Glycative Stress Research
Online edition : ISSN 2188-3610
Print edition : ISSN 2188-3602
Received : February 5, 2020
Accepted : March 31, 2020
Published online : June 30, 2020
doi:10.24659/gsr.7. 2_116

Original article

Prior bariatric surgery is effective on morbidly obese patients following total
knee arthroplasty.
Shingo Iwata 1, 2), Akeo Hagiwara 2), Keiichiro Nakamae 3)
1) Department of Surgery, Takeda General Hospital, Kyoto, Japan
2) Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
3) Department of Diabetes and Endocrinology, Takeda General Hospital, Kyoto, Japan

Abstract

It is reported that bariatric surgery is effective in patients with morbid obesity, especially when there is difficulty
in weight reduction or rebound phenomenon from therapy including internal medicine. Generally orthopedic operations
for patients with knee osteoarthritis (both sides) and a high body mass index (BMI) over 50 kg/m 2, have a risk of postoperative complications and sometimes functional improvement cannot be expected. We report here a case where total knee
arthroplasty (TKA) was successfully performed for both sides after the weight reduction by laparoscopic sleeve gastrectomy(LSG). A 60-year-old morbidly obese male (BMI 50.8 kg/m 2 ) was referred for bariatric surgery consultation. The patientcomplained of continuous severe knee joint pain, and was ordered to undergo weight reduction by an orthopedic surgeon
before performing TKA, and then introduced to our hospital. Past and present illness included epilepsy, and accompaniedwith obesity-related complications; hypertension, dyslipidemia, fatty liver, sleep apnea syndrome, and type 2 diabetes (borderline). The educational admission was conducted aiming to reduce the risk of LSG and learn adequate lifestyles for weight
reduction therapy. By the team medical treatment for weight reduction, including LSG, the operation was successful and his
post-operative condition was maintained; BW 84 kg 8 month after LSG, a 58 kg reduction from the first visit. Ten months
after LSG, a left side TKA was performed, and 4 months later, a right side TKA performed. After LSG, obesity-related
complications were markedly improved. Furthermore, after TKA, knee pain was relieved, knee joint swelling disappeared,
and his walking distance was extended. This case of morbid obesity showed that successful weight reduction was obtained by
pre-performing LSG, thus reducing the risk of TKA and protecting against complications, and the activity of daily life andquality of life was improved by as a result of the team medical treatment.

KEY WORDS: morbid obesity, weight reduction before surgery, laparoscopic sleeve gastrectomy (LSG),

		bariatric surgery, total knee arthroplasty (TKA), knee osteoarthritis

Introduction
In patients with obesity and metabolic syndrome,oxidative stress and glycative stress are generally high. The
numbers of these patients have increase nowadays, and it
became a social problem against which it's necessary totake measures. Medical therapy alone is often ineffective forpatients with morbid obesity and sometime induces a rebound.
Especially for these patients, on the other hand, bariatricsurgery is reported to be effective 1). It is known that bariatricsurgery reduces prevalence of obesity-related complications
and improves the quality of life (QOL) and mortality 2- 4). With
the worldwide increase in the obese population, the numberof bariatric surgery procedures has increased 5). On the other
hand, although bariatric surgery is still not generalized andrelated reports 6) are few from Japan, laparoscopic sleeve
gastrectomy (LSG), as a bariatric surgery procedure, hasbeen covered by medical insurance in Japan for patientswith morbid obesity since 2014, and the number of patients
undergoing this surgery tends to be increased steadily.
Insurance coverage requirements in Japan are as follows:
Even if medical therapy for more than 6 months is performed,
weight reduction is insufficient; Body mass index (BMI) is
35 kg/m2 or more; A patient accompanied with one or more of

Corresponding to: Shingo Iwata, MD, PhD
Department of Surgery, Takeda General Hospital
28-1 Ishida Moriminami-cho, Hushimi-ku, Kyoto 601-1495, Japan
TEL: + 81-75-572-6331 FAX: + 81-75-571-8877 e-mail: s-iwata@takedahp.or.jp

Co-authors: Hagiwara A, hagiwara4f@gmail.com ;Nakamae K, nakamae@mub.biglobe.ne.jp_ 116 _

Glycative Stress Research 2020; 7 ( 2) : 116-122(c) Society for Glycative Stress ResearchGlycative Stress Researchtype 2 diabetes mellitus (T2DM), hypertension, dyslipidemia,
sleep apnea syndrome (SAS). However, obesity is anexacerbation factor for the locomotor disorders including
knee osteoarthritis (OA) or lumbar joint disorders. In thepresent report, we introduce a case of super obesity with knee
OA, where bariatric surgery decreased the high operation
risk due to obesity, followed by total knee arthroplasty(TKA).

