Abstract
Morbid obesity is a possible mediating or moderating factor in the natural history of disabling hip osteoarthritis, often classified as an age associated single disease entity with homogeneous inter-individual and disease characteristics. In this brief we examined the baseline characteristics of a sample of 1000 hip osteoarthritis surgical cases to examine how frequently one might expect to find morbidly obese patients among a severely disabled hip osteoarthritis cohort undergoing primary or secondary hip surgery. We specifically sought to establish the extent to which this subgroup exists and whethertheir health profiles were similar or different fromunderweight cases. As well, wereviewed selected cases 65 years and youngerand prevailing literature to discern if morbid obesity is likely to increase the risk of adverse outcomes among this hip osteoarthritis subgroup. To this end, data from the available records of severely disabled hip osteoarthritis cases undergoing primary or secondary surgeryas well as the literature were scrutinized.Results show: 1) Cases of end-stage hip osteoarthritis are more likely to be overweight than of normal weight, with an equally small number of underweight and morbidly obese cases;2) In comparing the underweight and morbidly obese cases, most of the latter are likely to havehigher rates of one or more metabolic and/or other chronic health conditions, and a higher percentageare likely to be hospitalized for secondary surgeries or complications; 3) The functional status of morbidly obese candidates, is quite low, even when only young candidates are examined and many have already experienced some form of orthopedic complication; 4) Profiles of 2 superobese (BMI >50) surgical candidates reveal, evidence of extensive prior orthopedic problems, and medical comorbidities. These findings and current research data indicate patients who are morbidly obese are receiving hip joint replacements, but that this group may be at a disadvantage health wise as well as functionally.
Key words
body mass, hip joint, morbid obesity, osteoarthritis, outcomes, surgery
Introduction
The disease known as hip osteoarthritis is a commonhighly painful disabling joint disease with no known cure affecting a large proportion of the adult population [1,2]. Onepotentially preventable factor that may mediate or moderate the onset and progression ofhip osteoarthritis is obesity [3].Moreover, even though surgery to replace a diseased joint is generally successful, the presence of extremely high body weights in excess of ideal body weight[4,5]may impact the outcome of surgery for hip osteoarthritis quite negatively, rather than improving health status [5-7].
Although a negative outcome could further exacerbate the original problem, even if surgery is technically successful, very few community based endeavors exist to assist the obese hip osteoarthritis patient to attain a healthful weight, and healthy related behaviors either before or after surgery. Moreover, very few treatment centers specifically designed for those cases suffering from excess obesity are evident, even though these could potentially reduce the need for surgery, or delay this, or permit more healthful surgical outcomes at the outset. To raise awareness about this issue for the clinician and patient, this brief providesa snapshot of prevailing data that highlight the relevance ofthe aforementioned ideas.
To this end, a sizeable cohort of subjects with disabling hip osteoarthritis undergoing surgery were examined first, to discern body mass distributions in general, and rates of cases presenting with evidence of excess or morbid obesity, in particular. Cases defined as being morbidly obese, referring to cases 59-100% above their ideal weight were assessed with respect to the presence ofcomplications arising from prior surgeries, and/or the presence of comorbid health conditions, if any.In addition, given the controversy surrounding whether hip joint replacement surgery is appropriate for the morbidly obese, a systematic examination of the related literature was conducted.
We anticipated a small, but clinically important proportion ofcases with hip osteoarthritis requiring some form of primary or secondary hip replacement surgery would be morbidly obese, meaning their body mass index would be equal to or exceed 40. Moreover, in the event body mass is a risk factor for osteoarthritis, we anticipated this sub group would include individuals younger than 65 years of age, and that a fair proportion of these cases would be found to experience severe complications, protracted hospital stays, and prevailing comorbid health conditions, regardless of age. We anticipated that the research in this area on the whole would reveal that morbidly obese hip osteoarthritis cases may be at high risk for complications after surgery, despite efforts to improve their condition.
