Unstable Trochanteric Fractures in Elderly Osteoporotic Patients: Role of Primary Hemiarthroplasty

Abstract

Objective

Unstable intertrochanteric fractures in osteoporotic patients are difficult to treat. Fixation failure often leads to prolonged morbidity and poor functional outcomes. The objective of the present study was to investigate primary replacement as a suitable option that could minimize complications in selected patients.

Methods

From January 2004 to March 2007, 28 elderly osteoporotic patients with unstable intertrochanteric fractures were included in this study. Their fractures were classified according to the AO/OTA classification (8 patients, 31A2.2; 17 patients, 31A2.3 and 3 patients, 31A3.3) and their osteoporosis was confirmed by bone densitometry. Hemiarthroplasty was performed in all patients and the outcomes analyzed using the Harris hip score system.

Results

Of the 28 patients, 19 were women and the mean age was 79 years (range, 52–95 years). At a mean follow up of 4.2 years (range, 3–6 years), there were 17 excellent, 7 good, 2 fair and 2 poor results according to the Harris hip score system.

Conclusion

In elderly osteoporotic patients with unstable intertrochanteric fractures, hemiarthroplasty is a reliable alternative to internal fixation. The functional outcome has been encouraging and we suggest it as a method of treatment in this group of patients.

Introduction

Hip fractures most often affect the elderly and have a tremendous impact on both the health care system and society in general1. They account for more than 20% of bed occupancy at any given time in orthopaedic wards and 87% of the total cost of all fragility fractures2. The mortality rate increases after these fracture, life expectancy equalizing that of the normal population by eight months after injury3, 4.

Most unstable intertrochanteric fractures can be successfully treated by open/closed reduction and internal fixation. However in selected patients with osteoporosis and unstable fracture patterns, it can result in cut‐out of implants, delayed full weight bearing or profound long‐term functional disability4, 5. Failure rates as high as 56% have been reported after internal fixation in this group of patients5. The other disadvantage of internal fixation in these patients is the requirement for strict weight bearing compliance regimes and regular follow‐ups due to risk of implant failure and osteonecrosis5, 6, 7. Compliance is an issue due to the increased rates of dementia in this cohort. Secondary replacement for failed internal fixation is technically more complicated and the results are unpredictable6, 7.

Primary endoprosthetic replacement helps patients to achieve their pre‐injury levels of activity more quickly and prevents the post operative complications caused by immobilization or implant failure8, 9. In most reported studies special prostheses (calcar replacement) have been used and the surgical techniques have not been explained properly8, 9. The purpose of the present study was to highlight the surgical technique of Thomson/Bipolar hemiarthroplasty and to evaluate the outcome following its use in patients with unstable intertrochanteric fracture and osteoporosis.

Materials and Methods

This prospective study was conducted between January 2004 and March 2007. Intertrochanteric fractures were classified according to the AO/OTA classification10: eight patients were classified as 31A2.2; 17 as 31A2.3 and 3 as 31A3.3. Strict inclusion and exclusion criteria were followed (Table 1). Osteoporosis was confirmed by bone densitometry results (T‐score below −2.5). Implants used included cemented bipolar prostheses (Zimmer, Warsaw, IN, USA) and cemented Thompson prostheses (Inor, Mumbai, India). There were 9 male and 19 female patients, in whom 17 fractures were on the right side and 11 on the left.

Table 1.

Inclusion and exclusion criteria

Inclusion criteria	Exclusion criteria
Unstable inter‐trochanteric fractures	Stable fractures
Osteoporosis (T score below −2.5)	Unstable fractures without osteoporosis
	Fractures extending into the diaphysis
	Arthritis
	Pathological fractures (excluding osteoporosis)
	Failed internal fixation

