Trial Outcomes & Findings for A Trial Comparing Mini-posterior Approach and Direct Anterior Approach (NCT NCT01024309)

NCT ID: NCT01024309

Last Updated: 2014-10-30

Results Overview

The primary early functional endpoint is the difference between groups in the postoperative days that patients require any assistive devices for ambulation. Lower number of days indicate better outcomes.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 66 participants
• Primary outcome timeframe: 6 week
• Results posted on: 2014-10-30

Participant Flow

66 volunteer participants were enrolled during routine clinical practice of the principal investigator between the dates of 12/8/2009 and 10/9/2012.

12 patients withdrew participation prior to randomization

Participant milestones

Measure	Mini-Posterior Approach Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach Direct Anterior surgical approach for total hip arthroplasty
Overall Study STARTED	35	31
Overall Study COMPLETED	27	27
Overall Study NOT COMPLETED	8	4

Reasons for withdrawal

Measure	Mini-Posterior Approach Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach Direct Anterior surgical approach for total hip arthroplasty
Overall Study Physician Decision	4	0
Overall Study Withdrawal by Subject	4	4

Baseline Characteristics

A Trial Comparing Mini-posterior Approach and Direct Anterior Approach

Baseline characteristics by cohort

Measure	Mini-Posterior Approach n=35 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=31 Participants Direct Anterior surgical approach for total hip arthroplasty	Total n=66 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	18 Participants n=5 Participants	17 Participants n=7 Participants	35 Participants n=5 Participants
Age, Categorical >=65 years	17 Participants n=5 Participants	14 Participants n=7 Participants	31 Participants n=5 Participants
Age, Continuous	64.2 years STANDARD_DEVIATION 9.4 • n=5 Participants	63.4 years STANDARD_DEVIATION 8.6 • n=7 Participants	63.8 years STANDARD_DEVIATION 9.0 • n=5 Participants
Sex: Female, Male Female	18 Participants n=5 Participants	16 Participants n=7 Participants	34 Participants n=5 Participants
Sex: Female, Male Male	17 Participants n=5 Participants	15 Participants n=7 Participants	32 Participants n=5 Participants
Region of Enrollment United States	35 participants n=5 Participants	31 participants n=7 Participants	66 participants n=5 Participants

PRIMARY outcome

Timeframe: 6 week

Population: A total of 54 participants returned for follow-up at 6 weeks. The remaining patients did not return to the clinic for follow-up at 6 weeks.

The primary early functional endpoint is the difference between groups in the postoperative days that patients require any assistive devices for ambulation. Lower number of days indicate better outcomes.

Outcome measures

Measure	Mini-Posterior Approach n=27 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=27 Participants Direct Anterior surgical approach for total hip arthroplasty
Number of Days for Discontinue Assistive Devices	28 days Interval 20.0 to 42.0	22 days Interval 12.0 to 30.0

SECONDARY outcome

Timeframe: 3 week

Population: A total of 53 participants returned for follow-up at 3 weeks. The remaining patients did not return to the clinic for follow-up at 3 weeks.

The postoperative rate of improvement in functional outcome, measured by the Harris Hip Score (HHS). The HHS was developed to assess the results of hip surgery and is intended to evaluate various hip disabilities and methods of treatment in an adult population. The domains covered are pain, function, absence of deformity, and range of motion. The function domain consists of daily activities (stair use, using public transportation, sitting, and managing shoes and socks) and gait (limp, support needed, and walking distance). Deformity takes into account hip flexion, adduction, internal rotation, and extremity length discrepancy. Range of motion measures hip flexion, abduction, external and internal rotation, and adduction. There are 10 items, which are summed to create a score out of 100. The score has a range of 0 (wost possible outcome) to 100 (best possible outcome) covering pain (0-44 points), function (0-47 points), absence of deformity (4 points), and range of motion (5 points).

Outcome measures

Measure	Mini-Posterior Approach n=27 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=26 Participants Direct Anterior surgical approach for total hip arthroplasty
Harris Hip Score	81 units on a scale Interval 74.0 to 89.0	86.5 units on a scale Interval 77.0 to 95.0

SECONDARY outcome

Timeframe: 3 week

Population: A total of 53 participants returned for follow-up at 3 weeks. The remaining patients did not return to the clinic for follow-up at 3 weeks.