Materials and methods
Body mass indices (BMIs) calculatedretrospectively from available height and weight data of a sample of 1000 cases of hip osteoarthritis requiring unilateral or bilateral hip replacement, as well as revision surgery were examined. In addition to demographic data, the presence and type ofaccompanying chronic health conditions, and reasons for hospitalization noted on the chart, the body mass indices of the cohort were categorized into 4 broad categories: underweight (BMI <than 20kg.m-2), normal weight (BMI 20-24.9kg.m-2), overweight (BMI 25-29kg.m-2), and obese (>29kg.m-2) categories. Grade 1 obesity was categorized as having a BMI 30-35, grade II obesity cases has BMIs 36-39, and morbid obesity or obese grade III was denoted as a BMI of 40kg.m-2 or greater. These data were systematically entered into SPSS version 17.0 files to generate descriptive data, and where data were amenable to quantitative analysis, an a priori significance level of 0.05 was adopted. Excluded were cases with rheumatoid arthritis and hip fractures.
Results
The mean age of the sample of 997 cases with complete date was 65.5 ±12.98 years (range 23-94) and the majority (57%) were women. Calculations of body mass index showed most or 67% were overweight, on average. There were 40 excessively or morbidly obese cases, with body mass indices ranging from 40-68, and of these cases,75% were 65 years of age or younger, and 22 were females and 18 were males.Among those in the excessively obese or morbidly obese category (BMI > 40kg.m-2), 19% had diabetes compared to 11% among those in the healthy weight category, and 19/40 or approximately 50% of theseexcessively obese cases had comorbid hypertension histories (p < 0.01) and the mode for numbers of comorbid diseases was 2. Among the 35 cases who were categorized as being underweight, 5 or 14% had cardiovascular disease, 2 or approximately 6% had high blood pressure, and none had a diabetes or depression diagnosis and the mode for numbers of comorbid diseases was 1(Tables 1 and 2).
|
Variable
|
Entire Cohort
N=997
|
|
Age (years), mean ± SD
|
65.5 ± 12.98, range 23-94
|
|
Age range, (n,%)
<65 yrs
>65 yrs
|
391(39.2)
599(60)
|
|
Sex
Female
Male
|
568(57)
424 (48)
|
|
BMI (kg.m-2), mean ± SD
|
27.6±5.7, range 15-68
|
|
Type of Surgery, (n,%)
Unilateral surgery
Bilateral Surgery
Revision Surgery
Complications
|
770(77.2)
54(5.4)
122(12.2)
48(4.8)
|
Table 1.Characteristics of cohort of hip osteoarthritis patients requiring primary or secondary surgery (n=997)
BMI=body mass index
|
BMI Category
|
|
|
Underwt
|
Normal
|
Overweight
|
Obesity
|
|
|
I
|
II
|
III
|
|
Variable
|
< 20
|
20-24.9
|
25-29.9
|
30-35
|
36-39
|
40+
|
|
Number of patients (n,%)
|
35(3.5)
|
294(29.5)
|
382(38.3)
|
194(19.5)
|
68(8.8)
|
40(4.0)
|
|
Mean BMI kg.m-2
|
18.8 ± 3.9
|
22.3 ±1.8
|
26.9+1.6
|
31.4+1.6
|
36.3+1.3
|
44+5.7
|
|
Number with Diabetes
|
0
|
4
|
21
|
9
|
4
|
9
|
|
Number with CVD
|
5
|
62
|
90
|
35
|
15
|
10
|
|
HBP
|
2
|
71
|
136
|
68
|
35
|
19
|
|
Depression
|
0
|
19
|
23
|
4
|
7
|
3
|
|
Revision surgery
|
1(0.8)
|
43(35.2)
|
44(36.1)
|
24(19.7)
|
7(5.7)
|
3(2.5)
|
|
Complications –within type
-within wtcateg
|
1(2.1)
6.3%
|
9(18.8)
3.1%
|
17(35.4)
4.5%
|
13(27.1)
5.7%
|
4(8.3)
5.9%
|
4(8.3)
10%
|
Table 2. Depiction of various patient atributes across body mass categories showing distinct differences between underweight and morbidly obese sample on selected variables (N=997).
