MASTERS-D: A Prospective, Multicenter Observational Study on MAST™ (Minimal Access Spinal Technologies) Fusion Procedures for the Treatment of the Degenerative Lumbar Spine

• Sponsor: Medtronic Spinal and Biologics (Industry)
• Overall Status: Completed
• CT.gov ID: NCT01143324
• Collaborator: (none)
• Enrollment: 255
• Locations: 19
• Duration (Months): 38
• Patients Per Site: 13.4
• Patients Per Site Per Month: 0.4

Study Details

Study Description

Brief Summary

The aim of the study is to observe and document surgical practice and evaluate patients' outcomes following a MAST™ single or double level instrumented fusion procedure using PLIF (Posterior Lumbar Interbody Fusion) or TLIF (Transforaminal Lumbar Interbody Fusion) techniques for the treatment of the degenerative lumbar spine in a "real-world" patient population.

Condition or Disease	Intervention/Treatment	Phase
Degenerative Lumbar Spine Causing Back and/or Leg Pain; Lumbar Spine Degeneration	Device: MAST™ procedure

Detailed Description

Instrumented lumbar fusion is usually done through an open procedure which involves an excessive intraoperative dissection and retraction of the paraspinal musculature leading, in a short term basis, to a prolonged recovery time from the surgery. This open approach is frequently associated with significant blood loss and need of transfusion, produces the majority of the perioperative pain, increases hospital stay and the chances of infection and delays the return to normal activities and to work. In a long term basis, the open procedure leads to denervation, atrophy and loss of the muscles independent function, resulting in an increased risk of "fusion disease", a term that has been coined to describe its occurrence.

The minimally invasive spinal surgery was developed as a potential solution to the above-mentioned problems by reducing the amount of iatrogenic soft tissue injury while reaching the same traditional goals of the open procedures. Besides minimizing the long-term effects of exposure-related muscle injury, minimally invasive lumbar fusion techniques hold the promise of immediate short-term advantages. Patients undergoing minimally invasive procedures are reported to recover earlier from the surgery. Shorter time to first ambulation, less pain medication consumption, less blood loss, less required transfusion, shorter hospital stay and earlier return to work are generally associated with the minimally invasive procedure as compared to the standard open surgeries. The minimally invasive access requires a surgical corridor targeted on the disease which is accomplished by using a series of tubular muscle dilators allowing a clear intraoperative visualization to perform these procedures together with the parallel use of image guided percutaneous insertion of pedicle screws and instrumentation.

The purpose of this study is to observe and document surgical practice and evaluate patients' outcomes following a MAST™ single or double level instrumented fusion procedure using PLIF or TLIF techniques for the treatment of the degenerative lumbar spine in a "real-world" patient population.

Study Design

• Study Type: Observational
• Actual Enrollment: 255 participants
• Observational Model: Case-Only
• Time Perspective: Prospective
• Official Title: A Prospective, Multicenter Observational Study on MAST™ (Minimal Access Spinal Technologies) Fusion Procedures for the Treatment of the Degenerative Lumbar Spine (MASTERS-D)
• Study Start Date: Jun 1, 2010
• Actual Primary Completion Date: May 1, 2013
• Actual Study Completion Date: Aug 1, 2013

Arms and Interventions

Arm	Intervention/Treatment
MAST™ procedure	Device: MAST™ procedure; Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.

Outcome Measures

Primary Outcome Measures

1. Time From Surgery to First Ambulation. [From date of Surgery to date of First ambulation, assessed up to hospital discharge.]

   The primary objective of the study is to access the short term recovery (from surgery to hospital discharge) since the minimally invasive lumbar fusion techniques are expected to be associated with immediate short-term benefits. Patients undergoing minimally invasive procedures are reported to recover earlier from surgery particularly with a shorter time to first ambulation and shorter discharge as compared to the standard open procedures. Outcome measure timeframe for time from surgery to first ambulation is assessed up to hospital discharge as pts are all ambulated before discharge from the hospital.

2. Time to Surgery Recovery Day. [From date of surgery until date of surgery recovery day assessed up to hospital discharge.]

   The primary objective of the study is to access the short term recovery (from surgery to discharge) since the minimally invasive lumbar fusion techniques are expected to be associated with immediate short-term benefits. Patients undergoing minimally invasive procedures are reported to recover earlier from surgery particularly with a shorter time to first ambulation and shorter discharge as compared to the standard open procedures. Surgery recovery day is defined as the day when patients fulfils following criteria : patient no longer needs intravenous infusion of analgesic drugs, there are no surgery related complications (AEs) impending discharge of patient, patient no longer needs nursing care. The objective of the surgery recovery day assessment is to collect the day when the patient could be discharged based on his actual clinical condition because the effective day of discharge may be prolonged by factors other than the patient's clinical recovery such as social factors.

