Total Hip Arthroplasty for Hip Fractures

Abstract

Introduction:

This study aimed to determine the dislocation and reoperation rate, functional outcomes, and the survival rate of the unique subset of very old but lucid and independent patients with hip fractures following a total hip arthroplasty (THA) and geriatric team-coordinated perioperative care.

Method:

Between 2000 and 2006, previously independent ambulatory patients ≥80 years old presenting with an intracapsular hip fracture were given THAs under the care of an integrated orthopedic surgery–geriatric service. Their fracture-related complications, ambulation, mental status, and survival were followed for 5 to 11 years postinjury.

Results:

Five years postinjury, 57 (61.3%) patients of the original study group were living. In all, 3 (3.2%) patients had postoperative hip dislocations (and 2 patients had dislocation twice) and 2 reoperations were needed within the first postoperative month. There were no hip dislocations or reoperations after the first year. Radiographs obtained on 88% of the surviving patients at 5 years postoperatively showed that all remained unchanged from their immediate postoperative images. Nearly half of the patients were still able to ambulate as they did preoperatively and their mixed-model equation was statistically unchanged.

Conclusion:

This study of patients >80 years old with previously good functional status demonstrates that with appropriate surgical (best prosthesis, good operating technique, and regional anesthesia) and geriatric (pre- and postoperative assessments, close follow-up, medication adjustments, and fall-prevention instruction) care, they have few hip dislocations and reoperations, survive postfracture at least as long as their noninjured contemporaries, and continue to function and ambulate as they did prior to their injury.

Introduction

Elderly patients annually sustain more than 1.6 million hip fractures worldwide; this number will significantly increase over the coming decades as the population ages.^1,2 Three-quarters of all hip fractures occur in women, with a lifetime risk of having any osteoporotic fracture ranging between 40% and 50%, as opposed to only a 13% to 22% risk in men.^2,3 As people age, the incidence of hip fractures increases, with individuals aged 85 years 10 times as likely to have hip fractures as those aged 65 to 69 years.⁴

With standard posthip fracture interventions, 13.5% of older adults die within 6 months after injury and 24% within 1 year. This pattern continues for more than a decade postinjury.^5-7 At 6 months postinjury, only 50% of patients can perform their prefracture activities of daily living (ADLs) and only 25% can perform instrumental ADLs, activities that let an individual live independently in a community.^8,9 At 1 year posthip fracture, older adults are 5 times more likely to be institutionalized than age-matched controls without hip fracture.^10,11

Ideally, independent elderly patients receive hip fracture treatment, which not only reduces the incidence of postoperative dislocations and reoperations but also restores them to their prefracture baseline mobility, reduces any diminution in their mental status, allows them to continue their prior lifestyle, and reduces premature mortality.¹¹

Although in low demand, hemiarthroplasty is the preferred surgical treatment for hip fractures, and cognitively impaired elderly patients and healthy active patients may have better functional outcomes from a total hip arthroplasty (THA).^12-14 Some centers have reported a high dislocation rate with THAs. Factors to be considered when making a decision to use THA in this population include the patient’s age, risk profile, functional demands, cognitive function, and physical fitness.^15,16 Studies have shown that not only the type of surgery but also special perioperative geriatric care plays a large role in limiting orthopedic complications and returning previously functioning elderly patients with hip fracture to their premorbid living condition.^17,18

This study aimed to determine the dislocation and reoperation rate, functional outcomes, and the survival rate of the unique subset of very old but lucid and independent patients with hip fractures following a THA and geriatric team-coordinated perioperative care.

Materials and Methods

Patient Recruitment

Between January 2000 and August 2006, patients presenting with a fractured hip to the Hospital Italiano-San Justo emergency department were asked to join the study if they met the inclusion criteria.