Total score from the Western Ontario and McMaster Universities Arthritis Index (WOMAC), which is a widely used set of standardized questionnaires used to evaluate the condition of patients with osteoarthritis of the knee and hip, including pain, stiffness, and physical functioning of the joints. WOMAC measures five items for pain (score range 0-20), two for stiffness (range 0-8), and 17 for functional limitation (range 0-68). Physical functioning questions cover everyday activities such as stair use, standing up from a sitting or lying position, standing, bending, walking, getting in/out of a car, shopping, putting on or taking off socks, lying in bed, getting in or out of a bath, sitting, and heavy and light household duties. It produces three subscale scores (pain, stiffness, and physical function) and a total score. These scores are transformed into a scale of 0 (worst possible outcome) to 100 (best possible outcome) for ease of interpretation and comparison with other studies.

Outcome measures

Measure	Mini-Posterior Approach n=27 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=26 Participants Direct Anterior surgical approach for total hip arthroplasty
Western Ontario and McMaster Universities Arthritis Index (WOMAC)	91.48 units on a scale Interval 85.01 to 96.19	87.20 units on a scale Interval 74.92 to 92.03

SECONDARY outcome

Timeframe: 6 wk

Population: A total of 54 participants returned for follow-up at 6 weeks. The remaining patients did not return to the clinic for follow-up at 6 weeks.

Abduction angle is a radiographic measure of implant position. 40 degrees of abduction is optimal. 30-50 degrees of anteversion indicates correct placement of prosthetic joint. Values closer to 40 degrees indicate better placement.

Outcome measures

Measure	Mini-Posterior Approach n=27 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=27 Participants Direct Anterior surgical approach for total hip arthroplasty
Abduction Angle	40 degrees Interval 36.0 to 42.0	38 degrees Interval 36.0 to 41.0

SECONDARY outcome

Timeframe: 6 week

Population: A total of 54 participants returned for follow-up at 6 weeks. The remaining patients did not return to the clinic for follow-up at 6 weeks.

Anteversion angle is a radiographic measure of implant position. 35 degrees of anteversion is optimal. 25-45 degrees of anteversion indicates correct placement of prosthetic joint. Values closer to 35 degrees indicate better placement.

Outcome measures

Measure	Mini-Posterior Approach n=27 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=27 Participants Direct Anterior surgical approach for total hip arthroplasty
Anteversion Angle	29 degrees Interval 26.0 to 32.0	26 degrees Interval 24.0 to 28.0

SECONDARY outcome

Timeframe: 6 week

Population: 54 participants returned for follow-up at 6 weeks. A total of 5 participants did not complete the Harris Hip Score instrument in its entirety at this appointment and, thus, were excluded from the analysis. The remaining patients did not return to the clinic for follow-up at 6 weeks.

The postoperative rate of improvement in functional outcome, measured by the Harris Hip Score (HHS). The HHS was developed to assess the results of hip surgery and is intended to evaluate various hip disabilities and methods of treatment in an adult population. The domains covered are pain, function, absence of deformity, and range of motion. The function domain consists of daily activities (stair use, using public transportation, sitting, and managing shoes and socks) and gait (limp, support needed, and walking distance). Deformity takes into account hip flexion, adduction, internal rotation, and extremity length discrepancy. Range of motion measures hip flexion, abduction, external and internal rotation, and adduction. There are 10 items, which are summed to create a score out of 100. The score has a range of 0 (wost possible outcome) to 100 (best possible outcome) covering pain (0-44 points), function (0-47 points), absence of deformity (4 points), and range of motion (5 points).

Outcome measures

Measure	Mini-Posterior Approach n=26 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=23 Participants Direct Anterior surgical approach for total hip arthroplasty
Harris Hip Score	93 units on a scale Interval 89.0 to 98.0	97 units on a scale Interval 90.0 to 98.0

SECONDARY outcome

Timeframe: 6 week

Population: A total of 54 participants returned for follow-up at 6 weeks. 3 participants did not complete the WOMAC in its entirety at this appointment and, thus, were excluded from the analysis. The remaining patients did not return to the clinic for follow-up at 6 weeks.

Total score from the Western Ontario and McMaster Universities Arthritis Index (WOMAC), which is a widely used set of standardized questionnaires used to evaluate the condition of patients with osteoarthritis of the knee and hip, including pain, stiffness, and physical functioning of the joints. WOMAC measures five items for pain (score range 0-20), two for stiffness (range 0-8), and 17 for functional limitation (range 0-68). Physical functioning questions cover everyday activities such as stair use, standing up from a sitting or lying position, standing, bending, walking, getting in/out of a car, shopping, putting on or taking off socks, lying in bed, getting in or out of a bath, sitting, and heavy and light household duties. It produces three subscale scores (pain, stiffness, and physical function) and a total score. These scores are transformed into a scale of 0 (worst possible outcome) to 100 (best possible outcome) for ease of interpretation and comparison with other studies.

