Introduction

Long stem cemented hip arthroplasty, whether total or hemi, is fast becoming an established form of treatment in cases of proximal femoral fractures in the elderly. Internal fixation in these cases can lead to a higher incidence of fracture non-union and implant failure, especially when dealing with pathological bone, in cases of osteoporosis and metastasis.

We report four cases of the use of the long femoral stem cemented prosthesis for replacement of the proximal femur.

Case Summary

Case 1

This is an 87 year old lady who was premorbidly ambulant, had a fall at home. She has an Austin-Moore hemiarthroplasty hip prosthesis done for her left side many years ago for a femoral neck fracture. Due to the fall, she sustained a periprosthetic fracture around the Austin-Moore stem which was spiral in configuration and extending up to the proximal femur. We treated her fracture surgically by removal of the Austin-Moore stem and insertion of a long femoral stem total hip replacement (totally cemented). She is currently walking full-weightbearing with the aid of a walking frame.

Figure 1

Figure 1a: Preoperative xray

Figure 2

Figure 1b: Postoperative xray

Case 2

An 85 year old lady had a fall in the bathroom and sustained a comminuted fracture of the right proximal femur at the intertrochanteric region with extension to the subtrochanteric area and also an associated intracapsular neck fracture ipsilaterally.

We treated her surgically by a right hip hemi-arthroplasty using a bipolar prosthesis with a long femoral stem. Postoperatively, she was able to ambulate on walking frame.

Figure 3

Figure 2a: Preoperative radiograph

Figure 4

Figure 2b: Postoperative radiograph

Case 3

A 51 year old lady with advanced breast carcinoma and multiple bone metastases presents with a sudden pain and weakness of the left thigh. Radiograph revealed osteolytic lesion to the left proximal femur at the subtrochanteric region. There was a pathological fracture at the subtrochanteric region secondary to metastatic breast carcinoma. We proceeded to do a bipolar hemiarthroplasty of the left hip using a long femoral stem. Postoperatively, the patient was initially put on wheelchair ambulation and later started on ambulation by walking frame.

Figure 5

Figure 3a: Preoperative radiograph

Figure 6

Figure 3b: Postoperative radiograph

Case 4

A 66 year old male presented with a history of limping and right hip pain 1 month prior to admission to the ward and a 3 day history of sudden inability to weight bear on the right side. He also has loss of weight and loss of appetite. Plain radiograph showed a pathological subtrochanteric fracture of his right proximal femur with osteosclerotic lesion over the entire proximal femur. There was also osteolytic erosion of the ipsilateral acetabulum. We proceeded to do a right totally cemented total hip arthroplasty with a long femoral stem. Postoperatively, the patient ambulated on a wheelchair.

Figure 7

Figure 4a: Preoperative radiograph

Figure 8

Figure 4b: Postoperative radiograph

Discussion

In the treatment of any proximal femoral fractures, whether pathological due to tumor deposits or osteoporosis, there are two issues which need to be addressed:

1. Adequate stability for immediate weight bearing and

2. The prosthesis should bypass the abnormal bone to obtain a stable and strong construct.

Case 1 is a periprosthetic fracture around an Austin-Moore femoral stem. The fracture extended spirally up to the proximal femur. Revision with a conventional length stem would not have been adequate because of the extent of the fracture as well as inadequate bone stock, which is a common problem in revision arthoplasty [₁]. Cemented long-stem femoral components, compared to cemented conventional-length stems decreases the extent and progression of femoral lucencies, thereby lowering the incidence of mechanical failures and improving long-term survival of the prosthetis.[₁]

In case 2, the patient had a comminuted fracture of the proximal femur around the peritrochanteric area. There was also an associated intracapsular femoral neck fracture. The risk of avascular necrosis of the femoral head and non-union of the neck fracture is likely to be high. Therefore, fixation with an intramedullary device such as a gamma nail or proximal femur nail is contra-indicated. As such, replacement of the proximal femur with a femoral stem prosthesis was chosen.

In cases 3 and 4, there was a pathological fracture of the proximal femur due to metastatic disease. Healing of pathological fractures cannot be relied on because healing generally proceeds more slowly than normal, is impeded both by the metastatic tumor and by the effects of postoperative radiation treatment [₂].For lesions about the hip, where as much as six times body weight may be borne by the bone, the need for immediate stability and prolonged durability strongly favors prosthetic replacement rather than internal fixation. [₂] Internal fixation of pathological fractures or impending pathological fractures that are due to metastatic involvement of the femoral head and neck region is associated with an unacceptably high risk of subsequent pathological fracture. Thus, in cases 3 and 4 prosthetic replacement is the treatment of choice [₂]. As for the length of the femoral stem, in all the 4 cases described, we chose long stem femoral implants, measuring at least 20 cm. From a biomechanical standpoint, the tip of the intramedullary femoral stem should bypass the most distal area of weakness by two bone diameters. This minimizes stresses and motion that could be associated with clinical loosening of the cemented stem. [₂,₃]. A shorter stem that just bridges the fracture may not provide adequate distal fixation due to high cement-bone shear stresses [₂,₃].

Correspondence to

Dr Vivek Ajit Singh Department of Orthopaedic Surgery University of Malaya 50603 Kuala Lumpur Malaysia Telephone: + 60 3 7949 2061/ 2446 Fax: + 60 3 7949 4642 Email: drvivek69@gmail.com