Inclusion and Exclusion Criteria

Inclusion criteria for this study required being >80 years old, having a nonpathological intracapsular hip fracture, the ability to walk autonomously ≥0.5 km before the injury, a hip with no or minimal arthritic changes, and a normal preoperative abbreviated Mini-Mental Test score. Exclusion criteria were medical or physical comorbidities that limited the ability to walk preinjury, preexisting hip abnormalities requiring a THA, or a pathological fracture (Table 1). This resulted in enrolling 93 patients aged 80 to 95 years (average 83.2 years). The female–male ratio was 65:28 (likelihood ratio 2.3) and their nonstop walking distance was 0.5 to 5.7 km (average 1.7 km). Their preoperative Mini-Mental State Examination scores were 21 to 28 (average 24.5) on a 30-point scale and a median American Society of Anesthesiologists Physical Classification System score was 2 of the 6 (“patient with mild systemic disease”¹⁹), with a range of 1 to 4. All patients or their designated surrogates signed an informed consent for the study although the study also had an institutional review board waiver since the study protocol followed the normal standard of care.

Table 1.

Reasons for Noninclusion in the Study.

Patients ≥80 years old presented with hip fractures	117
Incomplete chart	2
Refused to participate in study	12
Patients who we could not follow postoperatively due to their insurance	6
No prior activity-level history	3
Patients prospectively studied (N)	93

Surgical Technique

These patients’ Garden classifications for their fractures²⁰ were 61 type III (65.5%) and 32 type IV (34.5%). The same surgical team performed all operations using a posterolateral approach, releasing and then reattaching the short rotators and conserving the piriformis. The patients received a cemented femoral component with a collarless polished tapered stem (C-stem with Ogee cup, DePuy Orthopaedics, Warsaw, Indiana). The femoral head was 28 mm and the acetabular component was an all-polyethylene cup with a long posterior wall. The mean external diameter of the acetabular component was 47 mm (44-55 mm). The femoral canal was restricted using a plastic plug and sealed using the vancomycin cement-gun technique. Initial postoperative radiographs were evaluated to determine the cementing grade according to Barrack et al.²¹

Spinal anesthesia was used for all but 5 patients. The mean operative time was 72 minutes (range 50-120 minutes). Intraoperative complications included oxygen desaturation during cementation (2 patients), 1 calcar fracture, and 1 greater trocanter fracture. The 2 intraoperative fractures (2.2% compared to reported rates of 5.6%²²) were stable, localized on the greater trochanter, and treated with cerclage so did not require any modification of postoperative weight bearing. Transfusion was needed in 37 (39.7%) patients, with these patients receiving an average of 2 units (1-5). No patient died during surgery. Postoperative anterioposterior and true lateral hip radiographs demonstrated that the acetabular cups were within the expected range of 40° to 50° (mean 43.9°) in 90 (97%) patients. In 86% (80 patients) of patients, acetabular cementation was good. Anteversion was found in the expected range of 0° to 10° in 97.7% of patients; no acetabular cup retroversion was found. Five (5.4%) radiolucent lines were observed with no progression or clinical manifestation during the last patient follow-up examinations. Per Barrack et al grading, femoral cementation was grade A in 79 (84.3%) patients and grade B in 14 (15.7%) patients; 4 lateral separations were observed with no clinical manifestations. Limb length differences ranged from 4 to 15 mm (mean 5 mm).

Perioperative Care

Preoperatively, the patients were housed in an orthogeriatric unit specifically designed to improve operative outcomes in older patients. The unit’s multidisciplinary team of geriatricians, geriatric assistants, and therapists not only care for the patients’ postoperative needs but also perform full evaluations of the patients’ functional performance, nutritional status, and muscle strength. Surgery, scheduled at the earliest possible time, averaged 1.67 days after admission. Postoperatively, patients were allowed to fully weight bear using a walker on day 3. They worked with the fall-prevention specialists and then the in-home treatment team to control balance and walking abilities. During their hospital stay, averaging 14 days (range 6-18 days), 11 patients developed confusional syndromes, 3 had fever syndromes, and 3 had urinary tract infections. Table 2 lists other postoperative complications. On discharge, the patients and their caregivers received written exercises and position control instructions as well as home follow-up by unit-based physiotherapists. They also received instruction on how to make changes at home to help prevent future falls, including the addition of support bars in bathrooms and changing some furniture design or placement, including beds and chairs.

Table 2.

Follow-Up and Complications (N = 93 In Hospital).

