The Clinical Outcomes After Direct Anterior Approach and Microposterior Approach for Total Hip Arthroplasty

Total Hip Arthroplasty Clinical Trial

Official title:

The Clinical Outcomes After Mini-incision Direct Anterior Approach and Microposterior Approach for Total Hip Arthroplasty

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT03210844
• Other study ID #: 201511088RINB
• Status: Active, not recruiting
• Phase: N/A
• First received: June 25, 2017
• Last updated: July 6, 2017
• Start date: October 1, 2013
• Est. completion date: July 30, 2017

Study information

• Verified date: June 2017
• Source: National Taiwan University Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Background The direct anterior approach (DAA) and micro-posterior approach (micro-PA) for total hip arthroplasty (THA) become popular approaches due to their fast recovery and good clinical outcomes. However, little is known if DAA is superior to micro-PA in implant positioning and functional outcomes for THA patients.

Methods The investigators conducted a non-randomized comparative study to compare component positioning and clinical outcomes of the consecutive unilateral primary THA patients operated with DAA techniques and that of those operated with micro-PA techniques by a single surgeon. The investigators used DAA techniques with standard operation table and micro-PA techniques featuring indirect-contracture-releasing capsulotomy, preservation of short external rotators except piriformis and conjoint tendon, and tendon-to-bone capsulotendinous repair. The investigators used propensity-score matching analysis to compare the postoperative THA component positioning and clinical outcomes in DAA and micro-PA groups.

Description:

The direct anterior approach (DAA) has become a popular approach for total hip arthroplasty (THA) recently because of its atraumatic intermuscular plane, less tissue damage, and faster recovery. Studies comparing DAA with standard lateral or posterior approach showed DAA THAs have better results. These better results of DAA included possible lower dislocation rate, less perioperative pain, shorter length of hospital stay, and better implant position. However, DAA is a technic-demanding approach which needs a longer learning curve, and may endanger lateral femoral cutaneous nerve. DAA may also incurs a higher complication rates in obese patients than other approaches. Similarly, the mini-incision posterior approach (mini-PA) has most of the above-mentioned advantages of DAA except atraumatic intermuscular plane. Comparing with standard posterior approach, the mini-PA resulted in better function scores, shorter length of hospital stay, reduced blood loss, comparable radiographic outcome and complication rates. More recently, the micro-posterior approach (micro-PA), which evolves from mini-PA but preserves short external rotators of the hip except for the piriformis or conjoined tendon and includes all advantages of mini-PA, has been introduced into clinical practice and gained excellent clinical results.

Both DAA and micro-PA have their own advantages and disadvantages. Because of the fast recovery, both DAA and mini-PA were successfully used in outpatient THA. Furthermore, supine positioning during DAA facilitates the use intraoperative fluoroscopy to improve component positioning, while mini-PA and micro-PA utilize lateral decubitus position and achieve the safe zone of Lewinnek in only 60% of cases for cup positioning. In the learning curve of DAA, despite of the muscle-sparing advantage, there may be high early revision rate of THA. Therefore, both DAA and micro-PA have their own enthusiasts. To our knowledge, there were no studies comparing the results of DAA THAs with micro-PA THAs. Thus The investigators conducted a single-surgeon propensity-score matching study to compare these two approaches. Our hypothesis is that DAA THAs may have better results than micro-PA THAs in component positions and other clinical outcomes. The purpose of this study were to compare (1) the radiographic component positions, (2) the clinical outcomes, such as length of hospital stay, operative time, blood loss, perioperative pain scale, dislocation rates, and functional scores between DAA and micro-PA for THA.

Methods The investigators conducted a non-randomized comparative study to compare component positioning and clinical outcomes of the unilateral primary THA patients with DAA techniques and those with micro-PA techniques. The investigators received approval from institutional review board in National Taiwan University Hospital. The investigators recruited consecutive patients receiving unilateral primary THAs performed by a single surgeon (the senior author) between October 2013 and September 2014. The eligibility criteria were patients with unilateral hip arthritis indicated for THA. The excluding criteria were patients with previous THAs or patients indicated for revision THAs. A total number of 141 patients were recruited. Twenty-six of the patients underwent THAs with DAA and 115 of the patients underwent THAs with micro-PA. The patient demographics was shown in table 1. All the patients were regularly follow-up at least 2 year in out-patient clinics. The investigators used Trilogy acetabular cup system and ML-taper femoral components (Zimmer Inc., Warsaw, IN, United States) in all patients.

Perioperative protocol and discharge criteria Pre-operative digital templating was performed by the senior with AGFA IMPAX Orthopaedic Tools (Agfa Healthcare, Mortsel, Belgium) for every patient. Multimodal analgesia protocol including preoperative, intraoperative and postoperative medications (pregabalin, tramadol, acetaminophen, and celecoxib) was used in every patient. Intra-operatively, the patients received local infiltration analgesia with periarticular injection of diluted ketorolac and levobupivacaine solution. Additional intramuscular morphine was given for pain relief. The discharge criteria included (1) ambulation for 30 meters with assistive devices, (2) the ability to go up and down stairs with assistive devices, and (3) no need for intravenous or intramuscular analgesics.

