Dual Mobile Total Hip Replacement in Super Obesity: A Case Report and Review of Literature

Abstract

Introduction: More than 13 million people in the US are morbidly obese. It is associated with various medical and anesthetic complications. Higher rate of dislocation in total hip replacement (THR) associated with morbid obesity due to thigh girth, low muscle mass and high-fat content. Morbid obesity is associated with a 38% increase in the 10-year mortality rate compare to non-obese after undergoing primary total hip arthroplasty (THA). Hip dislocation after THR is one of the earliest complications, and for every ten-point increase in BMI, the risk of dislocation increases by 113.9%.

Case report: We present a case report of a 69-year-old super-obese woman with a BMI of 62.2, who presented with repeated dislocation post THR. The patient was managed successfully with implant removal and implantation of dual mobile THR prosthesis.

Conclusion: Morbid obesity with a need for arthroplasty is challenging. It needs proper planning, thorough preoperative preparation, proper intraoperative care and identification with adequate post-operative complications management. Preoperative bariatric surgery, dual mobile liner and constrained implants have shown good result in decreasing dislocation rate. The liner of dual mobile THR is efficient to prevent post-operative dislocation in morbidly obese and super-obese patients.

Keywords: Dual mobile total hip replacement; bariatric surgery; hip arthroplasty; morbid obesity; neck of femur fracture; revision hip arthroplasty; super obesity.

Figure 1

(a) Initial fracture neck of femur left (b) Surgically treated with Total Hip replacement.

Figure 2

(a) X-ray showing peri-prosthetic dislocation (b) X-ray showing contained implant after closed reduction.

Figure 3

CT images showing left prosthetic dislocation (a) Axial section, (b) Saggital section, (c) 3D reconstruction, (d) Coronal view.

Figure 4

(a) Positioning of the patient, (b) Removal of acetabular shell with an extractor, (c) Acetabular cup implantation.

Figure 5

(a) Acetabular Cup extractor, (b) Old acetabular shell, (c) New acetabular shell, (d) Dual mobile cup, (e) Femoral head assembly preparation with metal on polyethylene.

Figure 6

Single use negative pressure wound therapy device.

Figure 7

Post-operative mobilization. (a) Bedside physiotherapy, (b) Patient able to stand from chair, (c) Patient able to walk with walker.

Figure 8

(a) Pre-operative X-ray showing periprosthetic dislocation, (b) Post-operative X-ray showing dual mobile prosthesis.

Figure 9

One year follow-up. (a) A-Patient able to seat without support, (b) Patient able to stand without support, (c) Walk with help of walker.