions are kept short, skin is protected with lubrication from abrasive cannula trauma, and closed with subcuticular sutures only, incisions can be placed almost anywhere they are needed to perform the liposuction and remain inconspicuous.

Intraoperative Details


General, spinal, and epidural with tumescent or superwet infiltration: General, spinal, and epidural anesthetics require an anesthesiologist or nurse anesthetist and provide the greatest level of control and patient comfort. The author prefers general anesthesia for all but the most localized and limited areas of liposuction. The presence of an anesthesiologist maintains patient comfort and manages and monitors fluids; this is crucial for patient safety and the surgeon's peace of mind. There is no question that this increases costs.

  • Tumescent only: The tumescent technique, with or without sedation, is another option with many proponents. In the tumescent technique, tumescent solution is injected under pressure (either with a pressurized fluid bag or using a compressed gas-pressurized infusion apparatus, as shown below) until the endpoint is reached of tissues being firmly uniformly distended. Tumescent fluid infusate is the primary mode of anesthesia.

    Cabot high-pressure infusion pump for infusing tum Cabot high-pressure infusion pump for infusing tumescent fluid.
  • Local: Except for limited areas, pure local anesthesia, usually defined as a field block using 0.5-2% lidocaine with adrenaline, is not possible because of the load of anesthetic agent required. Therefore, local anesthesia in liposuction refers to the "tumescent technique" as described by Klein.[12] As described above, the dilute lidocaine and adrenaline solution serves to provide both anesthesia and hemostasis. For many liposuctionists, no other forms of analgesia or anesthesia are used.

  • Local with sedation: Another option is to combine the tumescent method with oral and/or parenteral sedative agents. This may include a preoperative sedative cocktail as well as intravenous opiates, sedative agents such as Valium or Versed, and Propofol by drip or bolus. Where sedation is used, the author strongly recommends that these be administered and the patient monitored either by an anesthesiologist or certified registered nurse anesthetist (CRNA), not the surgeon and circulating nurse.

Intraoperative fluid management

Intraoperative fluid management is critical. As a significant portion of the tumescent/superwet solution is absorbed, consider it in the calculations of intravenous intraoperative and postoperative fluid needs. In addition to the usual intraoperative monitoring devices, the patient undergoing liposuction needs to have a secure intravenous line capable of delivering large fluid volumes if necessary. An indwelling Foley catheter to monitor hydration may be necessary as well. Also monitor core body temperature, as these patients can and do have major reductions in body temperature during the surgery.


This is a matter of surgeon preference. The author prefers the patient in a prone position for liposuction of the posterior thigh, saddlebag, hip roll, banana roll, upper and lower medial thigh, and medial knee, followed by the supine and frog-leg position for the remainder of the inner thigh and knee, as well as the anterior thigh and anterior knee.


Sequential pneumatic compression devices are used in all patients. Every effort is made to maintain core body temperature through use of warmed intravenous fluids, warmed wetting solutions, and warming devices, since the degree of skin area exposed and the use of fluids rapidly encourages loss of body heat.

Following induction of anesthesia, if the prone position is desired first, turn the patient or leave him or her in the supine position. Make multiple stab incisions in the desired locations with a No11 scalpel blade (shown below). As the author performs virtually all liposuction procedures under general endotracheal anesthesia, incision sites are not anesthetized. Infusion incisions should be the same as those planned for use in the liposuction procedure. If a small area is performed under a local infiltration anesthesia, the stab incision site(s) is infiltrated with 0.5% lidocaine with 1:200,000 epinephrine via syringe and a 25-27–gauge, 1.5-inch needle. These incisions serve both for infiltration of the wetting solution as well as for liposuction access.

Liposuction, thigh and knee. Making incisions for Liposuction, thigh and knee. Making incisions for tumescent infusion.

Next, in the routine liposuction case, the surgeon injects tumescent or superwet solution under pressure, as shown below, either to the point of tissue turgidity, if the tumescent method is used, or to a predetermined volume if the superwet method is applied. Instill infusate at all 3 anatomic levels of fat: prefascial, intermediate, and superficial. The volume injected depends on whether the surgeon is a proponent of the tumescent or superwet method. For the former, the volume of fluid injected is approximately 3 mL or greater for each milliliter of aspirate that the surgeon expects to extract from the area to be injected. For the latter (superwet), approximately 1-1.5 mL/mL of aspirate is injected.