Surgical Technique

Either general or epidural anesthesia was administered after the patient had been placed in the lateral position. Twenty‐three patients were operated on using the lateral (Hardinge) approach, whereas in the remaining five a posterior (Moore's) approach was used. After exposing the neck of femur the posteromedial fragment was stabilized with a bone reduction clamp (Fig. 1). The neck was then osteotomized and the head removed with a corkscrew. In patients with comminution of the posteromedial cortex, the gap was reconstructed using bone harvested from the femoral head. The reconstructed posteromedial wall was then stabilized with 18‐gauge cerclage wire (stainless steel) (Fig. 2). The femur was prepared and the prosthesis inserted gently without disturbing the reconstructed proximal femur. Care was taken to avoid injury to the sciatic nerve by identifying it before proximal femoral reconstruction. In patients where the greater trochanter had been avulsed with its abductor mechanism, it was anchored to the main fragment using 18‐gauge cerclage wire (stainless steel), in a figure of eight fashion (Figs 2, 3). If, after stabilization of the posteromedial fragment, the abductor mechanism was intact, figure of eight cerclage wire was not used (Fig. 4). In our study all the patients received aspirin (150 mg) daily for six weeks post‐operatively as prophylaxis for deep vein thrombosis. Intravenous antibiotic prophylaxis (cefuroxime 750 mg three times daily) was given routinely to all patients for 48 hours. All patients were allowed immediate full weight bearing postoperatively. The patients were reviewed, including assessing the Harris hip score, at 3, 6, and 12 month intervals and yearly thereafter11, 12.

Figure 1.

Operative procedure: the posteromedial fragment is stabilized with a bone reduction clamp and then the neck osteotomized with a bone saw and the head removed with a corkscrew.

Figure 2.

Operative procedure: the greater trochanter is reattached using 18‐gauge cerclage wire (stainless steel), in a figure of eight fashion (black arrow). The posteromedial fragment is stabilized using 18‐gauge stainless steel cerclage wire (yellow arrow)

Figure 3.

A 72 male patient with posteromedial comminution and intact lateral wall. (a) During the operation, the fracture was found to extend more than 1 cm below the lesser trochanter (31‐A2.3‐OTA classification). (b) The posteromedial fragment with lesser trochanter was stabilized using 18‐gauge stainless steel cerclage wire and cemented bipolar hemiarthroplasty performed. The greater trochanter was reattached using 18‐gauge cerclage wire (stainless steel), in a figure of eight fashion.

Figure 4.

An 82 female patient with a large posteromedial fragment and intact lateral wall. (a) During the operation, the fracture was found to extend less than 1 cm below the lesser trochanter (31‐A2.2‐OTA classification). (b) The posteromedial fragment with lesser trochanter was stabilized using 18‐gauge stainless steel cerclage wire and a cemented Thomson hemiarthroplasty performed.

Results

The mean patient age was 79 years (range, 52–95 years). Twenty‐two patients had surgery within 24 hours of fracture whilst the remaining six were delayed for anaesthetic reasons (<72 hours). The mean blood loss was 550 mL (range, 300–1700 mL) with a mean operating time of 90 min (range, 70–210 min, excluding anesthesia time). The mean duration of hospital stay was eight days (range, 5–22 days). The patients' co‐morbid conditions included type 2 diabetes mellitus (19 patients), hypertension (17 patients), coronary artery disease (5 patients), chronic renal failure (7 patients), and chronic obstructive lung disease (2 patients). Of the seven patients with chronic renal failure, two had kidney transplants and the others were receiving dialysis.

At a mean follow up of 4.2 years (range, 3–6 years), there were 17 excellent, 7 good, 2 fair and 2 poor results according to the Harris hip score system. The eight patients with 31A2.2 type fractures all had excellent scores. Of the 17 patients with 31A2.3 type fractures, nine had excellent scores, seven good and one poor. Of the three patients with 31A3.3, one had a good score, one fair and one poor.

Complications

Shortening was noted in four patients, in two immediately after surgery (<2 cm) and in the other two later (one at four and the other at five year follow‐up), these being due to sinking of the prosthesis and cement into the osteoporotic proximal femur. These patients had no functional limitations, three having good and one excellent Harris hip scores at final follow‐up.

One patient had a peri‐prosthetic fracture with dislocation (due to a fall) a year after surgery, this patient had open reduction and reattachment of the avulsed greater trochanter using an 18‐gauge stainless steel wire. This patient had a poor Harris hip score at final follow‐up. The other patient with a poor score had multiple dislocations due to anteversion of the prosthesis. This patient had multiple closed reductions and was listed for total hip replacement. Because of co‐morbid conditions, the patient eventually underwent excision arthroplasty. Our patients had no aseptic loosening, peri‐prosthetic infections, ectopic ossification or injuries to nerves and vessels.

There were five deaths during follow up; none of them being peri‐operative. Two were due to pneumonia at six months post‐surgery and the other three due to cardiac and renal causes at two years.