BMI-body mass index; CVD=cardiovascular disease; HBP=hypertension; Underwt-underweight
As outlined in Table 2,among thecohort of patients undergoing primary or secondary surgeries, slightly more cases were excessively obese than underweight, and those who were morbidly obese were more likely to be hospitalized forserious complications following prior hip surgery than those who were underweight, as well as those in any other weight category.Table 3 depicts the overall health status and functional ability and past history of 12 morbidly obese cases and shows that many had prior hip osteoarthritis or other joint problems, and multiple comorbid conditions, even though they were all deemed relatively young adults.Findings from thetwo superobese cases shown in Table 4are generally consistent in showing the increased risk of sub optimal outcomes in the short and long term among the severely obese hip osteoarthritis surgical candidate.Table 5 reveals consistent evidence that caution is advised when patients are morbidly obese and recommended for hip replacement surgery.
|
ID
|
Age
|
Gender
|
Comorbid status
|
BMI
|
>Ideal wt
|
# blocks
|
Prior Hx
|
|
1
|
62
|
F
|
HBP, MI, Hypothy
|
50
|
246
|
3
|
Yes
|
|
2
|
50
|
F
|
Hypothy, Depress, Asthma
|
40
|
188
|
2
|
No
|
|
3
|
65
|
F
|
HBP, MVP, Hypothy
|
42
|
208
|
2
|
No
|
|
4
|
53
|
F
|
HBP, Asthma
|
43
|
208
|
0
|
Yes
|
|
5
|
64
|
F
|
Diabetes, Depress, Asthma
|
44
|
-
|
0
|
No
|
|
6
|
65
|
M
|
Atrial fib, Prediab
|
40
|
166
|
3
|
Yes
|
|
7
|
57
|
M
|
Prediab
|
41
|
-
|
1
|
Yes
|
|
8
|
48
|
M
|
COPD, HBP
|
40
|
169
|
10
|
Yes
|
|
9
|
50
|
M
|
Diabetes, HBP
|
58
|
257
|
0
|
Yes
|
|
10
|
54
|
M
|
Diabetes, Atrial fib
|
40
|
166
|
0
|
Yes
|
|
11
|
51
|
M
|
HBP, Depress
|
45
|
186
|
1
|
No
|
|
12
|
56
|
M
|
Nil
|
44
|
191
|
.25
|
No
|
Table 3. Table depicting extent of disability observed among selected relatively young morbidly obese adults with hip osteoarthritis undergoing primary or secondary surgeries
# blocks=number blocks able to walk prior to surgery; Atrial fib-atrial fibrillation; COPD=chronic obstructive airways disease; HBP=high blood pressure; Hypoth=hypothyroidism; Hx=history; Depress=depression; Prediab=prediabetes
Discussion
Although the relationship between overweight and hip joint osteoarthritis is not definitive, results of this present analysis suggest overweight, and especially being morbidly obese is an important element observed among cases with disabling hip osteoarthritis, especially younger cases. This subgroup is also at risk for severe complications such as infection.
This is consistent with Changulani et al. [8] who found those in the morbidly obese range were almost 10 years younger on average than those in the normal weight category, and those with higher body weights were more likely to experience adverse surgical outcomes than those who were not. This also accords with Tai et al. [9] and with Guetner et al.[10]. As in Guetner et al.’sstudy, it appears younger adults, especially those who suffer from morbid obesity may be quite prone to developing hip joint osteoarthritis in both hips, as well as other disabling health conditions. They may also require early hip joint replacement surgery, while incurring an increased risk of poor surgical outcomes, and the onset of comorbid diseases that can prevent optimal outcomes.
While Grotle et al. [2] found no association between body mass and hip osteoarthritis,obesity, an independent predictor of disability [12-14] and pain [16,17], can undoubtedly place excess biomechanicalstress on the hip joint. It can also increase chances of adopting a sedentary lifestyle, and hencenot unsurprisingly, greater body weight and body mass index during early and middle adulthood[15].
Since being overweight could render individuals of any age subject to abnormal hip jointloading forces, hip joint destruction may beespecially exaggerated in the morbidly obeseindividual. Moreover, associated high rates ofpain, as well as joint destruction and posturalchanges inthose who are excessively obese can be expected to impact the pathogenesis of hipjointosteoarthritis both before and after surgery more profoundly than non-obese situations [18,19]. Alternately, the constellation of obesity, immobility and pain can independently raise therisk for hip joint osteoarthritis, and its disability [21-31].
