Single staged bilateral total hip replacement and its outcomes: A cross-sectional study

Abstract

BACKGROUND

Bilateral hip disorder is a common finding that can occur in approximately 42% of the population with osteoarthritis. It is estimated that 25% individuals with osteoarthritis requiring total hip replacement (THR) may require a bilateral replacement. This has resulted in the test of the greatest strategy to run single staged bilateral hip replacement while addressing the outcomes to achieve swift and cost-effective patient recovery.

AIM

To assess the outcomes and cost effectiveness of bilateral THR (B/L THR) at our tertiary care hospital.

METHODS

Retrospective observational cross- sectional study was undertaken from Jan 2018 to July 2023 to assess the clinical outcomes of patients who underwent single stage B/L THR.

RESULTS

Data of 75 patients were analysed. The mean age was 36 years. Our complication rate was 4.0% including acute coronary syndrome, intra-operative acetabular fracture and paralytic ileus. The re-admission rate was 4%.

CONCLUSION

The choice of sequential or bilateral hip replacement is controversial. While, our study showed that bilateral hip replacement is safe and cost effective. As surgeons, we were careful in patient selection (low American Society of Anesthesiologist score). Though more than 50% of our B/L THR patients were obese [body mass index (BMI) > 25], our outcomes were equivalent to normal BMI patients with lower risk of complication as well as early ambulation. Systemic complication deep vein thrombosis and pulmonary embolism were handled prophylactively by close monitoring, use of mechanical and pharmacological agents along with anticoagulants. Patients who require THR, often require them bilaterally and single stage replacement thus offers early restoration of an individual into their activities of daily living with minimal complications. Our findings support the use of single-stage B/L THR as a viable option for bilateral hip disorders, having favourable outcomes.

Key Words: Bilateral hip replacement; Outcomes; Blood loss; Co-morbidities; Uncemented; Avascular necrosis

Core Tip: Requirements of total hip arthroplasty (THA) is estimated to increase in coming times. Targeted patient selection can be instituted while undertaking THA in order to support favourable patient outcomes.

INTRODUCTION

To date, total hip replacement (THR) is one of the most successful surgical orthopaedic operation and is also titled as “operation of the century”. The oldest record of THR dates back to 1890’s which was presented by Professor Themistocles Glück at the 10^th International Medical Conference where he discussed the use of ivory to replace femoral heads of patients with destroyed hip joints due to tuberculosis[1]. Later in 19’s and 20’s, surgeons experimented with interpositional arthroplasty involving the placement of various tissues - fascia lata, pig bladders submucosa and skin between articulating hip surfaces in arthritic hips[2]. Major breakthrough in hip arthroplasty was achieved time to time from 1980’s onwards. Now, the modern hip arthroplasty consists of multiple cemented and uncemented stems based on the lessons learned from the previous surgeons who performed arthroplasty using different materials[3]. During the last few years, hip arthroplasty has become less invasive, more resistant to wear and tear, more compatible to the hip surfaces. Newer materials have reduced the rate of intra-operative and post- operative complication, reduced the post-operative pain, enhanced early mobilization and integration into activities of daily living[4]. With the growing requirement of bilateral hip replacement due to increasing degenerative hip disease, a surgeon’s main goal is to restore patient’s mobility to maximum and reduce the risk of perioperative complications. In 1976, Ritter and Randolph[5] performed the first detailed study of the functional outcome of single staged bilateral (B/L) THR and since then there here has been an ongoing discussion regarding the advantages and disadvantages of one-stage vs two-stage procedures. So far, many studies have discussed the choice of surgery with patient stratification but it still remains to be controversial. Few studies have suggested shorter rehabilitation, cost-effectiveness, reduced length of stay, reduced repeated anaesthesia exposure etc.[6]. While, some studies have suggested higher risk of complications like deep vein thrombosis and pulmonary embolism in single staged B/L THR vs two staged THR[7]. Also, increased blood loss and transfusion rates have also been suggested by few authors[8]. To our knowledge there are limited studies from Indian sub-continent in this regards, and thus the purpose of this study was to assess the clinical outcomes of the patient undergoing B/L THR at our centre. Furthermore, our secondary objective was to determine the rate of readmission, need for revision surgery after primary B/L THR and the cost effectiveness of the surgery. We hypothesized that there is no difference in outcomes between single staged and two staged B/L THR with the right patient selection.

MATERIALS AND METHODS

A retrospective cross-sectional study was performed at our tertiary health care centre from Jan 2018 to July 2023 to assess the clinical outcomes of patients who underwent single stage B/L THR. The selected inclusion criteria were patients who underwent single stage B/L THR at the centre. Comprehensive data collection included demographics, aetiology, co-morbidities, body mass index (BMI), pre-operative and post-operative haemoglobin, type of surgery, blood loss, blood transfusion, complication, cost of surgery, approach of the surgery, cost of implant, length of hospital stay, American Society of Anesthesiologist (ASA) scores etc.(Table 1). Each patient had been taken for pre-operation X-ray before the surgical intervention where the etiologic of hip disease was confirmed & a post-operation X-ray was also undertaken for each patient in order to assess the status of implant (Figure 1). Total of 83 patients were identified where 75 patients were included in the study after handling the missing data. The surgery was performed by a single senior surgeon using the standard posterior approach in the lateral decubitus position. All details were collected from patients' charts. Patient who underwent resurfacing procedure and Unilateral (either left or right) THR were excluded from the study. The first operation was performed on the more affected/symptomatic hip. Combined spinal and epidural anesthesia was used for all the surgeries.