Case presentation
The patient: A male at the age of 60 years.
Chief complaint: To receive bariatric surgery.
Anamnesis: At the age of 20, body weight (BW) 90 kg; At
the age of 28; epilepsy attack and medication started; At theage of 30, BW 100 kg; At the age of 35, enucleation of brain
tumor (BW 110 kg); At the age of around 50, knee painincreased, consulted an orthopaedist and diagnosed as knee
OA; At the age of 54, BW 130 kg and consulted an internist.
Tried weight reduction, at first 20 kg reduction then rebounded
to over 140 kg. Knee symptoms deteriorated, accompanied
by back pan, walking distance decreased. The orthopaedist
told the patient that TKA should be taken into consideration
but is difficult unless BW is reduced to less than 90 kg. The
patient tried conservative weight reduction but the result was
only 1 kg weight reduction. Since obesity was physical-therapy
resistant and accompanied with SAS, hypertension and fatty
liver, the internist recommended bariatric surgery and thenintroduced him to our hospital.
Past history: At the age of 3, epilepsy attack, diagnosed as
benign brain tumor.
Operation history: At the age of 35, enucleation of brain
tumor, no attack after the surgery.
Family history: Mother; hypertension, subarachnoid
hemorrhage.
Life history: Smoking history, none: Drinking history, none.
Medication history: For both-side knee pain, loxoprofen
sodium hydrate 120 mg/day, rebamipide 200 mg/day,esomeprazole magnesium hydrate 20 mg/day, and mosapride
citrate hydrate 15 mg/day; for epilepsy attack, aripiprazol 9~15
mg/day, carbamazepine 800 mg/day, diazepam 20 mg/day, andeszopiclone 3 mg/day; for hypertension, azilsartan 10 mg/day
and controlled release nifedipine 60 mg/day.
Clinical data of the first visit: Morbid obesity was recognizedwith a height; 167.4 cm, BW; 142.3 kg, BMI; 50.8 kg/m2 andblood pressure; 163/78 mmHg (under medication). Endocrine
tests excluded secondary obesity. Electro-cardiogram shows
within normal range. Computed tomography showed noabnormal finding, except fatty liver.
Upper GI endoscopy: No abnormal finding. Helicobacter
pylori negative.
Colonoscopy: Four polyps were noted and, performing
polypectomies, turned out to be adenoma by pathologicaldiagnosis.
Pulmonary function tests: % vital capacity (%VC) 90.2%
and forced respiratory volume 1.0 (sec) % of Gaensler (FEV
1.0 %-G) 80.96%. Function recovered to the level with %VC
98.9 % and FEV 1.0 % - G 82.05 %. Spirogram data alsoameliorated by the weight reduction before the surgery.

Ethical standard
Before starting this surgery, a written consent was
obtained from the patient. This study was implemented incompliance with the Helsinki Declaration (as revised in
1975, 1983). This study was approved by the ethics committeeof this hospital

Aims for the therapy
The aims of the educational hospitalization were as
follows: 1) weight loss and getting into good health forthe operation 2) evaluation of the capability for the patient
to endure dietary restrictions 3) guidance for appropriate
eating manners 4) observation and assessment of behavioral
patterns of having low caloric diet including a formula meal5) assessment to judge if he would be able to withstand more
severe diet control post-operation 6) loss of weight to reduce
the quantity of visceral fat so that the lateral division of liver,which was compensatory hypertrophy due to fatty liver,
could be reduced to as little as possible for the surgery to be
conducted safely.

