Obesity: Effect on Total Joint Replacement Patients

Obesity: Effect on Total Joint Replacement Patients The critical factor driving the growth in worldwide demand for joint replacement is obesity Kumar Anjan Contents (Jump to) Abstract: 1. Introduction 2. Obesity – How can we define it? 3. Surgical Risk: 4. Obesity and Implant Failure 5. Conclusion 6. Bibliography Abstract: During early days, obese individuals were often suggested to lose weight before undergoing total joint replacement (TJR). It was common observation amongst surgeons and doctors that morbidity rate amongst obese individuals were significantly high as compared to that of non-obese subjects. In addition, there was significant increase in the physical and technical labour of operating overweight individuals. This resulted in time saving and managing long queue of patients. Recently, scientific reports with positive results reflected that there is only negligible effect of obesity on TJR. However, recently in the UK several health care authorities proposed that there would not be any financial support provided to the individuals whose BMI exceeds 30 kg/m2. The primary reason behind the decision is the reduction in health care budget. In olden days, TJR was a procedure considered for those who were more than 65 years of age. However, this trend is significantly changing. According to Dr. A yeres (MD, Chair in Orthopaedics, and director of the Musculoskeletal Centre of Excellence at UMass Medical School), with an increased rate of obesity amongst individuals under the age of 65 is acting as a driving force towards TJR. Therefore, in this case report I have discussed about obesity and its effect on TJR.   1. Introduction: Total joint replacement (TJR) is globally acknowledged especially due to the revolution in the quality of life for those individuals suffering from osteoarthritis or similar health problems (Garellick et al, 1998). Moreover, in modern medicine TJR has proved its effectiveness as one of the most successful interventions. There are also several high demo graphs recorded towards the improvement of the quality of life, which surpasses coronary artery bypass as well as renal transplants (Williams A, 1985). In elderly population, TJR’s especially knee anthroplasty has shown to be most effective technology resulting towards better life quality. Study conducted among a population cohort of over 65 subjects who had TJR shows that they are leading a healthier life (UK population Census, 2001). Total joint replacement has definitely bought a revolution in modern health care system. However, there are certain implications that concern the public. One of the most critical limitations is the budgetary control which enforced by the competitive claim from the other intensive medical care system. Furthermore, as these treatments are not actually cost effective; therefore, it raises questions for the individuals undergoing a replacement as well as the government bodies who support the funding (Templeton, S.K. 2005). Recently, East Suffolk health trust in the U.K. decided to prioritize their patients undergoing TJR according to their weight and various other factors resulting in obesity. According to the top management of the trust, individuals who are overweight or obese are at an increased risk towards the efficacy of the surgery. This decision has definitely stirred controversy among the community undergoing TJR (Finer N, 2005). However, according to some valued sources, there i s no evidence that age, obesity or gender affects the functional outcome of the surgery (Templeton, S. K. 2005). Therefore, there is huge controversy surrounding towards the potential implications of obesity on TJR. Orthopaedic studies suggest that obesity leads towards degenerative changes in joints and leads towards complications and functional risk during post-surgery phase (Rockville, 2003). As there is no standard definition for obesity, it rather becomes very difficult to understand its actual meaning. However, several health care professionals recommend that problem in mobilisation and functional outcome is not visualised until an individual’s (BMI) exceeds 40 kg/m2 (Nammi et al, 2004). Various evidences conclude that obesity is the driving force towards development of osteoarthritis particularly in individuals with high BMI in an early age (DoH, 2001). In some rare scenarios, bariatic surgery is performed on the individuals before TJR. This is mainly due to bring their weight down to an acceptable score. 