Nigerian Medical Journal

ORIGINAL ARTICLE
Year
: 2015  |  Volume : 56  |  Issue : 1  |  Page : 64--68

Early result of hemiarthroplasty in elderly patients with fracture neck of femur


Mue Daniel1, Salihu Mohammed2, Awonusi Francis2, Yongu William1, Kortor Joseph1, Elachi Cornilius1,  
1 Department of Surgery, Benue State University, Makurdi, Nigeria
2 Department of Clinical Services, National Orthopaedic Hospital Dala, Kano, Nigeria

Correspondence Address:
Mue Daniel
Department of Surgery, Benue State University, Teaching Hospital, Makurdi
Nigeria

Abstract

Background: Fractured neck of femur is a frequent and severe injury in elderly patients with consequent high morbidity and mortality. Hemiarthroplasty is an established treatment modality for displaced intracapsular femoral neck fractures in elderly patients above 60 years. This study analysed the early functional outcome and complications of Austin Moore endoprosthesis in elderly patients above 60 years with fractured neck of femur. Materials and Methods: Retrospective data were obtained over a 5 year period from January 2007 to December 2012. Thirty-five elderly patients of 60 years and above with displaced intracapsular fracture neck of femur treated with hemiarthroplasty using Austin Moore endoprosthesis were included. Data were analysed using SPSS version 21. Results: A total of 35 patients were involved. The age-range was 60-90 years with mean age of 69.7 ΁ 7 years. The predominant mechanism of injury was trivial falls in 18 (66.7%) patients. The commonest complication was pressure sore in 2 (5.7%) patients, followed by surgical site infection in 1 (2.9%) patient and periprosthetic fracture in 1 (2.9%) patients. Early post-operative mortality was 2.9%. Post-operative hip functional status according to Postel and Merle d Aubigne revealed that majority (66.6%) of patients had satisfactory hip function. Conclusion: Functional outcome of Austin Moore in elderly patients above 60 years with fracture neck of femur was satisfactory in most of the cases with minimal morbidity. Careful patient selection for hemiarthroplasty is vital and may decrease the incidence of complications and ameliorate the outcomes in the treatment of intracapsular femoral neck fractures.



How to cite this article:
Daniel M, Mohammed S, Francis A, William Y, Joseph K, Cornilius E. Early result of hemiarthroplasty in elderly patients with fracture neck of femur.Niger Med J 2015;56:64-68


How to cite this URL:
Daniel M, Mohammed S, Francis A, William Y, Joseph K, Cornilius E. Early result of hemiarthroplasty in elderly patients with fracture neck of femur. Niger Med J [serial online] 2015 [cited 2019 Dec 10 ];56:64-68
Available from: http://www.nigeriamedj.com/text.asp?2015/56/1/64/149174


Full Text

 INTRODUCTION



Femoral neck fracture is a frequent and severe injury in the elderly with associated high mortality and morbidity. The incidence of these fractures has increased with improvement in life expectancy and is expected to double in the next 20 years and triple by 2050. [1] Mortality rate of 20-30% in the year following the fracture has been reported. [1] Management poses a challenge to the orthopaedic surgeon especially in the elderly patient with medical co-morbidities.

Although surgical treatment is the gold standard, the best surgical treatment option is still to be determined. [2] Hip replacement arthroplasty (partial or total) is emerging as the most viable treatment option and a broader consensus has been reached as regards its benefits which allow immediate weight bearing, early restoration of premorbid activity and enhanced quality of life in elderly patients. [3]

Studies by Rogmark et al., [4] and Roden et al., [5] showed complications of non-union, avascular necrosis and a high rate (30-40%) of reoperation following internal fixation and superior function after primary hemiarthroplasty which eliminates these complications as the femoral head and neck is replaced by metallic implant. [6] Although unipolar hemiarthroplasty with Austin Moore prosthesis is rarely employed in the developed countries, it is still commonly used in developing countries where it is reserved for elderly, very limited or non-ambulatory, low-demand patients with relatively shorter life expectancy. [2] Calder et al., [3] found no statistical difference in the complication rates following the use of unipolar and bipolar endoprosthesis in treating displaced hip fractures in octogenarians, and that the degree of return to the pre injury state was significantly greater when using the Austin Moore unipolar endoprosthesis. Frihagen et al., [7] in their study on the functional outcomes of Austin Moore endoprosthesis versus bipolar prosthesis have shown the end result to be the same.