Flow from the educational admission,at the operation and postoperative course;

Figure 1 shows the time course and changes of BW. In
the first admission among the four educational admissions,patient’s BW reduced from 142 kg to 132 kg in one monthby the diet therapy starting from 1,000 kcal/day. In thesecond admission, after one week period of discharge, theBW maintained at 130 kg without increase, the diet therapy
started again from 1,000 kcal/day; BW reduced from 130 kg
to 125 kg. In the third admission, BW reduced from 124 kg to
118 kg by 1,000 kcal/day diet. In the fourth admission, BW
reduced from 118 kg to 114 kg, and BMI became less than
40 kg/m2 by 800 kcal/day diet additionally using the formuladiet. The patient adhered to dietary instructions during the
educational admission and BW was reserved as the samelevel after discharge. Then we judged as indications forbariatric surgery and prepared for the fifth hospitalization.
The weight reduction was successful from 142.3 kg (BMI
50.8 kg/m2 ) at the first visit to 114.0 kg (BMI 40.7 kg/m2 )by 28 kg as a result of the diet and exercise therapy during
four admissions of 3 weeks each.
The visceral fat area was measured at the firstadmission and just before the surgery by using a visceral fat
measuring device (HDS-2000; Dualscan, Omron HealthcareCo., Ltd., Kyoto, Japan) 7). Visceral fat area reduced from 243
cm2 to 183 cm 2. Table 1 shows the data of blood biochemical
examination at the first visit and just before the operation;
noted abnormal values in hepatic enzymes. LSG was
performed 4 months after the first educational admission.
LSG 8) : Under a general anesthesia, the procedure
involved a longitudinal resection of the omentum majus
starting from the antrum at the point 4 cm from the pylorus ingreater curvature of the stomach and finishing at the His angle.
After resection of the omentum, the stomach was resected on
the side of greater curvature by a surgical stapling device withthe guidance of an endoscope. Thus, after surgically removing_ 117 _

Bariatric Surgery for Total Knee Arthroplasty Complicated by Morbid Obesity

160
140

Body weight (kg)

120
100
80
60
40
20
0
0

100

200

300

400

500

700 (Days)

600

Fig. 1. Clinical course (Changes in body weight)

LSG, laparoscopic sleeve gastrectomy; TKA, total knee arthroplasty.

Fig. 1.

Table 1. Laboratory data on first visit, preopeartive day 1, and postoperative 17 months.
WBC
Hb

Hct
Plt

TP

Alb

T-Bil
AST

ALT

ALP

LDH

γ-GTP
BUN
CRE

T-CholHDL
LDL
TG

HbA1c [NGSP]CRPFirst visit

Pre-LSG 1

Post-LSG 17 M

/μL

5900

4800

3300

g/dL

14.8

14.5

13.4

%
x10 4/μL

45. 3

43.4

40.0

22. 5

18.6

17.7

g/dL

7.8

7.6

6.7

g/dL

4.7

4.6

4.0

mg/dL

0. 5

0.8

0.6

IU/mL

53

70

17

IU/mL

81

124

16

IU/mL

340

237

206

IU/mL

221

167

128

IU/mL

315

158

67

mg/dL

12

8

11

mg/dL

0.80

0.71

0.72

mg/dL

189

191

177

mg/dL

78

67

86

mg/dL

86

110

91

mg/dL

209

87

56

%

5.7

5. 3

5. 2

mg/dL

0.45

0.71

0.09

Pre-LSG 1, day 1 before LSG; Post-LSG 17 M, 17 months after LSG; LSG, laparoscopic sleeve gastrectomy: WBC, while blood cell; Hb,hemoglobin; Hct, hematocrit; Plt, platelet; TP, total protein; Alb, albumin; T-Bil, total bilirubin; AST, aspartate transaminase; ALT, alaninetransaminase; ALP, alkaline phosphatase; LDH, lactate dehydrogenase, γ GTP, gamma glutamyl transpeptidase; BUN, blood urea nitrogen;
CRE, creatinine; T-Chol, total cholesterol; HDL, high-density lipoprotein cholesterol; LDL, low-density lipoprotein cholesterol; TG,
triglyceride; NGSP, natinal glycohemoglobin standardization program; CRP, C-reactive protein.