2. Obesity – How can we define it? Over several years, different authors described obesity in a different way. Obesity does not have an actual standard definition. However, the most common scientific way to describe obesity is based on the Body Mass Index (BMI) (Fig: 1) (Lawrence, 1998). BMI is also known as Quetelet Mass Index (QI) and is generally described as the ratio of the square of the height measured in meters (mt) to the weight in kilograms (kg) (Taylor, 1998). QI relates the body fat percentage and is one of the most preferred methods for the assessment of the potential health risk related with the overweight or obesity. Recently, authors started using the term â€Å"New World Syndrome† for obesity as its prevalence is dramatically increasing in the Europe as well as in the United States (USA). A shocking figure was projected when a recent survey was conducted by the Department of Health in the UK. According to the survey, prevalence in obesity has increased from 15% since 1995 to 21% in 2001 (Webb et al, 2004). Fig: 1 BMI Chart the ratio of the square of the height measured in meters (mt) to the weight in kilograms (kg). In the US, obesity has reached in an epidemic proportion. Considering the BMI of an individual, more than half of the adult population in the US are classified as overweight. According to a separate survey conducted in the US amongst 65-74 year age group, 66% were referred to as obese or overweight. Therefore, we can visualise the prevalence of obesity coinciding with the peak age during which most of the individual requires TJR (US Dept. of Health and Human Services, 2003). In the UK, the data shows similar outcomes to that of the US. Obesity amongst males in the UK has increased from 6% in 1980 to 22% in 2002 whereas in females, 8% 23% (DhO, 2001). According to the World Health Organisation (WHO), there is an increase in obesity between 10% 40% in last 10 years. WHO also claims that there are approximately 200 million obese adults around the globe and 18 million children under age five are classified as overweight. Moreover, by 2000 this data significantly increased to over 300 m illion. Osteoarthritis (OA) is a group of mechanical abnormalities, which involves in the degradation of joints, articular cartilage. It generally affects approximately 20 million individuals in the US. It causes substantial morbidity leading to disability in the later stages. This disease is more common amongst elderly population. However, recently it was observed that adult age group between 60-65 years of age are getting prone to this disease. According to few scientific sources, the main reason for OA amongst younger generation is obesity. Various scientific reports documents that in the US more than 200,000 knee and hip replacements are performed each year and 35% are young individuals under the age of 65 (Dho, 2001; US Dept. of Health and Human Services, 2003). Obesity is one of the most significant risk factors contributing towards osteoarthritis. Therefore, with an increase in obesity, there is a high probability of developing osteoarthritis. Moreover, this leads towards an increase prevalence of TJR (Felson et al, 2000). As we know that, there is a constant increase among obese patients undergoing TJR. Therefore, several researches links obesity with the TJR as well as the complications associated with the same. According to a joint study performed by a group of scientists and surgeons, it was found that there is an increase in complication rate in obese patients as compared to individuals with normal BMI (Olivera et al, 1999; Sahyoun et al, 1999). In addition, the operative duration significantly increases in obese subjects. However, factors like physical stress and injury to health care professional remains undiscovered. As already mentioned, it has been well established that there is a positive link that connects TJR and obesity. Whil st examining, individuals with high BMI are in an exponential increase for TJR over next few decades. According to several health care professionals, there is often a challenging situation during pre/post surgery in obese individuals. Moreover, there is a high risk of blood loss and blood transfusion. It has also been highlighted that nerve injury is common amongst obese patients as compared to the healthy individuals (non-obese) during TJR (Mantilla et al, 2003). 3. Surgical Risk: In the previous section, it was discussed that East Suffolk Health Trust in the UK prioritised their patients, which resulted in a huge controversy. According to public and human right activists, their decision was biased towards the individuals with higher BMI. The main reason behind the decision was increased risk and the cost involved in performing TJR amongst obese/overweight individuals. Supporting the decision of East Suffolk Health Trust, â€Å"Ipswich Protocol† was followed. According to this protocol, orthopaedic surgeons and health care personals were advised that patients/individuals found with BMI>30 should be barred towards the access of TJR/anthroplasty (Amen et al, 2006). Winiarsky’s group performed a research on a population cohort with BMI>40 undergoing TJR. The result showed that 22% of the subjects suffered from wound complication, 10% individuals developed infection and 8% of the subjects suffered from ligament damage. When these result was compared with the wild type (normal population), it was seen that only 2% non-obese subjects developed wound complication, 