Figure 1 Pre-operation and post-operation X-rays. A: Pre-operation X-ray; B: Post-operation X-ray.

Table 1 American Society of Anesthesiologist grade of patients (n = 75).

	n	%
Low risk
ASA 1	27	36.0
ASA 2	45	60.0
High risk
ASA 3	3	4.0

ASA: American Society of Anesthesiologist.

The type of surgery was dependent on the proximal femur anatomy and the quality of the bone stalk using the Dorr’s classification. Patients with adequate bone stalk and narrow medullary canal underwent uncemented THR. Patient’s hip with stovepipe- shaped medullary canal underwent cemented THR. Our standardized physiotherapy protocol was followed for rehabilitation. Patients were made be ambulate as per pain tolerance. Patients were discharged upon ambulation across the corridor of 30 meters and on lower drug requirement for pain management. Descriptive data was presented as number of subjects, percentage, mean with Standard Deviation, medians, minimum and maximum. The statistical analysis was reported using summary tables, listings, and figures. In general, for categorical variables the number and percentage of subjects within each category of the parameter were presented. For continuous variables, the number of subjects, mean ± SD values were presented. Demographic measurements were summarized descriptively by treatment. Summary statistics were provided for all the collected parameters, including mean ± SD for continuous variables. The categorical variables were presented with frequency and percentages.

RESULTS

The mean age was 36 years (n = 55, 73% men; Figure 2A) and mean BMI was 26.78 kg/m²; Figure 2B). The 60% (n = 45) patients have ASA score of 2 (Table 1). The most common diagnosis was avascular necrosis (n = 59, 78.67%), followed by developmental dysplasia (n = 30, 8%), osteoarthritis (n = 6, 8%) and ankylosing spondylitis (n = 4, 5.33%; Table 2). The 29.3% were current smokers (Figure 2C). The 36% had co-morbidities (n = 27; Table 3) and the most common co-morbidity was asthma. Steroid was used by 6.7% of patients. Mean length of stay was 2.8 days and the mean ambulation days was 1.3 days (Table 4). The 61.3% patients underwent B/L uncemented THR, 26.7% patients underwent hybrid, 12% patients underwent cemented replacement, and 97% patients underwent replacement using the posterior approach (Table 5). The mean blood loss was 1015 mL. The 72% received blood transfusion with a mean of 1 unit and almost 1/3 required no blood transfusion (Table 6). The 97% had no complications. Our complication rate was 4% including acute coronary syndrome, intra-operative acetabular fracture and paralytic ileus. The mean length of stay in patients with complication was 4.33 days (P = 0.007) and these patients stayed longer than patients without complications. The re-admission rate was 2.6% (n = 2), including periprosthetic fracture of right femur and cup loosening. The study showed not association of age, gender, comorbidities, ASA score, BMI, type of surgery, type of implant with the occurrence of complications in our population. The mean cost of surgery was 5983.29 USD and the implant costed 1821.53 USD in B/L THR. While, in patients with complications the mean cost of surgery was higher (P = 0.04) and the implant cost remained unaffected.

Figure 2 Statistics of patient age body mass index categories and smoking status (n = 75). A: Age distribution; B: Body mass index categories; C: Smoking status.

Table 2 Diagnosis of patients in males and females (n = 75).

Diagnosis	Male (n = 55)		Female (n = 20)		Total (n = 75)
	n	%	n	%	n	%
Avascular necrosis	48	87.27	11	55.00	59	78.67
Developmental dysplasia	0	0.00	6	30.00	6	8.00
Ankylosing spondylitis	3	5.45	1	5.00	4	5.33
Osteoarthritis	4	7.27	2	10.00	6	8.00

Table 3 History of comorbid condition in patients (n = 75).

Comorbidity details	n	%
Asthma	9	12.00
Bronchitis	6	8.00
COPD	1	1.33
COVID	6	8.00
Crohn’s disease	1	1.33
DM	1	1.33
HTN	5	6.67
Hypothroidism	1	1.33
KML	1	1.33
Liver issues	1	1.33
Pancreatitis	1	1.33
Psoriasis	1	1.33
RA	1	1.33
Sinitis	1	1.33
Skin allergy	2	2.67
Steriod use	1	1.33
Total number of co-morbidities	39	89.33
Total number of patients with co-morbidities	27	36.00

COPD: Chronic obstructive pulmonary disease; COVID: Coronavirus disease; DM: Diabetes mellitus; HTN: Hypertension; KML: Kupffer cell-mediated inflammation; RA: RA: Rheumatoid arthritis.