_ 118 _Glycative Stress Researcha stomach section, a small diameter gastric tube, which is areduced stomach portion, was produced. It was confirmedby the endoscope that there was no bleeding, nor contraction
within the stomach, after reinforcing the staple-line.
Post-operative complications were not observed, BW
reduced to 99 kg, and then the patient was discharged. Afterdischarge, his BW increased to 103 kg. This is because hishome was away from our hospital, he could not exercise due
to knee joint pain, and no close hospital was available forpost-operative bariatric surgery care. Thus, he was admitted
again for diet and education. At the time when BW was
reduced to 85 kg (BMI 30 kg/m 2 ), less than 90 kg average,
TKA of the left side was performed, followed by TKA ofright side 4 month later.
According to the Japanese Orthopedic Association(JOA) score proposed by JOA, the treatment outcome of thepatient was evaluated at the first visit, after LSG and after
TKA. JOA score is a judgment criteria that consists of 4
items (100 point maximum); “ Pain on walking”, “Pain on
ascending or descending stars”, “Range of motion”, and“Joint effusion” 9).
Scores were 45/100 points at the first visit, 55/100 points
10 month after LSG and 90/100 pints after both-side TKA,
indicating his joint symptoms were markedly improved. The
state in detail at the first visit seemed as follows: He wascapable of walking for 100 m to 500 m distance with pain;He was capable of going up and down stairs, slowly step bystep, depending on a handrail with pain; The range of motionof the knee joint was more than 110 degree; Joint punctures
were often needed.
After LSG and before TKA, his condition improved; He
was capable of going up and down stairs without assistancebut with pain; He was free from pain while going up anddown stairs with the use of a handrail; Joint punctures were
only sometimes necessary. These findings indicated thatjoint disorders induced by excess BW could be efficiently
ameliorated to some extent only by performing LSG.
After both-side TKA, his condition improved markedly;
He was capable to walk more than 1 km distance; He wascapable of going up and down stairs without pain; His rangeof motion in the knee joint widened and he was capable ofsitting sideways and in cross-legged position; Hydrarthrosisor
swelling were not observed.
These findings indicated that joint disorders induced byexcess BW could be efficiently ameliorated by performing
LSG, although obesity treatment alone might also improve
his state.
At one year and 5 months after LSG, his BW was 80 kg,
a 62 kg reduction from the first visit, height 168.9 cm (tallerthat that at the first visit due to better posture), and BMI 28.0kg/m2. Blood examination showed that liver dysfunction was
ameliorated ( Table 1).
Visceral fat area of the patient markedly decreased to
53 cm2 measured by HDS-2000. As shown in Fig. 2, visceralfat reduced markedly and waist circumference shortened.
He became capable of walking without the assistance of acane and no analgesics were necessary for knee joint pain.
Blood pressure turned out to be normal without using antihypertensives.
Regarding to his sleep state, he was suspected to havesevere SAS at the first visit with the Apnea Hypopnea Index(AHI): 54.7 evaluated by polysomnography but no abnormal
findings were noted by otolaryngological examination. At
this time, SAS was relieved by a weight reduction to AHI:
5.0 and he was free from sleep disorders: no medicationnecessary.

Fig. 2. Abdominal computed tomography.
a) On first visit. b) 17 months after laparoscopic sleeve gastrectomy. Remarkable decrease of visceral fat is found after surgery.

Fig. 2.

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Bariatric Surgery for Total Knee Arthroplasty Complicated by Morbid Obesity