There is paucity of published literature on functional outcome of hemiarthroplasty among elderly patients in our environment. The objective of this study was to share our experience on the early functional outcome and complications of cementless unipolar hemiarthroplasty with Austin Moore endoprosthesis in elderly patients above 60 years with fractured neck of femur.

 MATERIALS AND METHODS



This is a 5 year retrospective study from January 2007 to December 2012, conducted at Nongo u Krestu u i Ser u sha Tar (NKST) rehabilitation Hospital Mkar, North Central Nigeria. Thirty five elderly patients aged 60 years and above with displaced intracapsular fracture neck of femur were operated by 3 orthopaedic surgeons using Austin Moore endoprosthesis were included in the study. Patients having pre-existing symptomatic acetabular diseases (Rheumatoid arthritis, ankylosing spondylitis, tuberculosis, Paget's disease), multiple fractures and any form of infection or a life threatening medical conditions were excluded from the study. The post-operative complications and hip functional status of patients was assessed according to the hip functional scale of Postel and merle d Aubigne (PMA) [Table 1] and [Table 2] after at least 4-6 months of follow-up.{Table 1}{Table 2}

The following variables were studied: Mechanism of injury, duration of fracture, associated systemic illness, complications and post-operative hip functional status.

The data was analysed for frequencies of various variables. Statistical programme for social science (SPSS) version 21 was used to analyse the data. Effect modifiers like age and gender were controlled through stratification.

 RESULTS



The total number of patients was 35 with 23 males and 12 females. Male to female ratio was of 1.9:1 with a male gender prevailing by 65.7%. The age range was 60-90 years with mean age of 69.7 years.

The predominant mechanism of injury was trivial falls in 18 (66.7%) patients followed by motorcycle accident in 8 (29.6%) patients and vehicular accident in 1 (3.7%) patients. [Table 3] Majority of the women (88.9%) patients were involved in low energy injury trivial falls while more men (87.5% and 100%) patients were involved on high energy injury - motor cycle accident and vehicular accident respectively [Figure 1] and [Table 3]. Only 4 (11.4%) patients presented within 48 hours of injury. Majority of the patients 71.4% presented between 3 week and 1 year of injury. Fifteen (42.9%) patients had one or more systemic co-morbidity such as hypertension (28.6%), Diabetes Mellitus (2.9%) and four (11.4%) patients had both diabetes mellitus and hypertension. Spinal anaesthesia was preferred in most (74.3%) patients as it is safer in these frail elderly patients with systemic comorbidity whose health status is further deranged by trauma, only 8 (29.1%) patients underwent surgery under general anaesthesia. One (3.7%) patients was started on spinal anaesthesia but later converted to general anaesthesia due to wearing out of the spinal anaesthesia from prolonged surgery.{Figure 1}{Table 3}

The most frequently used surgical approach was anterolateral (48.5%) followed by direct lateral (28.6%) and posterior or southern approach (22.9%). Size range of Austin Moore prosthesis used was 42-52 mm. The most frequently used sizes were 44-46 mm with 52.8% cumulative use. Majority (85.8%) patients of the smaller sized prosthesis (42-45 mm) were used by women while (80%) patients men used the larger sizes (46-52 mm) [Figure 2].{Figure 2}

The mean duration of hospital stay was 16 (13-34) days. Mean duration of surgery was 113 (75-135) minutes and mean estimated blood loss was 330 mls. Fifty five percent of patients required at least one unit of blood transfusion. Majority of the patients (91.4%) walked with some form of external support during the hospitalisation period. Two patients (5.7%) had mental derangement and refused to co-operate with physiotherapy and one patient (2.9%) was discharged against medical advice.