Time postoperatively	1 month N = 90	1 year N = 87	5 years N = 57
Hip dislocation with reoperation	2 (2.2%)a	0	0
Hip dislocation with closed reduction	1 (1.1%)	2 (2.2%)a	0
Reoperation—other	0	0	0
DVT	3 (3.2%)	0
PE	1 (1.1%)	0	0
Wound infectionb	1 (1.1%)	0	0
Deaths (during time interval)c	3 (3.2%)	3 (3.2%)	30 (32.3%)
Deaths, year (during time interval—percentage is of original cohort)	–	6 (6.5%)	7.5 (8.1%)
Radiographic change from postoperative images	–	0/87	0/50

Abbreviations: DVT, deep vein thrombosis; PE, pulmonary embolism.

^aOnly 3 patients had postoperative hip dislocations; 2 patients had 2 dislocations and 1 resulted in the revision of their acetabular cup.

^bWound infection required reoperation. After 3 years, there was a line at the bone–cement interface on x-rays, although the patient had no pain. Suppressive antibiotics were administered.

^cAll had functioning prosthesis.

Collection of Outcome Data

Surviving patients were followed for 5 to 11 years (average 6.2 years). Although some patients could describe their pre- and postfracture walking ability (in home and outdoors), this was confirmed with or obtained from relatives, caretakers, or the periodic evaluations performed by their geriatric or family doctors or at the fall-prevention clinic. A geriatrician performed a Mini-Mental State Examination prior to surgery. Clinical evaluation was conducted at 45 and 90 days, 1 year, and then annually. Physiotherapists used Timed Up and Go (TUG) tests to measure initial postoperative ambulation and later compared preoperative and subsequent self-reported walking ability (Table 3).

Table 3.

Walking Ability, Hip Pain ADLs^a and Cognitive Status.

Time postoperatively	In-hospital (postoperative) N = 93	1 month N = 90	1 year N = 87	5 years N = 57
Unchanged TUG and ADLs from preoperative	Not measured	70 (77.7%)	61 (70.9%)	27 (47.4%)
Used walking aid	–	16 (17.8%)	20 (23.3%)	22 (38.6%)
Only in-home activities	–	4 (4.44%)	6 (6.1%)	9 (15.8%)
Reported hip pain	–	0	0	0
Mini-Mental State Test Score average (range)	23 (21–27)	24 (22–27)	24 (23–27)	23 (21–26)

Abbreviations: ADL, activity of daily living; TUG, Timed Up and Go.

^aTUG test at 1 year and self-reported or report from caregiver at 5 years.

Results

Survival rate

Five years postinjury, 57 (61.3%) patients of the original study group were living (Table 2). This compares very favorably to the expected 5-year survival of 80-year-old men (∼55%) and women (∼65%) in the most developed countries.²³

Functional Outcomes

Nearly half of the patients were still able to ambulate as they did preoperatively and their mixed-model equation (MME) was statistically unchanged (Table 3). At 1-month postoperatively, nearly 71% of the surviving patients had TUG tests that were unchanged from their preoperative status. Another 23% could ambulate outside their residence with a walking aid. None reported hip pain. At 5 years postoperatively, about 47% of surviving patients could still ambulate unaided and another 39% used a walking aid. The ADL measures showed similar findings.

Dislocation and Reoperation Rate

There were no hip dislocations or reoperations after the first year (Table 2). During the first year, 3 patients had 5 hip dislocations (2 with 2 dislocations each). In the first month, 2 of them required reoperation and 1 needed a revision of the acetabular cup. The other 3 dislocations were treated successfully with closed reduction. One other patient required reoperation within the first month due to a wound infection. Radiographs obtained from 88% of the surviving patients at 5 years postoperatively showed that all were unchanged from their immediate postoperative images.

Discussion

Morbidity and Mortality

With the high frequency of hip fractures in elderly patients, a major goal is to reduce the postinjury morbidity and mortality. This study demonstrated that this can be done in “old” (74-84 years) and “very old” (85 years and older) patient populations who are ambulatory and autonomous preinjury.²⁴ The 6.4% 1-year and 38% 5-year mortality in this study population may seem high but must be compared to the reported mortality rates of 20% to 38% at 1-year posthip fracture.^7,25,26 This group’s mortality actually appears similar to their nonhip fracture cohorts. On average, an 83-year-old woman (the average age for entry into this study) has a life expectancy of about 7.8 years and a chance of dying within the next year of 6.3%. Men aged 83 years only have a life expectancy of 6.5 years with an 8.7% chance of dying within the next year.²⁷

Delays in surgery contribute to in-hospital mortality.²⁸ Although the timing of surgery often relates to the patient’s underlying medical conditions, surgeons should be available to operate as soon as the patient is stable for a major operation. Along with the appropriate surgical technique and hardware, the average of 1.7 days from admission to surgery may have helped to lessen morbidity and mortality of the patient.