Discussion
Obesity is an exacerbation factor of knee OA. While knee
pain causes difficulty in exercise therapy thus accelerating theobesity stage, the patients fall into the vicious cycles 10, 11).
In this case, which is very typical, he may go on the path ofdeterioration as it is, and could not avoid life in a wheel chair.
TKA is an effective operation for knee OA in obese patientslike a present case, however it is not easy to determine theoptimal timing of the operation. Most obese patients areaccompanied with obesity-related disorders, which are
known to induce complications after TKA operations, i.e.,
infection, delayed wound healing, deep vein thrombosis, andpulmonary thromboembolism 12-17).
In obese patients, since insulin resistance or
hyperglycemia inhibits the function of white blood cells, thus
weakening immune function and vascular tissue, it is said
that there are many complications related to surgical wounds
18-22). Therefore, several reports 23-30) recommend that patients
perform TKA after weight reduction in cases of morbid
obesity, resulting in less post-operative complications andimprovement of the knee joint functions. However, there aresome controversial reports 31-34).
For example, Li W et al. 33) reported that pain relief
effects in patients without weight reduction is not different
from patients who were operated on after weight reduction,although obese patients were often instructed to reduce BW.
It is not easy to perform the exercise therapy for morbid
obesity patients suffering from arthralgia, while, of course,
weight reduction is better conducted as much as they possibly
can. There may be a case whose joint conditions worsen
while taking time for weight reduction therapy. It is said that,
if patients can undergo the operation, he could expect earlyrecovery of joint functions and continue to deal with obesity.
It’s possible to interpret, from this report, that obese patients
can obtain the same level of pain relieving effects as patientswith normal BW. However, we cannot conclude that preoperative weight reduction is not necessary because obesity
augments the inflammation risk after the joint replacement.
The risk of complications after TKA is more frequent inpatients with high BMI 12-17), and it is reported that, especiallyregarding super-obese patients (BMI > 50 kg/m2 ), the resultsof orthopedic surgery are better when the operations are
performed after weight reduction 16, 17). In this case with a
BMI over 50 kg/m2, the surgical procedure became lessdifficult because TKA was done after weight reduction.
We expected less frequent post-operative complications
and more marked improvement of joint functions. Actually,
no complications were noted and the functions improved.
However, there are still controversial points before conclusion
about the significance of bariatric surgery before TKA.
More prospective studies with higher levels of evidence aredesired 35).
In Japan, the number of the bariatric surgery operations
is fewer than in other countries, and also the definition ofobesity is different compared with the world standard. Thereremain problems such as whether or not TKA should be
performed after weight reduction by bariatric surgery, its
surgical indication, or timing of surgery. However it takes
a time to discuss these problems, considering our ethnicity,
since it is necessary to accumulate the number of cases. In

order to establish the Japanese standard, it is desirable toconduct randomized controlled trials determining the degreeof weight reduction necessary, before the knee joint operationin morbidly obese patients.
We often see cases in which the medical therapy, if
given as an instruction against obesity, do not go well, or thetherapy does not last long even though the patient obtains
a transient weight reduction. In this case, a 20 kg weight
reduction was once successfully noted, but the BW increased
more than the previous value. The patient has achieved only
1 kg reduction after the re-trial therapy. On the other hand,
we can say that bariatric surgery is a reliable method ofweight reduction.
Motivation is important for obesity therapy. By aiming
a clear purpose of the orthopedic surgery in this case, patientcarried out the pre-operative weight reduction steadily and led
to perform LSG. Even in the case of severe obese for whom
exercise therapy was difficult to perform due to orthopedic
diseases affecting activities of daily living and QOL, bariatricsurgery was shown to efficiently improve the disorders
induced by excess weight 36-38). Furthermore, bariatric surgery
has great benefits from the view point of healthcare economy
since obesity-related complications can be improved andmedication ceased 39, 40). Insurance coverage of LSG in Japanapplies to obese patients accompanied with one of the below
disorders; T2DM, hypertension, dyslipidemia and SAS, and
LSG may be effective on the severely obese with orthopedic
diseases.

Conclusion
This case showed that the surgical operation by LSG
can successfully reduce BW and improve the function of
locomotor disorders even in the case of morbid obesity which
was resistant to weight reduction by non-operative treatment,
and possibly widened the range of orthopedic surgicalindication so that we can expect a more radical treatment.

Conflict of interest_ 12 0 _The authors have no conflict of interest in this study.