The commonest complication was pressure sore in two patients (5.7%), followed by surgical site infection in one patient (2.9%) and periprosthetic fracture in 1 patient (2.9%). [Table 4] Early post-operative mortality was 2.9%.{Table 4}

Follow-up time of patients was poor as patients default frequently after a few visits. Five patients (14.2%) were lost to follow-up and were never seen after discharge in the surgical outpatient department. Only 21 patients (60%) were seen at 6 months follow-up, six patients (17.1%) at 1 year follow-up and only one patient (2.9%) was seen after 1 year.

Post-operative hip functional status done according to Postel and Merle d Aubigne scoring system [Table 1] and [Table 2] at 4-6 months post-operation revealed that majority of the surviving patients (69%) had satisfactory (Good, Very Good and Excellent) post-operative hip functional score[Figure 3].{Figure 3}

 DISCUSSION



Intracapsular fractures of the proximal femur form a major share of fractures in the elderly. Osteoporosis, co-morbidities, increased incidence of trivial trauma increases the incidence and complicates the treatment of these fractures.

There was a male preponderance observed in this study with a male female ratio was of 1.9:1. This gender variation is similar to results obtained in some loco regional studies by Onche et al., [8] Aristote et al., [9] but at variance with western studies by Dhar et al., [10] and Syed et al., [11] where the female gender prevails in view of higher incidence of osteoporosis. Lauritzen et al., [12] in their study observed that when comparing race, Caucasians are more likely to suffer hip fractures more than any other race and reported that African Americans and Hispanics are the least likely to suffer hip fractures, which is sought to be attributed to a higher bone density found in both of African Americans and Hispanics. The mean age of 69.7 ± 15 years obtained in this study is similar to 67.4 years by Onche et al., [8] and 65 years by Essoh et al., [13] but at variance with 72 years by Dhar et al., [10] and 83.5 years by Syed et al., [11] which reflects the higher life expectancy of those countries.

The predominant mechanism of injury was trivial falls in 18 (66.7%) patients this is in keeping with previous studies. [8],[9] Eight (29.6%) patients were involved in motorcycle accident reflecting the recklessness of motorcyclist as a common etiology for trauma in developing countries. [8],[9] Majority of the women (88.9%) were involved in low-energy injury - trivial falls which reflects the higher incidence of osteoporosis in women [8],[9],[10],[11],[12] while more men (87.5% and 100%) were involved on high energy injury - motor cycle accident and vehicular accident respectively.

There was delay in presentation as majority 31(88.6%) of patients presented after 48 hours of injury of whom 71.4% presented between 3 week and 1 year of injury. This late presentation and probable worsening of fracture displacement from repeated manipulation by traditional bone setters may have caused additional trauma and potential vascular insult. [13] This reflects the activities of these traditional healers and bone setters in developing countries who dabble into fracture management without regulation. [8],[9]

Cement less Austin Moore endoprosthesis was used in all cases. Bone cement has been shown to adversely affect pulmonary and cardiovascular function during the conduct of surgery and the immediate postoperative period which may be poorly tolerated in the elderly with pre-existing cardiopulmonary comorbidity. Pavarzi et al., [14] demonstrated the incidence of intraoperative death contributed by the use of acrylic bone cement during hip hemiarthroplasty to be less than 0.2%. Stavrakis et al., [15] in his study to assess the effectiveness of cement less Austin Moore and the cemented Thompson prostheses used in the treatment of displaced intracapsular fractures of the proximal femur, found that though advantages and disadvantages were identified in both groups, none of the techniques proved definitively superior to the other. The risk of intraoperative complications related to the use of cement may be reduced by venting the femur, avoiding excessive pressurization during insertion and adequate preoperative hydration.