Outcome measures

Measure	Mini-Posterior Approach n=25 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=26 Participants Direct Anterior surgical approach for total hip arthroplasty
WOMAC	95.72 units on a scale Interval 91.48 to 98.92	95.41 units on a scale Interval 87.83 to 97.37

SECONDARY outcome

Timeframe: 12 month

Population: A total of 37 participants returned for follow-up at 12 months. The remaining patients did not return to the clinic for follow-up at 12 months.

The postoperative rate of improvement in functional outcome, measured by the Harris Hip Score (HHS). The HHS was developed to assess the results of hip surgery and is intended to evaluate various hip disabilities and methods of treatment in an adult population. The domains covered are pain, function, absence of deformity, and range of motion. The function domain consists of daily activities (stair use, using public transportation, sitting, and managing shoes and socks) and gait (limp, support needed, and walking distance). Deformity takes into account hip flexion, adduction, internal rotation, and extremity length discrepancy. Range of motion measures hip flexion, abduction, external and internal rotation, and adduction. There are 10 items, which are summed to create a score out of 100. The score has a range of 0 (wost possible outcome) to 100 (best possible outcome) covering pain (0-44 points), function (0-47 points), absence of deformity (4 points), and range of motion (5 points).

Outcome measures

Measure	Mini-Posterior Approach n=20 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=17 Participants Direct Anterior surgical approach for total hip arthroplasty
Harris Hip Score	97.5 units on a scale Interval 87.0 to 100.0	98 units on a scale Interval 94.0 to 100.0

SECONDARY outcome

Timeframe: 12 month

Population: A total of 37 participants returned for follow-up at 12 months. The remaining patients did not return to the clinic for follow-up at 12 months.

Total score from the Western Ontario and McMaster Universities Arthritis Index (WOMAC), which is a widely used set of standardized questionnaires used to evaluate the condition of patients with osteoarthritis of the knee and hip, including pain, stiffness, and physical functioning of the joints. WOMAC measures five items for pain (score range 0-20), two for stiffness (range 0-8), and 17 for functional limitation (range 0-68). Physical functioning questions cover everyday activities such as stair use, standing up from a sitting or lying position, standing, bending, walking, getting in/out of a car, shopping, putting on or taking off socks, lying in bed, getting in or out of a bath, sitting, and heavy and light household duties. It produces three subscale scores (pain, stiffness, and physical function) and a total score. These scores are transformed into a scale of 0 (worst possible outcome) to 100 (best possible outcome) for ease of interpretation and comparison with other studies.

Outcome measures

Measure	Mini-Posterior Approach n=20 Participants Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=17 Participants Direct Anterior surgical approach for total hip arthroplasty
WOMAC	97.37 units on a scale Interval 88.84 to 100.0	97.37 units on a scale Interval 92.07 to 99.46

Adverse Events

Mini-Posterior Approach

Serious events: 3 serious events

Other events: 1 other events

Deaths: 0 deaths

Direct Anterior Approach

Serious events: 1 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Measure	Mini-Posterior Approach n=27 participants at risk Mini-Posterior surgical approach for total hip arthroplasty: Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=27 participants at risk Direct Anterior surgical approach for total hip arthroplasty: Direct Anterior surgical approach for total hip arthroplasty
Cardiac disorders Chest pain and tightness	3.7% 1/27 • Number of events 1	0.00% 0/27
Injury, poisoning and procedural complications Medication Overdose	0.00% 0/27	3.7% 1/27 • Number of events 1
Injury, poisoning and procedural complications Superficial hematoma	3.7% 1/27 • Number of events 1	0.00% 0/27
Gastrointestinal disorders Gallstone	3.7% 1/27 • Number of events 1	0.00% 0/27

Other adverse events

Measure	Mini-Posterior Approach n=27 participants at risk Mini-Posterior surgical approach for total hip arthroplasty: Mini-Posterior surgical approach for total hip arthroplasty	Direct Anterior Approach n=27 participants at risk Direct Anterior surgical approach for total hip arthroplasty: Direct Anterior surgical approach for total hip arthroplasty
Musculoskeletal and connective tissue disorders Calcar bone fracture	3.7% 1/27 • Number of events 1	3.7% 1/27 • Number of events 1
Metabolism and nutrition disorders Dehydration and gastroenteritis	3.7% 1/27 • Number of events 1	0.00% 0/27
Injury, poisoning and procedural complications Surgical incision complication	0.00% 0/27	3.7% 1/27 • Number of events 1

Additional Information

Dr. Susan Odum

OrthoCarolina Research Institute

Phone: 704.323.2265

Email: Susan.Odum@OrthoCarolina.com

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place