Liposuction, thigh and knee. Infusing tumescent fl Liposuction, thigh and knee. Infusing tumescent fluid.

Before infiltration, the author paints the area with Betadine (povidone iodine) solution, dons sterile gloves, and drapes the operative field for injection. Following injection, surgically prep the patient with Betadine soap and paint and drape appropriately. Blanching of the tissues occurs over the succeeding 10-20 min. The surgical procedure should not commence until blanching is present.


Liposuction cannulas come in an almost unlimited number of designs, sizes, and shapes. Selection is a matter of personal preference. Experienced liposurgeons rarely use cannulas wider than 4.6-5 mm as they are overly aggressive and can produce dents and divots rapidly. The author prefers both the triple-hole accelerator tip cannulas and the Mercedes Tip cannulas of various sizes from 2-4 mm internal diameter, as shown below. Both long and short versions are used. They are attached by sterile hose to the liposuction machine, shown below. A multitude of such nonultrasonic machines are available.

Liposuction, thigh and knee. Mercedes tip design l Liposuction, thigh and knee. Mercedes tip design liposuction cannulas.
Standard liposuction machine. Standard liposuction machine.

With the patient in the appropriate position, using the existing incisions and adding incisions where necessary, introduce the cannula, as depicted in the image below. The author usually begins with the larger diameter accelerator cannulas (3 and 4 mm) for both pretunneling and suctioning in the deep compartment first and then in the intermediate level to approximately 0.5 cm beneath the skin. Intermediate layer liposuction generally results in significant skin contraction without the risks (bleeding, dents, irregularities, visible postoperative "tracks," lines of the cannulae) of superficial liposuction. Where significant skin laxity exists or is anticipated and additional skin contraction desired, the author liposuctions with 2-mm cannulas in the superficial layer (1-2 mm beneath skin).

Liposuction, thigh and knee. Introducing the cannu Liposuction, thigh and knee. Introducing the cannula.

The endpoint is both visual and palpable. The visual endpoint is when the desired contour has been reached. This is confirmed by a combination of pinch test (comparing preoperative with postoperative thickness), palpation of smoothness, and amount of fat removed.

Close wounds with an intradermal monofilament absorbable suture (4-0 Monocryl [poliglecaprone 25]) and cover with a clear adherent sterile dressing (Op-Site or Bioclusive dressing). No drains are used. Treated areas are occasionally covered with a nonadherent foam material (TopiFoam silicone-gel adhesive foam pad) for somewhat greater direct compression in certain areas. Do not use taping or Reston foam. Apply a compressive garment.

Under some circumstances, when the volume of fat to remove is large or if the area is extremely fibrous, use UAL for the initial softening and liquefaction of the deep fatty layer. The author prefers the Mentor Contour machine, although the LySonix ultrasonic liposuction device has been used previously. The author's preference is based on the Mentor device's protective sleeve and continuous irrigating system that allows ultrasonic liposuction with a small (3-4 mm) incision rather than the somewhat larger incisions necessitated by the size of the skin protectors used with the LySonix device.

Postoperative Details

Following surgery, patients spend an average of 1-1.5 hours in recovery (postanesthesia care unit) before discharge to their overnight room or home. Normally, monitoring for the first 12-24 hours consists of vital signs and intake-and-output. With tumescent or superwet techniques, fluid management with intravenous replacement is reduced. Studies indicate that approximately 20% of wetting solution is not absorbed. Absorption is approximately 1 mL of injected wetting solution per milliliter of fat aspirated. Remaining fluid needs are delivered with intravenous replacement both intraoperatively and postoperatively and by mouth during the postoperative period. In addition to stable pulse and blood pressure, urinary output of 1-2 mL/kg/h is the goal. Blood transfusion is rarely necessary and, if indicated, is usually anticipated; autologous blood previously has been set aside for transfusion as packed red blood cells.