Glycative Stress Research

Reference
1) Sjöström L, Narbro K, Sjöström CD, et al. Effects ofbariatric surgery on mortality in Swedish obese subjects.
N Engl J Med. 2007; 357: 741-752.
2) Buchwald H, AvidorY, Braunwald E, et al. Bariatric surgery:A systemic review and meta-analysis. JAMA. 2004; 292:
1724 -1737.
3) Schauer PR, Kashyap SR, Wolski K, et al. Bariatricsurgery versus intensive medical therapy in obese patientswith diabetes. N Engl J Med. 2012; 366: 1567-1576.
4) Sjöström L, Peltonen M, Jacobson P, et al. Bariatric surgery
and long-term cardiovascular events. JAMA. 2012; 307:56-65.
5) Angrisani L, Santonicola A, Iovino P, et al. Bariatric surgery
worldwide 2013. Obes Surg. 2015; 25: 1822-1832.
6) Sasaki A, Wakabayashi G, Yonei Y. Current status of
bariatric surgery in Japan and effectiveness in obesity anddiabetes. J Gastroenterol. 2014; 49: 57-63.
7) Ida M, Hirata M, Odori S, et al. Early changes of abdominal
adiposity detected with weekly dual bioelectrical
impedance analysis during calorie restriction. Obesity.
2013; 21: E350-E353.
8) Iwata S, Hagiwara A, Kato H. Early metabolic response
after laparoscopic sleeve gastrectomy in obese diabetes.
Glycative Stress Res. 2016; 3: 186-192.
9) Okuda M, Omokawa S, Okahashi K, et al. Validity andreliability of the Japanese Orthopaedic Association score
for osteoarthritic knees. J Orthop Sci. 2012; 17: 750 -756.
10) World Health Organization. Fact sheet on obesity andoverweight (updated March 2013). http://www.who.int/
mediacentre/factsheets/fs311/en/ (accessed January 2020).
11) Leyland KM, Judge A, Javaid MK, et al. Obesity and therelative risk of knee replacement surgery in patients withknee osteoarthritis. A prospective cohort study. Arthritis
Rheumatol. 2016; 68: 817-825.
12) Amin AK, Clayton RAE, Patton JT, et al. Total knee
replacement in morbidly obese patients. J Bone Joint Surg.
2006; 88-B: 1321-1326.
13) Samson J, Mercer GE, Campbell DG. Total knee
replacement in the morbidly obese: A literature review.
ANZ J Surg. 2010; 80: 595-599.
14) Schwarzkopf R, Thompson SL, Adwar SJ, et al.
Postoperative complication rates in the super- obese hipand knee arthroplasty population. J Arthroplasty. 2012;
27: 397-401.
15) Kerkhoffs GMMJ, Servien E, Dunn W, et al. The influenceof obesity on the complication rate and outcome of total
knee arthroplasty: A meta-analysis and systematic literature
review. J Bone Joint Surg Am. 2012; 94: 1839-1844.
16) Naziri Q, Issa K, Malkani AL, et al. Bariatric orthopaedics:
Total knee arthroplasty in super- obese patients (BMI >50 kg/m2 ). Survivorship and complications. Clin Orthop
Relat Res. 2013; 471: 3523-3530.
17) Werner BC, Evans CL, Carothers JT, et al. Primary total
knee arthroplasty in super-obese patients: Dramaticallyhigher postoperative complication rates even compared torevision surgery. J Arthroplasty. 2015; 30: 849-853.