Although Austin Moore's prosthesis eliminates the chances of non-union and avascular necrosis, other complications still occurred. The commonest complication encountered in this study was pressure sore in two patients (5.7%). This was Shea grade 1 which healed uneventfully following daily dressing and mobilisation of the patients. Early graded mobilisation is advocated in these patients to forestall this complication. Abduction pillow if used should be discontinued early after 4-5 days.

The infection rate in the present study was 2.9%. This was superficial surgical site infection and was treated by removal of alternate stitches, daily wound dressing and antibiotics therapy according to sensitivity pattern. Previous studies reported crude infection rate of 0% by Sicand et al., [16] 4.7% by D'Arcy et al., [17] and 20% by Onche et al., [8] Essoh et al., [13] reported deep surgical site infection necessitating removal of prosthesis and conversion to Girdlestone excision arthroplasty. The rate of infection was kept low by proper preoperative preparation, general measures for keeping operation room clean, use of impervious drapes by routine use of prophylactic antibiotic, and keeping such patients in the ward away from the infected patients. The infection rate has been reported to be higher when posterior approach is used for arthroplasty due to proximity of incision to the perineum. This was however not reported in this study.

Intraoperative periprosthetic fracture was encountered in 1 (2.9%) patient. This was Vancouver Type A2 fracture which was identified during the procedure and managed with cerclage wire, cementing the prosthesis was not required as fracture was considered stable. This is in similar to previous incidence of 6.8% by Fernandez et al., [18] 11.8-14.0% by Weinrauck et al. [19] Most fractures are often sustained during dislocation of head of femur from acetabulum, impaction of the prosthesis after broaching or during its reduction. Under broaching and relative oversizing of the stem with intent to provide interference fit of the prosthesis in osteoporotic bone may result in fracture during prosthesis insertion. Previous studies by Weinrauch et al., [19] and Parker et al., [6] have reported a statistically significant increased incidence of periprosthetic fractures in uncemented Austin Moore prosthesis. Options available to minimize intraoperative periprosthetic fractures include; Proper patient positioning, adequate lateralization of the broach, adequate soft tissue release, routine use of narrow stem prosthesis or cementing the Austin Moore prosthesis.

Early post-operative mortality was 2.9%. Previous studies reported one year post-operative mortality rate of 8.3% by Essoh et al., [13] 15% by Syed et al., [11] 11.1% by Aristotle et al., [9] and 38% by Sicand et al., [16] in elderly patients treated by Austin Moore prosthesis. The rate of mortality depends on age of the patients and systemic medical comorbidities [12],[16] which may be minimised by careful patient selection, proper pre-operative optimisation, adequate thrombo prophylaxis and early post-operative mobilisation.

Follow-up time of patients was poor as patients default frequently after a few visits. Five (14.2%) patients were lost to follow-up and never seen after discharge in the surgical outpatient department. Only 21 (60%) patients were seen at 6 months follow-up, 6 (17.1%) patients at 1 year follow-up and only one (2.9%) patient was seen after 1 year. This inconsistent follow-up and difficulty in contacting our patients made it challenging to accurately ascertain the post-operative mortality pattern as some deaths had probably occurred at home after the last consultation.

Post-operative hip functional status done according to Postel and Merle d Aubigne scoring system revealed that majority (69%) of patients had satisfactory hip function (Good, Very Good and excellent) post-operative hip functional score [Figure 3]. This is in keeping with previous studies which reported 76% satisfactory score by Ahmad et al., [20] 59% by Syed et al., [12] and 82% by D'Arcy et al. [17]{Figure 3}

 CONCLUSION



Functional outcome of Austin Moore in elderly patients with fracture neck of femur in terms of pain relief, mobility and restoration of function as near as possible to the pre-injury level was satisfactory in majority of cases with minimal morbidity. Careful patient selection for hemiarthroplasty is vital and may decrease the incidence of complications and ameliorate the outcomes in the treatment of displaced intracapsular femoral neck fractures. This study suggests primary hemiarthroplasty with Austin Moore endoprosthesis may be favoured in the treatment of displaced intracapsular fracture neck femur in elderly patients above 60 years.

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