Bloody drainage

For approximately 48 hours after surgery, especially during the first 24 hours, there is a significant amount of bloody drainage from the incision sites. This occurs even though these wounds are sutured closed and covered with a presumably watertight dressing. While some liposurgeons advocate a conscious active evacuation of fluid from the wounds at the completion of surgery or even insertion of drains, the author has not found this either necessary or advantageous. Warn patients and their caregivers to expect this or they will be understandably frightened and assume that something has gone awry.

Avoid heat and hot water

Encourage early ambulation and activity postoperatively. Patients may shower beginning the day following surgery, but baths are not allowed. Shower water should be lukewarm to avoid possible burns in the liposuction regions. Liposuctioned areas will be numb or at least have much reduced sensibility. Therefore, they are liable to burn injuries. Advise patients to avoid heat packs, heating pads and hot water bottles, hot tubs or even hot baths, and sun tanning, naturally or with tanning beds. Avoid these various activities for several months or until skin sensation has returned to normal.

Compression garments

Patients should have multiple (at least two) compressive garments to allow one to be washed while having a clean one at all times. Compressive garments are used continuously for a minimum of 3-6 weeks (surgeon's preference) and are followed by a garment of lesser compression (and better fashion) such as snug-fitting bike shorts (for patients who have had upper thigh liposuction only) or leotards for those who have had more complete thigh and knee procedures.


Additionally, when areas are comfortable to the touch, prescribe a combination of lymphatic massage, occasional ultrasound treatments, and self-compression using a standard rolling pin. This process continues for up to about 3 months as tissues progress through the normal phases of healing, deep scar tissue formation, and remodeling of scar tissue.

Return to activity

Return to full normal activity is individually based and depends on a variety of factors including pain tolerance, motivation, and need to return to work. On average, patients are able to resume most normal activities within 1-2 weeks. Some patients are quite active within a matter of days.


Patients who spend the night in the surgery center are examined the morning after surgery and then discharged if doing well. Day patients, discharged home from the recovery room, are seen the following day in the office for an initial follow-up visit. Thereafter, patients are seen at 1-week intervals for the next 3 weeks. After that, follow-up office visits are at 3, 6, and 12 months after surgery.

Photographs and measurements are taken at the 1-, 3-, 6-, and 12-month visits.

The process of deep scar tissue development and resolution takes as long as 6 months.


Risks and complications of liposuction may be divided into the risks generally associated with surgical procedures and those that are more specific to liposuction.[13, 14]

General risks of surgery

See the list below:

  • Bleeding: Significant bleeding is not really considered a risk of liposuction; however, large or megavolume liposuction can encompass the loss of a sizable amount of blood, requiring transfusion.

  • Seroma is infrequent in the thighs and knees and usually self-limited, thus these require no treatment.

  • Infection is uncommon but fat has poor resistance to infection. The physician needs to be cognizant of and able to recognize necrotizing infection.

  • Scarring: Incisions usually heal uneventfully; however, the patient can develop hypertrophic scarring. Additionally, inadvertent injury to overlying skin through superficial liposuction or UAL can produce hypertrophic scarring.[15]

  • Anesthetic risks vary, of course, with the type of anesthesia selected by the surgeon.

    • Probably most plastic surgeons use general anesthesia administered by either a physician anesthesiologist or a CRNA, together with tumescent infiltration, for all except limited areas of liposuction. For an in-depth discussion of general anesthetic risks, refer to a textbook of anesthesia.

    • In broad terms, beyond the "chipped tooth, corneal abrasion" sorts of risks, the major risks include fluid overload with congestive heart failure and pulmonary edema, toxic effects of anesthetic agents, lidocaine toxicity (where a tumescent fluid is also used) including seizures and cardiac arrhythmia, cardiac arrest, and death.

    • When tumescent infiltration with or without sedation is the chosen form of anesthesia, the risks are similar to those of general anesthesia in terms of fluid overload, lidocaine toxicity, and excessive sedation with respiratory and/or cardiac arrest.

    • Finally, on those occasions when spinal or epidural anesthesia is used, additional risks include spinal headache, persistent spinal fluid leak, infection, "high spinal anesthesia" with respiratory depression, and cord injury.