0.6% suffered from infection and surprisingly there were non with ligament damage. Later, same group of individuals were studied after five years and significant post surgical differences were noticed in obese subjects as compared to the normal (non-obese) individuals. Therefore, we can conclude from the above study that obese patients have high risk during pre and post surgery (Vasqez et al, 2003). However, in Toronto, a random survey amongst 24231-population cohort showed that after 2-7 years of surgery there was a high level of patient satisfaction with reference to pain and func tion. In addition, there was no negative impact on outcome that co-related with subject’s age or obesity (Heisel et al, 2005). In Los Angeles California, Miric et al studied several factors leading towards TJR complexity. Research was performed amongst 406 subjects undergoing total knee anthroplasty (TKA). According to the researchers, it was observed that there was a significant co-relation between BMI and subject’s cardiac history. Interestingly, patients with diabetes mellitus have had an increase stay in hospital as compared to the healthy (non-diabetic) patients. Therefore, the study concluded that there was not a significant difference amongst heavier patients as compared to those with normal BMI. In addition, the cut offs of BMI dividing overweight and obesity did not accurately divide patients into high/low risk categories (Foran et al, 2004). In Scotland, research was performed amongst group of 283 TKA patients between 1995 and 1999 consisting of obese and non-obese subjects. Researchers concluded that there was no significant difference in complication rates (Peersman et al, 2001). In a similar study in Baltimore Maryland, evaluation outcome of TKA in 68 obese subjects showed that after five years of surgery there was no significant difference amongst obese and non-obese subjects. However, surprisingly after 7 years of surgery obese patients had a higher â€Å"implant failure† rate as compared to non-obese subjects. It was also noted that 12.3% of the obese patients had to go for a re-operation due to implant failure. In addition, deep vein thrombosis was only noticed in obese subjects. Pritchett and Bortel described that obese patients had greater blood loss and needed blood transfusion as well as longer operative time. Peersman supported the view saying that the increase in the infection rate in obese patients w as due to the prolonged operative duration (Prichett and Bortel, 1991). 4. Obesity and Implant Failure As described in the previous section, in Baltimore, there was no evidence of either complication or mortality amongst obese patients after five years of surgery. However, the same group individuals suffered an â€Å"Implant Failure† after seven years of TJR. Various researches were conducted and scientists concluded that younger patients (age 65). Simulation of metal-onpolyethylene arthroplasty model under laboratory conditions showed that the principle cause of the device failure was due to increased wear rates when greater load was applied. Hence, it was proved that younger subjects due to their daily life routine were applying more force on the implant as compared to elder population cohort (Barbour et al, 1995; McKellop et al, 1995). Moreover, subjects who were able to reduce weight in seven years were living a healthier life as compared to other subjects. Therefore, we can conclude that obesity also potentially affects the device failure in long run. 5. Conclusion Recently, obesity and TJR has pulled the interest of several scientists, health care personals and even the government. Various government officials and trust group supporting financial aid are still under the impression that obesity leads to TJR. However, there is neither significant evidence nor sufficient clinical results to support their view. TJR surgery is a reliable procedure to offer sustainable pain relief and provide healthier life style regardless individual’s BMI. However, we cannot ignore the fact that obese individuals require special care in terms of patient handling, surgical exposure etc. In addition, obese subject are also at a high risk in wound healing, infection and longer duration of operative duration. It is also clinically proven that higher activity level leads towards device failure. As mentioned earlier, due to physical work restriction after TJR high probability lies towards increasing BMI. Therefore, it is recommended that individual’s shoul d attend weight loss programme before undergoing TJR. 6. Bibliography Amin AK, Clayton RA, Patton JT, Gaston M, Cook RE, Brenkle IJ. Total knee replacement in Morbidly Obese Patients. J Bone Jt Surg 2006;88(10-B):1321–6. Barbour PSM, Barton DC, Fisher J. The influence of contact stress on the wear of UHMWPE for hip replacements. Wear 1995;181–183:250–7. DoH Health Surveys, 1980, 1995, 2001 — Department of Health Publication, HMSO. Finer N. 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