Morbid obesity is an enormous health care problem, and should not be ignored as an important factor impacting the onset and rate of hip osteoarthritis disability and its severity, as implied in Table 4-where the relatively young hip surgery candidates had had many prior years of joint dysfunction, and very poor outcomes at five days post-surgery compared to standard outcomes for most uncomplicated procedures among healthy or normal weight subjects.Since ample research shows obesity is a preventable situation related to energy balance, the importance of food intake and nutrition, and restoring functional mobility cannot be overlooked in this regard, in our view, even if this was not the view of McAlden et al. [31].
|
ID
|
Gender Age
|
BMI # Meds
|
# Med Cond
|
# Yrs Impaired
|
Post-op hosp status after 5 days
|
|
1
|
F 62
|
50 >3
|
3
|
21
|
Ambulates only with assistance
|
|
2
|
M 50
|
58 >3
|
2
|
15
|
Stood with walker-no walking
|
Table 4. Selected attributes of two hip osteoarthritis surgery cases classified as being super obese (BMI >50) exemplifying extent of disability despite being younger than 65 years of age
BMI=body mass index; #meds=number medications; #med cond=number medical conditions; # yrs impaired=number years impaired
Consequently, although patients with hip osteoarthritis may routinely receive physical therapy for limited periods before and after surgery, more emphasis on the role good nutrition can have on the joint, and on reducing inflammation, while reducing the ratio of fat to muscle should be stressed, along with possibly routinely extending the pre operative period as well as the intensity and duration of post operative therapy.
Helping to prevent excess obesity in the formative years, and ensuring those affected are monitored for any emerging pain and disability is recommended as well. Other possible recommendations for reducing the adverse results shown in Tables 4 and 5, are the possible inclusion of nutrition educators in the team treating the hip osteoarthritis patient, and the design of foods that reduce diabetic complications, as well as vascular complications. Helping this sub group to reduce any proclivity towards depression is also indicated. As well, apprising the morbidly obese hip osteoarthritis surgical candidate of the increased risk of poor surgical outcomes at the outset, and encouraging weight loss is recommended.
|
Authors
|
Study procedures and Sample
|
Results
|
Conclusion
|
|
Arsoyet al. [32]
|
The results of total hip arthroplasty in 42 primary total hip arthroplasties in super-obese patients (BMI ≥ 50) were reviewed.
|
Twenty-four of the THAshad at least one complication. At least one major complication occurred in 11 of
the THAs and at least one minor complication in 14 THAs
|
Caution should be used when
proceeding with primary total hip arthroplasty with a BMI greater than 50.
|
|
Chee et al. [5]
|
The authors analyzed outcomes of 55 consecutive total hip replacements performed on 53 morbidly obese patients with osteoarthritis with a matched group of 55 total hip replacements in 53 non-obese patients.
|
Survival at five years was 90.9% for morbidly obese and 100% for non-obese patients
Harris Hip and the Short-form 36 scores were significantly better in non-obese group (p < 0.001)
The morbidly obese patients had higher complication rates, which included dislocation, superficial and deep infection
|
Morbidly obese patients should be advised to lose weight before undergoing total hip replacement, and counseled regarding the risk of complications.
|
|
Elson et al. [19]
|
This evaluation was performed to determine if morbid obesity
(BMI ≥35 kg/m(2)) is a contributing risk factor to cup malpositioning.
|
There was a significant correlation between morbid obesity with
respect to underanteversion; using multivariate analysis, there was a trend
toward a combined underanteversion/overabduction of the acetabular cup.
|
Of all variables considered, high BMI was the most significant risk factor leading to malpositioning.
|
|
Houdeket al. [6]
|
Studied the effect of morbid obesity as a risk factor for failure of two-stage revision total hip arthroplasty using medical records of 653 cases treated for periprosthetic joint infection over a 20 year period
|
Compared with nonobese cases, morbidly obese cases had higher re infection, revision, and reoperation rates,
|
Morbidly obese patients have increased risk of severe post-operative complications after revision total hip arthroplasty than nonobese patients
|
|
Jamesenet al. [22]
|
Examined one-year incidence of periprosthetic joint infections among 7181 primary hip and knee replacements.