  • Phlebitis and pulmonary embolus: Despite using preventive measures including sequential compression devices, phlebitis and deep vein thrombosis (DVT) occur, as do subsequent pulmonary emboli.

Specific liposuction risks

See the list below:

  • Skin necrosis: As mentioned earlier, superficial liposuction, overzealous subdermal fat thinning, liposuction in areas of prior incision scars, and UAL as well as idiopathic causes can result in partial-thickness and full-thickness skin necrosis following liposuction. These usually are best treated conservatively where possible. Larger areas of necrosis may require excision and grafting.

  • Burns: Particularly in the use of older and high-power UAL devices, burns can occur. Treatment is the standard care for such a depth injury.

  • Hypertrophic scarring: This can occur as mentioned above.

  • Fat emboli: These are less common than imagined although there have been reports in the literature. Some liposurgeons use prophylactic alcohol therapy.

  • Fluid overload/pulmonary edema: This is a significant risk requiring appropriate fluid management and monitoring. When fluid overload occurs, it requires immediate appropriate management.

  • Drug toxicity: The patient can react to lidocaine, bupivacaine, or epinephrine.

  • Unfavorable esthetic results: The patient may experience asymmetry, divots and dimpling, lumpiness and waviness, and skin laxity.

Outcome and Prognosis

Results of liposuction of the thighs and knees, particularly the outer thigh and knee, usually are very favorable. With reasonable patient selection and conservative treatment, even inexperienced liposurgeons can expect a good result. The desired result in the outer thigh is a smooth contour less the "saddlebag" bulge, without divots, indentations, or skin laxity. Posteriorly, at the thigh-buttock junction, ideally a defined break should be apparent between upper thigh and buttock, without a roll (banana roll) at that junction.

Less forgiving are the medial and anterior thigh. In the medial thigh, where skin is quite thin and the subcutaneous fatty layer frequently not large, conservatism is key. More aggressive liposuctioning can easily result in excessive skin laxity, an appearance of skeletonization and concavity, and skin discoloration. The desired result is a smooth line from the upper border of the inner knee to the groin, with slight concavity above the knee transitioning to slightly greater fullness of the upper inner thigh, but without a bulging roll in the final 6-8 cm before the groin crease. With the heels together, the upper inner thighs should either barely graze each other or have a slight separation.

However, a study by Armijo et al indicated that liposuction-assisted medial thighplasty can be an effective means of medial thigh contouring in patients with lipodystrophy related to aging or a large weight loss. The procedure described, performed on 45 patients in the study, involves the following[16, 17] :

  • L-shaped anterior markings

  • Superwet infiltration

  • Circumferential combined superficial ultrasound-assisted/suction-assisted liposuction

  • Predesigned and patterned skin excision and layered closure

Advantages to the procedure, according to the investigators, include nerve and lymphatic preservation, blood loss reduction, and, through maintenance of the saphenous vein system, aversion of wound breakdown and skin loss.[16]

Especially for the inexperienced surgeon, it is best to avoid the anterior thigh. When it is necessary to liposuction the anterior thigh, perform this as part of a circumferential thigh liposuction. Be conservative; undercorrection and leaving fat behind is better than having even the slightest concavity along the thigh's anterior curvature.

Long-term results are mixed. While the fat removed from individual locations does not return, patients do have a tendency to gain weight following liposuction in greater than ideal percentages. Where large-volume liposuction has been part of total body recontouring, weight gain is common. However, where liposuction has been used for its intended purpose of shaping isolated fat collections, results and long-term prognosis are excellent.

Future and Controversies

As surgeons gain greater understanding of fat metabolism and means of controlling weight gain, liposuction to contour the results of heredity, with chemical management of weight fluctuations, may become a routine task for the cosmetic physician.

Lifestyle cosmetic procedures such as liposuction may become part of the comprehensive area of medicine termed "cosmetic medicine and age management." Looking good, feeling good, and living longer and more productively may become a reality.

For excellent patient education resources, see eMedicineHealth's patient education article Liposuction.