Table 4 Length of hospital stay and ambulatory status with percentiles (n = 75).

	n	Mean	Median	SD	Min	Max	Percentiles
							25	50	75
Length of stay	75	2.84	3.00	0.99	1	6	2	3	3
Time to ambulation	75	1.35	1.00	0.73	1	4	1	1	1

Table 5 Types of surgeries (n = 75).

Types of surgery	n	%
Surgery type
B/L cemented THR	9	12.0
B/L uncemented THR	46	61.3
B/L hybrid hip	20	26.67
Surgical approach
Posterior approach	73	97.3
Direct acetabular approach	1	1.3
Post (B/L adductor tenotomy)	1	1.3

B/L: Bilateral; THR: Total hip replacement.

Table 6 Blood loss and blood transfusion in patients (n = 75).

	n	Mean	Median	SD	Min	Max	%
Hb (gm/dL)
Pre-operative	75	14.20	14.30	1.95	7	18
Post-operative	75	10.49	10.50	1.57	7	15
Intra-operative blood loss (mL)	75	1015.33	1000.00	373.08	300	2000
Blood transfusion (unit)
No blood transfusion	21						28.0
1	33						44.0
2	17						22.7
3	4						5.3
Blood transfusion given (number of patients)	54						72.0

DISCUSSION

Most patients who require hip replacement require it bilaterally and these cases are increasing at rampant pace. THA is now considered as the “operation of the century” where patients experience normal feeling joint or “forgotten joint”[9].

To date, there is no consensus on the surgery of choice (single staged or double staged) in patients with hip disorders. Commonly, concerns with B/L THR arises are that of increased peri-operative complication (increased blood loss, increased blood transfusion) followed by post-operative complications like deep vein thrombosis, pulmonary embolism and periarticular heterotropic ossification[10]. While most surgeons prefer two staged hip replacements, effective outcomes can be obtained if the patient selection is done wisely. Our patient selection was conducted with ASA of lower risk and younger age group and thorough monitoring of systemic complications and its prophylactic handling was undertaken. In a large United States nationwide cohort study by Morton et al[11], a total of 97804 patients with unilateral and 587 patients who underwent bilateral THA data was analysed. Here, patients undergoing bilateral hip replacement were younger (57.3 vs 64.6 years, P < 0.001), had lower BMI (29.2 vs 30.2, P < 0.001), while in our study the mean age of B/L THR was 36 years (n = 55, 73% men) with a mean BMI of 26.7 kg/m² (overweight category). Current literature suggests that BMI > 40 kg/m² is the threshold at which most complications occur including infections, higher rate of re-admission etc.[12]. However, there are mixed suggestions with regards to increased complications with increasing BMI. Kumar et al[13] reported that most common causes of hip disorders were non traumatic avascular necrosis followed by post-traumatic sequelae, primary osteoarthritis and inflammatory pathologies. In comparison to our study, most common diagnosis was Avascular necrosis (n = 59, 78.67%), followed by developmental dysplasia (n = 30, 8%), osteoarthritis (n = 6, 8%) and ankylosing spondylitis (n = 4, 5.33%). Many studies have previously shown that pain and satisfaction after THA are affected by preoperative comorbidities[14]. In a study by Lan et al[15], it was seen that as the age advanced individuals had higher co-morbidities had reduced physical function, increased pain, experienced longer pre-op waiting time, took longer to recover, had higher rates of complications, higher 30-day readmission rate and mortality after THA. While, in our study the population consisted of much younger individuals than most studies and experienced favourable outcomes with reduced average hospital stay, early ambulation, fewer complications and reduced rate of re-admission thereby leading to cost effectiveness of the surgery. Blood loss is a common surgical risk after any major surgery and it is estimated that the average blood loss after THA is 1188-1651 mL[16]. Knowing about the general blood loss helps in appropriate patient counselling, assessing future transfusion requirements and also predicting timely discharge. It has been stated that approximately 10% of all packed red cell transfusions occur within orthopaedics, and almost 40% of these are used in joint replacement[17]. It has also been stated that spine and arthroplasty surgeries have higher rate of transfusion, about 20%-70% THA patients are transfused and most transfusions falling in the mid-range[18]. In our study, the mean blood loss was 1015 mL and 72% received blood transfusion with a mean of 1 unit and almost 1/3 required no blood transfusion.

CONCLUSION

Requirements of THA is estimated to increase in coming times. Bilateral total hip recipients in our study were much younger, had fewer co-morbidities with lower ASA (through careful patient selection). These factors had favourable outcomes in patient recovery, rate of ambulation, blood transfusion, cost effectiveness of the surgery as well as in reduced rate of readmission and complications. With this information, targeted patient selection can be instituted while undertaking THA. Our findings support the use of single-stage B/L THR as a viable option for bilateral hip disorders, having favourable outcomes.

ACKNOWLEDGEMENTS

We thank Chaitanya Sharma for his support in reviewing the manuscript.