Clinical outcomes Estimated blood loss, operation time and length of hospital stay were obtained from the electronic medical records. The patients' hemoglobin level was checked routinely on the day before operation and on the first and second post-operative days. The investigators also calculated the decreased amount of hemoglobin level as a more objective parameter for blood loss. Visual analogue scale (VAS) was recorded 4 times a day by nurse practitioners during hospitalization. The mean VAS on the first, second and third post-operative days were used for analysis respectively. Besides, the morphine dosage during hospitalization also served as another parameter of pain intensity. In addition to chart review, Harris hip score, Oxford hip score (OHS), and EQ5d scores were obtained for outcome evaluation at 3 months, 6 months, and 2 years after operation.

Radiographic parameters The stem alignment, acetabular cup abduction, anteversion angles and leg-length discrepancy were measured on digital anteroposterior (AP) pelvic radiographs. The radiographs were all obtained using a standardized technique with supine position, leg internally rotated and x-ray beam centered on pubic symphysis. For stem alignment, the investigators obtained proximal femoral axis, which was the line connecting centers of femoral canal at the levels of stem tip and lesser trochanter, and the femoral stem axis, which was the line connecting centers of femoral stem at levels of 2 centimeters and 5 centimeters proximal to the stem tip. The angle between proximal femoral axis and femoral stem axis was measured and analyzed as the stem alignment. The cup anteversion angle and abduction angle were means measured using AGFA IMPAX Orthopaedic Tool (Agfa Healthcare, Mortsel, Belgium). The leg-length discrepancy was the distance between the two lines from each lesser trochanter parallel to the inter-teardrop line.

Statistical Analysis With presumed achieved proportion of safe zone of Lewinnek in DAA and mini-PA, a minimum of 21 patients in each group were required, with an assumed two-sided alpha level of 5% and a power of 80%. Using body mass index (BMI), age and gender as covariates, 1:1 (DAA : micro-PA) propensity score matching was done. All the following analysis were calculated before and after propensity-score matching. The investigators used Mann-Whitney U test for comparison of continuous data and Chi-square test for categorical data. P < 0.05 was considered statistically significant. The software for analysis was STATA (StataCorp LP, Texas, USA).

Source of Funding Funding source did not play any role in this investigation.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 141
• Est. completion date: July 30, 2017
• Est. primary completion date: July 30, 2017
• Accepts healthy volunteers: No
• Gender: All
• Age group: 20 Years to 100 Years
• Eligibility: patients with unilateral hip arthritis indicated for THA

Related Conditions & MeSH terms

• Total Hip Arthroplasty

Intervention

Procedure:
• Surgical approaches of total hip arthroplasty
Surgical approaches of total hip arthroplasty

Locations

Country	Name	City	State
Taiwan	National Taiwan University Hospital	Taipei

Sponsors (1)

Lead Sponsor	Collaborator
National Taiwan University Hospital

Country where clinical trial is conducted

Taiwan, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Radiographic component positions - femoral alignment	femoral alignment - to measure the angle between the stem axis and proximal femur axis on X ray 3. Cup inclination angle	Postoperative 2 year
Primary	Radiographic component positions - Cup anteversion angle	to measure the cup anteversio angle on the X ray	Postoperative 2 year
Primary	Radiographic component positions - Cup inclination angle	to measure the cup inclination angle on the X ray	Postoperative 2 year
Secondary	Leg length control	The difference of the distance of bilateral lesser trochanter to the inter-teardrop line	Postoperative 2 year
Secondary	Perioperative pain intensity	The record of visual analog pain scale on postoperative 1st, 2nd and 3rd days	postoperative 1st, 2nd and 3rd days
Secondary	Morphine usage	The morphine dosage which was needed on postoperative 1st, 2nd and 3rd days	postoperative 1st, 2nd and 3rd days
Secondary	Functional outcomes - Oxford hip score	The record of Oxford hip score	Postoperative 2 year
Secondary	Functional outcomes - EQ5D score	The record of EQ5D score	Postoperative 2 year
Secondary	Functional outcomes - Harris hip score	The record of Harris hip score	Postoperative 2 year
Secondary	Length of hospital day	The record of admission date and discharge date	Postoperative 2 week
Secondary	Dislocation rate	We reviewed the image and medical record and asked the patients for dislocation rate	Postoperative 2 year
Secondary	Operative blood loss	The record of operation note for blood loss	1 day (operation day)
Secondary	Perioperative blood loss	We reviewed the hemoglobin level one day before the operation day and on the postoperative day 1. The hemoglobin difference was the parameter for perioperative blood loss.	3 day (from the day before operation to postoperative day 1)