|
The infection rate for those with normal body mass indices was 0.37$, while the rate for those who were morbidly obese was 4.66%
|
Morbid obesity increases the risk for periprosthetic infection following primary hip or knee replacement
|
|
Issaet al. [33]
|
Assessed the outcomes of primary total hip arthroplasty in super-obese patients compared to a cohort who had a normal body mass index.
|
The super-obese patients had significantly lower mean Harris hip scores (84 vs 91 points) and higher complication rate at
final follow-up.
|
Patients may benefit from a discussion with their orthopaedic surgeons to develop
realistic expectations from the outcomes of their arthroplasty procedure.
|
|
Pulido et al. [34]
|
Reviewed a database of 9245 patients undergoing hip or knee arthroplasty between January 2001 and April 2006
|
Prosthetic infections developed in 63 patients, and among the independent predictors was morbid obesity
|
Morbid obesity and other factors may predispose patients to periprosthetic joint infection
|
|
Puloset al. [35]
|
Retrospectively examined 309 consecutive revisions of total hip arthroplasty from 2005-2009, and compared subgroup with body mass index greater than 35 to those with body mass indices below 35
|
At 36 months, there was a higher rate of re-operation in the obese group, especially for infection
|
Patients should be aware of their increased risk for post-surgical complications after total hip arthroplasty if they are obese
|
|
Rajgopalet al. [37]
|
Examined the complications and outcomes of total
hip replacement (THR) in super-obese patients (body mass index (BMI) > 50
kg/m(2)) compared with class I obese (BMI 30 to 34.9 kg/m(2)) and normal-weight
patients (BMI 18.5 to 24.9 kg/m(2)), as defined by the World Health Organization.
|
Super-obese patients experienced significantly
longer hospital stays and higher rates of major complications and readmissions
than normal-weight and class I obese patients.
|
Despite improved function and satisfaction, morbidly obese group experience a significant
increase in length of hospital stay and major complication and readmission rates.
|
|
Schwarzkopf et al.[38]
|
Conducted a retrospective study to determine the difference in
outcomes among the super-obese
|
When categorized according to body mass index, the overall complication rate was higher for patients with BMI > 45
Super-obese patients had an increased odds of developing
In hospital complications
Length of stay was increased by 13.8% for each 5-U
increase in BMI above 45
|
There is a n increased risk of incurring complications
among the super-obese, and this increases with BMIs
greater than 45
|
|
|
|
|
|
Table 5. Studies examining impact of morbid obesity on total hip replacement surgery outcomes
Conclusion
Having a high body mass appears more characteristic than not of individuals hospitalized for purposes of total hip replacement, revision surgery, or severe complications from prior surgery. Whether this is a consequence of the disease, rather than a cause or risk factor it is important to consider:
- A small percentage of end stage hip osteoarthritis cases are morbidly obese.
- Those with excessively high body mass indices are younger on average than those 65 years of age.
- Excessively obese cases with BMIs> 40 were more likely to have high rates of diabetes and blood pressure than those of normal weight.
- Being excessively obese is related to the presence of a severe surgical complication.
Hence despite the limitations ofthis cross-sectional study for pinpointing causation, thispresent overviewimplies efforts to minimizethe onset and progression of obesity across the lifespanmay prove highly beneficial,despite lack of consensus of a distinct correlation of these factors [25].Moreover, those who are excessively obese and undergo surgery might be counseled about their situation and encouraged to lose weight prior to this intervention. Careful rehabilitation that takes into account the presence of comorbid conditions, may foster better overall long-term results. Research to examine this sub-group as a separate issue will potentially yield important understandings that can be applied to harm reduction efforts, as well as reparative efforts.
