Total knee arthroplasty without patellar resurfacing in active and overweight patients

The Patellar Resurfacing in Total Knee Prosthesis: Indications for Bone Stock and Patellar Morphology

The patellar resurfacing is still a controversial and unresolved problem. The choice to use the patellar resurfacing in the total knee prosthesis (TKP) is decided by the surgeon's experience; he analyzes the thickness, the shape, consumption of the surface and he chooses the use of patellar resurfacing or to limit itself to cheiloplasty, denervation, or often to the release of the lateral wing ligament. He also assesses the metabolic state of the bone linked to Osteoporosis and the potential fragility of the joint and kneecap in particular. Bone loss after total knee arthroplasty (TKP) may lead to periprosthetic fractures that are associated with significant costs (morbidity, economic, etc.) and pose a challenge to operative fixation. The literature doesn't express a definitive judgment on the two options, since the results can be overlapped on average. Each option has advantages and disadvantages to be considered in the overall balance of the patellar operation. In reality, however, this technical choice requires more consolidated decision-making criteria so as to minimize the incidence of post-surgical femoral-patellar pain syndrome, the second cause of failure, which frequently leads to revision of the implant. The balance between experience and evidence can be a compromise in the choice of surgery. The experience documented in the literature must identify the parameters capable of constructing an algorithm aimed not only at the secondary resurfacing rate, but at the overall clinical evaluation. This has implications also for the rehabilitation of these patients after surgery.

Review article: Outcome of total knee arthroplasty in obese patients

The MEDLINE database was searched using the key words: 'obesity' and 'knee arthroplasty'. 41 articles focused on the topic were reviewed; most studies were prospective case series (providing low-level evidence) and 3 were systematic reviews. 16 studies reported no adverse association between obesity and total knee arthroplasty (TKA) outcome, whereas 24 studies reported a poorer TKA outcome in obese patients. In the 3 systematic reviews, obesity was reported to adversely affect the outcome, the rate of complications, implant survival, and the cost of TKA.

The Influence of Obesity on the Outcome of TKR: Can the Impact of Obesity be justified from the Viewpoint of the Overall Health Care System?

BACKGROUND

There is controversy in the literature regarding the justification of performing total knee replacement (TKR) in obese patients in view of their increased risk of poor outcomes and how those poorer outcomes impact the health care system overall.

QUESTIONS/PURPOSES

Is TKR justifiable in the obese patient? Can the negative impact of continuing to perform TKR in the obese be quantified?

METHODS

A Cochrane Library, PubMed (MEDLINE), and Google Scholar search related to the justification of TKR in the obese patient and its impact on the health care system was analyzed. The main criteria for selection were that the articles were focused in the aforementioned questions.

RESULTS

Two thousand one hundred seventy-three articles were found, but only 50 were selected and reviewed because they were focused on the questions of this paper. Although some articles (with low grade of evidence) did not find that obesity adversely affected the outcome of TKR, most of them found that obesity adversely affected the results of TKR. Regarding complications rates and survival rates, obesity has shown to have a negative influence on outcome after TKR. The improvements in patient-reported outcome measures, however, were similar irrespective of body mass index. Regarding the impact of TKR in obese patients, an extra cost of US$3,050 has been reported per patient. Considering that 50% of the US population is obese and that 600,000 TKRs are implanted per year, the impact for the US health system could be as much as 915 million dollars (300,000 × 3,050).

CONCLUSION

TKR in obese patients may be justifiable because the functional improvements appear equivalent to those of patients with a lower BMI. However, in obese patients, the risk of complications is higher and the prosthetic survival is lower. Moreover, TKR in obese patients has a huge impact on the health system which should be considered.

Is patellar resurfacing superior than nonresurfacing in total knee arthroplasty? A meta-analysis of randomized trials

Conflicting results from abundant studies have made it unclear whether the patella should be resurfaced during total knee replacement. A meta-analysis was undertaken to pool the results of randomized controlled studies (RCTs) and to compare the outcomes and postoperative complications after total knee arthroplasty with patellar resurfacing or nonresurfacing. Sixteen RCTs including 3034 knees between 1966 and December 2009 were analyzed. Reoperation for patellofemoral problems was significantly more likely in the nonresurfacing group (P = 0.03). There was no difference between the two groups in terms of anterior knee pain rate, knee pain score, knee society score and knee function score. The results indicate that patellar resurfacing would reduce the risk of reoperation after total knee replacement, but it seems that the benefits are limited on other aspects, and the analysis of high-quality studies shows no advantage of resurfacing over nonresurfacoing group, even in the aspect of reoperation risk. More carefully and scientifically designed RCTs are beneficial and necessary to further prove the results.

Bilateral staged total knee arthroplasty in obese patients

INTRODUCTION

The purpose of this study was to compare the clinical and functional results and complications associated with staged bilateral total knee arthroplasty (TKA) performed 4-11 days apart during a single hospitalization in patients who were obese and patients who were not obese.

METHODS

We retrospectively evaluated 48 (96 knees) patients who were obese and divided into two groups based on their body mass indices (BMI). Morbidly obese patients (group A1, BMI > or = 40 kg/m2) consisted of 21 patients (42 knees), and obese patients (group A2, BMI > or = 30 kg/m2) consisted of 27 patients (54 knees). The control group (group B, BMI < 30 kg/m2) consisted of 20 non-obese patients (40 knees), who were undergoing staged bilateral procedure within the same time frame. All patients had cemented TKAs with use of posterior cruciate sparing prosthesis without patellar resurfacing. If medically stable after the first arthroplasty the patients then underwent the second arthroplasty 4-11 days later. The data on major complications and minor complications were evaluated.

RESULTS

Although, there was no statistically significant difference in overall complication rates in any of the groups, the non-obese group had fewer wound complications than the other groups (P > 0.05). No significant differences in preoperative or postoperative Knee Society score, and functional score could be demonstrated between the three groups (P > 0.05). Both obese and nonobese patients showed improvements in pain and function from pre-surgery to a minimum 2 years follow-up.

CONCLUSION

Results of bilateral staged TKAs in obese patients have low complication and high success rates and increased BMI has no negative effect on the early outcome. Bilateral staged TKA might be a good treatment alternative for the improvement of the patient's quality of life and functional and clinical outcomes.