Discussion

Most intertrochanteric fractures can be treated by internal fixation13. However, in a small percentage of patients, the fractures fail to heal because of the initial fracture pattern, comminution and inadequate implant hold on the bone due to poor bone quality5, 13. Failed treatment of hip fractures leads to profound functional disability and pain14. Hip arthroplasty is a reliable alternative in patients with comminuted trochanteric fractures and osteoporosis9, 15. Despite its technical challenges, there is a surprisingly low rate of serious orthopaedic complications with this procedure14.

The aim of treatment of hip fractures in the elderly is to prevent the complications of recumbency by making early mobilization possible and helping patients to return to their daily activities16. Surgical treatment facilitates early rehabilitation with improved quality of life and function. In patients with osteoporosis and unstable fracture patterns, dynamic hip screws and intramedullary devices are associated with higher rates of non‐union, varus collapse, screw cut‐out, rotational deformity and shortening14, 15, 17, 18. The complications following internal fixation are reduced to half when bone quality is good and there is no osteoporosis18. Patients who regain their independence have significantly lower mortality rates19. In this elderly cohort of patients with various comorbidities, it is difficult to maintain compliance with partial weight bearing. This obviously prolongs the duration of hospital stay in these patients and potentially predisposes them to further falls. In addition, they need regular outpatient follow‐up to assess fracture healing, osteonecrosis and implant position.

To overcome the complications related to internal fixation, some authors have suggested that arthroplasty be used for these fractures8, 9, 20, 21, 22. Because it allows early post operative weight bearing and avoids excessive collapse at the fracture site, primary prosthetic replacement is the method of choice20, 23, 24. Sonstegard et al. tested the stability of the cemented prosthesis‐fracture complex and found that it to be significantly greater than any nail‐reduction complex tested. They found that it was able to withstand a maximum load of about 1007 kg, which is far in excess of the loading forces encountered during normal ambulation25.

The average operating time is reportedly shorter, the mortality rate lower, and the functional results better in the group treated with bipolar hemiarthroplasty than in groups treated with Ender nailing, angled blade‐plates, or a dynamic hip screw fixation24. In patients treated with arthroplasty, rehabilitation is easier and faster and the incidence of pressure sores, pulmonary infection and atelectasis significantly lower (P < 0.05)26. Rapid return to pre‐fracture levels of activity essentially prevents any flare up in these elderly patients' co‐morbid conditions19, 26, 27. Early full weight bearing is considered to be the major beneficial factor.

Though the functional outcome is good in patients who have total hip replacements, their use in patients with normal joints is questionable. Major disadvantages include the higher rate of dislocation, high cost and morbidity related to surgery. Calcar replacements are expensive and require removal of large portions of the proximal femur8, 23. In our study, we reconstructed the posteromedial cortex and stabilized it with stainless steel wire. The anatomy was restored and the resulting “cemented prosthesis–fracture complex” is a stable configuration.

In the present study, there were fewer complications related to dislocation and shortening than in other reported series9, 28, 29, 30. This is because we reconstructed the proximal femur anatomy before prosthesis implantation. Potential problems associated with prosthetic replacement, such as loosening, acetabular erosion, stem failure, late infection and late dislocation were not seen in our study at a mean follow up of 4.2 years (range, 3–6 years). The limitations of our study include the small number of patients; the strict inclusion criteria dictated this. In our experience, primary endoprosthetic replacement provides satisfactory results with good functional recovery. Due to the unstable nature of these fractures, internal fixation is not a suitable option, especially in the presence of osteoporosis. Our procedure also obviates the possibilities of nonunion, delayed union, mal union, nail (or) screw cut through and varus collapse. It is also cost effective because there are fewer reoperations, decreased duration of hospitalization, less requirement for nursing care and improved function8, 9, 15, 24, 28, 29, 30. A long‐term study with a large number of patients is required to address the issues of late complications and whether the reconstructions are durable enough for long surviving patients.

Conclusions

Primary hemiarthroplasty is a reliable, technically simple and a safe procedure in elderly patients with unstable intertrochanteric fractures and osteoporosis. The major advantages are immediate full weight bearing and rapid rehabilitation. It decreases the duration of hospital stay and the problems associated with long periods of inactivity such as pneumonia, venous thrombosis, pulmonary embolism and decubitus ulcers. This procedure has fewer complications and a lower reoperation rate with early return of preoperative mobility status than other procedures described in published reports.