A wide variety of interventions, best implemented by a surgical comanagement with a geriatric team, are known to decrease complications, disability, and mortality in hospital and improve the functional outcome in elderly patients with hip fracture.^11,17,18,29 Key elements that were used in this study population include an early comprehensive assessment of mental and physical abilities, a limited use of geriatric-appropriate acute and chronic medications and doses, early ambulation with balance and fracture-reduction training, additional rehabilitation as necessary, comprehensive discharge planning, and continued follow-up. Early postoperative ambulation almost eliminated the commonly seen hospital complications of delirium, pneumonia, increased mortality, and diminished functional recovery.³⁰ Although most older adults with hip fractures are hospitalized for about 1 week, these patients were hospitalized about twice as long but simultaneously received rehabilitative services and fall-prevention care. They also had close follow-up, especially during the first 45 days postoperatively, allowing clinicians to intervene whenever necessary.

Functional Outcomes

As regards functional ability, prior studies indicate that about 30% of patients with hip fracture require nursing home care, less than half had their original walking ability restored, and nearly 40% lost ADL functions, such as shopping and self-caring.^25,26 In contrast, all patients in this study returned to their original domicile and 71% had a return to their prior functional level of daily activity, including ambulation. Even the 2 patients who had intraoperative fractures had no delay in their ambulation. At 5 years postinjury, 47% of the survivors still maintained their preinjury ambulation level. Most (23%) of the others walked using a walking aid. We believe that walking ability and mental status are the most appropriate methods for evaluating surgical results in very old persons since the goals are patient comfort and function rather than simply implant survival. Achieving these results, however, requires combining appropriate surgical management with skilled pre- and postoperative geriatric care. Whenever possible, general anesthesia was avoided in order to reduce anesthetic risks and postoperative confusion.³¹ Their 5-year MME was statistically unchanged from their initial in-hospital score.

Dislocations/Reoperations

All patients in this study received THAs (as opposed to hemiarthroplasties) based on several factors. The THAs require a shorter time for patients to regain full weight bearing and mobilization, there is less muscle loss, the reoperation rate is lower, and few patients experience painful acetabular erosion (up to 66% for hemiarthroplasties).³²

In this study, 3 (3.2%) patients incurred 5 dislocations, 2 of which needed operative revision. This low incidence of periprosthetic complications is most likely due to the surgeons’ experience, the surgical approach, and the use of cemented stems. Dislocation is the major complication of THAs, with the reported rates ranging from 2% to 20%, the lowest rates being with THAs for nonfracture patients. Dislocations are most common when patients are engaged in simple movements like sitting on the toilet or sleeping on their side. The surgical procedure in these cases included repairing the soft tissues, which has been found to decrease the incidence of dislocation by more than 8 times.³³ Although using the smaller femoral 28-mm head may increase the propensity for dislocation,^34,35 surgical reattachment of the short rotators and piriformis retention as well as our geriatrician’s intense educational and rehabilitation program more than compensated for this difference.³⁶

Limitations

Although patients were enrolled prospectively in this study, some of the information was garnered through retrospective chart review. In addition, the geriatric and close follow-up care our patients received, while normal in our setting, is not generally applicable in many other locations and health care systems. Nevertheless, final functional data from all patients were not based on physician examinations. Results from the relatively limited number of patients studied, however, were not skewed by surgeon bias on operative technique. All the hospital’s elderly patients with hip fractures receive a THA from a team dedicated to doing hip replacement surgery. During the study period, the team also performed 460 elective hip replacements in patients ≥80 years old.

Conclusions

This study of patients >80 years old with previously good functional status demonstrates that with appropriate surgical (best prosthesis, good operating technique, and regional anesthesia) and geriatric (pre- and postoperative assessments, close follow-up, medication adjustments, and fall-prevention instruction) care, they have few hip dislocations and reoperations, survive postfracture at least as long as their noninjured contemporaries, and continue to function and ambulate well as they did prior to their injury.