18) Kolterman OG, Olefsky JM, Kurahara C, et al. A defect incell-mediated immune function in insulin-resistant diabetes
and obese subjects. J Lab Clin Med. 1980; 96: 534 -543.
19) Krishnan EC, Trost L, Aarons S, et al. Study of function
and maturation of monocytes in morbidly obese individuals.
J Surg Res. 1982; 33: 89-97.
20) Tanaka S, Inoue S, Isoda F, et al. Impaired immunity
in obesity: Suppressed but reversible lymphocyte
responsiveness. Int J Obes Relat Metab Disord. 1993; 17:631-636.
21) Fink S, Eckert E, Mitchell J, et al. T-lymphocyte subsets
in patients with abnormal body weight: Longitudinalstudies in anorexia nervosa and obesity. Int J Eat Disord.
1996; 20: 295-305.
22) Nieman DC, Henson DA, Nehlsen-Cannarella SL, et al.
Influence of obesity on immune function. J Am Diet Assoc.
1999; 99: 294-299.
23) Parvizi J, Trousdale RT, Sarr MG. Total joint arthroplasty
in patients surgically treated for morbid obesity.
J Arthroplasty. 2000; 15: 1003-1008.
24) Werner BC, Kurkis GM, Gwathmey W, et al. Bariatricsurgery prior to total knee arthroplasty is associated withfewer postoperative complications. J Arthroplasty. 2015:
30: 81-85.
25) Kulkarni A, Jameson SS, James P, et al. Dose bariatricsurgery prior to lower limb joint replacement reducecomplications? Surgeon. 2011; 9: 18-21.
26) Sprin ger BD, Carter JT, McLawhorn, AS, et al. Obesity andthe role of bariatric surgery in the surgical management of
osteoarthritis of the hip and knee: a review of the literature.
Surg Obes Relat Dis. 2017; 13: 111-118.
27) McLawhorn AS, Levack AE, Lee Y, et al. Bariatric surgery
improves outcomes after lower extremity arthroplasty inthe morbidly obese: A propensity score-matched analysis
of a New York statewide database. J Arthroplasty. 2018:33: 2062 -2069.
28) Gong Y, Selzer F, Deshpande B, et al. Trends in procedure
type, patient characteristics, and outcomes among persons
with knee osteoarthritis undergoing bariatric surgery,2005-2014. Osteoarthritis Cartilage. 2018; 26: 1487-1494.
29) Nearing EE, Santos TM, Topolski MS, et al. Benefits ofbariatric surgery before elective total joint arthroplasty: Is
there a role for weight loss optimization? Surg Obes Relat
Dis. 2017: 13: 457-462.
30) Schwarzkopf R, Lavery JA, Hooper J, et al. Bariatricsurgery and time to total joint arthroplasty: Does it affectreadmission and complication rates? Obes Sur. 2018; 28:1395-1401.
31) Martin JR, Watts CD, Taunton MJ. Bariatric surgery does
not improve outcomes in patients undergoing primary
total knee arthroplasty. Bone Joint J. 2015; 97-B: 15011505.
32) Smith TO, Aboelmagd T, Hing CB, et al. Does bariatricsurgery prior to total hip or knee arthroplasty reduce postoperative complications and improve clinical outcomesfor obese patients? Systematic review and meta-analysis.
Bone Joint J. 2016; 98-B: 1160-1166.

_ 121 _

Bariatric Surgery for Total Knee Arthroplasty Complicated by Morbid Obesity33) Li W, Ayers DC, Lewis CG, et al. Functional gain and pain

relief after total joint replacement according to obesity
status. J Bone Joint Surg Am. 2017; 99: 1183-1189.
34) Li S, Luo X, Sun H, et al. Does prior bariatric surgery
improve outcomes following total joint arthroplasty in themorbidly obese? A meta-analysis. J Arthroplasty. 2019:34: 577-585
35) Gu A, Cohen JS, Malahias MA, et al. The effect ofbariatric surgery prior to lower-extremity total joint
arthroplasty: A systematic review. HSS J. 2019; 15: 190200.
36) Richette P, Poitou C, Garnero P, et al. Benefits of massive
weight loss on symptoms, systemic inflammation andcartilage turnover in obese patients with knee osteoarthritis.
Ann Rheum Dis. 2011; 70: 139-144.
37) Groen VA, van de Graaf VA, Scholtes VA, et al. Effects ofbariatric surgery for knee complaints in (morbidly) obese
adult patients: A systematic review. Obes Rev. 2015; 16:
161-170.
38) Hamdi A, Albaghdadi AT, Ghalimah B, et al. Bariatricsurgery improves knee function and not knee pain in theearly postoperative period. J Orthop Surg Res. 2018; 13: 82.
39) Sussenbach SP, Padoin AV, Silva EN, et al. Economic
benefits of bariatric surgery. Obes Surg. 2012; 22: 266-270.
40) MaLawhorn AS, Southern D, Wang YC, et al. Costeffectiveness of bariatric surgery prior to total knee
arthroplasty in the morbidly obese. A computer modelbased evaluation. J Bone Joint Surg Am. 2016; 98: e6.

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