2021 Copyright OAT. All rights reserv
References
- Murphy LB, Helmick CG, Schwartz TA, Renner JB, Tudor G, et al. (2010) One in four people may develop symptomatic hip osteoarthritis in his or her lifetime. Osteoarthritis Cartilage 18: 1372-1379.[Crossref]
- Grotle M, Hagen KB, Natvig B, Dahl FA, Kvien TK (2008) Obesity and osteoarthritis in knee, hip and/or hand: an epidemiological study in the general population with 10 years follow-up. BMC MusculoskeletDisord 9: 132.[Crossref]
- Holliday KL, McWilliams DF, Maciewicz RA, Muir KR, Zhang W, et al. (2011) Lifetime body mass index, other anthropometric measures of obesity and risk of knee or hip osteoarthritis in the GOAL case-control study. Osteoarthritis Cartilage 19: 37-43.[Crossref]
- Kessler S, Käfer W (2007) Overweight and obesity: two predictors for worse early outcome in total hip replacement? Obesity (Silver Spring) 15: 2840-2845.[Crossref]
- Chee YH, Teoh KH, Sabnis BM, Ballantyne JA, Brenkel IJ (2010) Total hip replacement in morbidly obese patients with osteoarthritis: results of a prospectively matched study. J Bone Joint Surg Br92: 1066-1071.[Crossref]
- Houdek MT, Wagner ER, Watts CD, Osmon DR,Hanssen AD, et al. (2015) Morbid obesity: a significant risk factor for failure of two-stage revision total hip arthroplasty for infection. J Bone Joint Surg Am 97: 326-332.[Crossref]
- Lübbeke A, Stern R, Garavaglia G, Zurcher L, Hoffmeyer P (2007) Differences in outcomes of obese women and men undergoing primary total hip arthroplasty. Arthritis Rheum 57: 327-334.[Crossref]
- Changulani M, Kalairajah Y, Peel T, Field RE (2008) The relationship between obesity and the age at which hip and knee replacement is undertaken. J Bone Joint Surg Br 90: 360-363.[Crossref]
- Tai SM, Imbuldeniya AM, Munir S, Walter WL, Walter WK1, et al. (2014) The effect of obesity on the clinical, functional and radiological outcome of cementless total hip replacement: a case-matched study with a minimum 10-year follow-up. J Arthroplasty29: 1758-1762.[Crossref]
- Guenther D, Schmidl S, Klatte TO, Widhalm HK, Omar M, et al. (2015) Overweight and obesity in hip and knee arthroplasty: Evaluation of 6078 cases. World J Orthop6: 137-144.[Crossref]
- Liu B, Balkwill A, Banks E, Cooper C, Green J, et al. (2007) Relationship of height, weight and body mass index to the risk of hip and knee replacements in middle-aged women. Rheumatology (Oxford) 46: 861-867.[Crossref]
- Jacobsen S, Sonne-Holm S (2005) Increased body mass index is a predisposition for treatment by total hip replacement. IntOrthop 29: 229-234.[Crossref]
- Vinciguerra C, Gueguen A, Revel M, Heuleu JN, Amor B, et al. (1995) Predictors of the need for total hip replacement in patients with osteoarthritis of the hip. Rev RhumEngl Ed 62: 563-570.[Crossref]
- Wallace G, Judge A, Prieto-Alhambra D, de Vries F, Arden NK, et al. (2014) The effect of body mass index on the risk of post-operative complications during the 6 months following total hip replacement or total knee replacement surgery. Osteoarthritis Cartilage22: 918-927. [Crossref]
- Wang Y, Wluka AE, Simpson JA, Giles GG, Graves SE, et al. (2013) Body weight at early and middle adulthood, weight gain and persistent overweight from early adulthood are predictors of the risk of total knee and hip replacement for osteoarthritis. Rheumatology (Oxford) 52: 1033-1041.[Crossref]
- Singh JA, Lewallen D (2009) Age, gender, obesity, and depression are associated with patient-related pain and function outcome after revision total hip arthroplasty. ClinRheumatol 28: 1419-1430.[Crossref]
- Iannone F, Lapadula G (2010) Obesity and inflammation--targets for OA therapy. Curr Drug Targets 11: 586-598.[Crossref]
- Fabris de Souza SA, Faintuch J, Valezi AC, Sant'Anna AF, Gama-Rodrigues JJ, et al. (2005) Postural changes in morbidly obese patients. ObesSurg15: 1013-1016.[Crossref]
- Elson LC, Barr CJ, Chandran SE, Hansen VJ, Malchau H, et al. (2013) Are morbidly obese patients undergoing total hip arthroplasty at an increased risk for component malpositioning? J Arthroplasty 28: 41-44.[Crossref]
- Magliano M (2008) Obesity and arthritis. Menopause Int 14: 149-154.[Crossref]
- Cimmino MA, Scarpa R, Caporali R, Parazzini F, Zaninelli A, et al. (2013) Body mass and osteoarthritic pain: results from a study in general practice. ClinExpRheumatol 31: 843-849.[Crossref]
- Jameson SS, Mason JM, Baker PN, Elson DW, Deehan DJ, et al. (2014) The impact of body mass index on patient reported outcome measures (PROMs) and complications following primary hip arthroplasty. J Arthroplasty 29: 1889-1898.[Crossref]
- Lübbeke A1, Moons KG, Garavaglia G, Hoffmeyer P (2008) Outcomes of obese and nonobese patients undergoing revision total hip arthroplasty. Arthritis Rheum 59: 738-745.[Crossref]
- MaraditKremers H, Visscher SL, Kremers WK, Naessens JM, Lewallen DG (2014) Obesity increases length of stay and direct medical costs in total hip arthroplasty. ClinOrthopRelat Res 472: 1232-1239.[Crossref]
- Jones DG (2009) Articular cartilage degeneration: etiologic association with obesity. Ochsner J 9: 137-139.[Crossref]
- Stürmer T, Günther KP, Brenner H (2000) Obesity, overweight and patterns of osteoarthritis: the Ulm Osteoarthritis Study. J ClinEpidemiol 53: 307-313.[Crossref]
- Ackerman IN, Osborne RH (2012) Obesity and increased burden of hip and knee joint disease in Australia: results from a national survey. BMC MusculoskeletDisord13: 254.[Crossref]
- Jiang L, Rong J, Wang Y, Hu F, Bao C, et al. (2011) The relationship between body mass index and hip osteoarthritis: a systematic review and meta-analysis. Joint Bone Spine 78: 150-155.[Crossref]
- Andrew JG, Palan J, Kurup HV, Gibson P, Murray DW, et al. (2008) Obesity in total hip replacement. J Bone Joint Surg Br 90: 424-429.[Crossref]
- Teichtahl AJ, Wang Y, Smith S, Wluka AE, et al. (2015) Early cartilage abnormalities at the hip are associated with obesity and body composition measures - a 3.0T MRI community-based study. Arthritis Res Ther 17: 107.[Crossref]
- McCalden RW, Charron KD, MacDonald SJ, Bourne RB, Naudie DD (2011) Does morbid obesity affect the outcome of total hip replacement?: an analysis of 3290 THRs. J Bone Joint Surg Br 93: 321-325.[Crossref]
- Arsoy D, Woodcock JA, Lewallen DG, Trousdale RT (2014) Outcomes and complications following total hip arthroplasty in the super-obese patient, BMI > 50. J Arthroplasty 29: 1899-1905.[Crossref]
- Issa K, Wohl H, Naziri Q, McDermott JD, Cherian JJ, et al. (2013) Early results of total hip arthroplasty in the super-obese patients. J Long Term Eff Med Implants 23: 309-313.[Crossref]
- Pulido L, Ghanem E, Joshi A, Purtill JJ, Parvizi J (2008) Periprosthetic joint infection: the incidence, timing, and predisposing factors. ClinOrthopRelat Res 466: 1710-1715.[Crossref]
- Pulos N, McGraw MH, Courtney PM, Lee GC (2014) Revision THA in obese patients is associated with high re-operation rates at short-term follow-up. J Arthroplasty 29: 209-213.[Crossref]
- Mednick RE, Alvi HM, Krishnan V, Lovecchio F1, Manning DW1 (2014) Factors Affecting Readmission Rates Following Primary Total Hip Arthroplasty.J Bone Joint Surg Am 96: 1201-1209.[Crossref]
- Rajgopal R, Martin R, Howard JL, Somerville L, MacDonald SJ, et al. (2013) Outcomes and complications of total hip replacement in super-obese patients. Bone Joint J 95-95B: 758-63.[Crossref]
- Schwarzkopf R, Thompson SL, Adwar SJ, Liublinska V, Slover JD (2012) Postoperative complication rates in the "super-obese" hip and knee arthroplasty population. J Arthroplasty 27: 397-401.[Crossref]