Secondary Outcome Measures

1. Back Pain Intensity Visual Analog Scale (VAS) Score as Compared to Baseline. [Baseline, 12 months]

   Relief of Back Pain intensity at 12 months compared to the baseline using the Back Pain Intensity Score assessed on a 10 cm Visual Analog Scale (VAS). The endpoint is the difference between baseline and 12 months of the patient's back-pain intensity score on a Visual Analogue Scale (VAS). A standardized visual analogue scale (0cm-10cm; with 0cm meaning 'no pain' and 10cm meaning 'worst possible pain') was used. Large values of the VAS score represent large degree of pain. Large (negative) change in VAS score (12 months - baseline) represents large relief of pain.

2. Leg Pain Intensity VAS Score as Compared to Baseline [Baseline, 12 months]

   Leg pain intensity (using VAS intensity score) as compared to baseline. Relief of Leg Pain intensity at 12 months compared to the baseline using the Back Pain Intensity Score assessed on a 10 cm Visual Analog Scale (VAS). The endpoint is the difference between baseline and 12 months of the patient's leg-pain intensity score on a Visual Analogue Scale (VAS). A standardized visual analogue scale (0cm-10cm; with 0cm meaning 'no pain' and 10cm meaning 'worst possible pain') was used. Large values of the VAS score represent large degree of pain. Large (negative) change in VAS score (12 months - baseline) represents large relief of pain.

3. EQ-5D Questionnaire (When it is a Routine Practice) as Compared to Baseline. [Baseline, 12 months]

   EQ-5D questionnaire as compared to baseline measurement. EQ-5D Index was calculated based on answers provided in the questionnaire. Applicable to a wide range of health conditions and treatments, the EQ-5D provides a simple descriptive profile and a single index value for health status. The EQ-5D-3L consists of the EQ-5D-3L descriptive system and the EQ visual analogue scale (EQ VAS). The EQ-5D descriptive system comprises 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 3 levels: no problems, some problems, extreme problems. The respondent is asked to indicate his/her health state by ticking in the box against the most appropriate statement in each of the 5 dimensions. EQ VAS records the respondent's self-rated health on a vertical 20 cm VAS where the endpoints are labelled 'Best imaginable health state' at the top and 'Worst imaginable health state' at the bottom, having numeric values of 100 and 0 respectively.

4. Fusion Rate as Assessed by CT Scan or X-Rays, in Those Sites Where This Assessment is Standard of Care. [12 months]

   Fusion rate as assessed by the CT Scan or X-Rays, in those sites where this assessment is standard of care.

5. Number of Patients Who Utilized Rehabilitation Programs [From 6-12 months after the day of surgery]

   The number of patients who utilized rehabilitation programs was documented (when required).

6. Proportion of Patients Needing a Second Intervention at the Treated Level(s) (Reoperation Rates). [From baseline until 12 months]

   Proportion of the patients needing a second intervention at the treated level(s) (reoperation rates).

7. Proportion of Patients Needing Intervention at Adjacent Level(s). [From Baseline until 12 months]

   Proportion of the patients needing intervention at adjacent level(s).

8. Document Change in Pain Medication Consumption Over Time as Compared With Baseline. Baseline. [Baseline, 12 months]

   Document the change in pain medication consumption one year after surgery , as compared with baseline. The endpoint is the number of participants taking pain medication at baseline and number of participants taking pain medication in the week before the 12 months follow up visit.

9. Document Adverse Events Occurrence Throughout the Study. [From Baseline until 12 months]

   Document the Adverse Events occurrence throughout the study. All adverse events have been included regardless visit windowing.

10. ODI Difference 12 Months After the Surgery as Compared to Baseline. [Baseline, 12 months]

    Oswestry Disability Index (ODI) 12 months after the surgery as compared to baseline. The Oswestry Disability Index (ODI) derives from the Oswestry Low Back Pain Questionnaire, it is used to measure disability for low back pain. The index is scored from 0 to 100; 0 meaning 'no disability' and 100 meaning 'maximum disability'.

11. Number of Patients That Returned to Work 12months After the Surgery. [12 months after the surgery]

    Document number of participants that returned to work 12 months after surgery.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

• Patient is >18 years of age (or minimum age as required by local regulations).

• Patient has indication for a single or double level instrumented lumbar fusion for the treatment of the degenerative lumbar spine.

• Patient agrees to participate in the study and is able to sign the Data Release Form/Informed Consent.

• The procedure planned for the patient complies with the labeling of the Devices that may be used in the surgical procedure as described in the section B.2 Device Information.

• Patient is planned to be submitted to the fusion procedure using PLIF or TLIF techniques and to receive a CD HORIZON® Spinal System via a MAST™ approach.

• The patient is willing and is able to cooperate with study procedures and required follow-up visits.

Exclusion Criteria:

• Patient that has already undergone an open lumbar spine surgery other than microdiscectomy.

• Indications for the procedure other than degenerative spine disease like Osteoporotic vertebral fractures, Spine trauma fractures and Spine tumor.

In order to reduce as much as possible bias in this observational study, the study centers should propose the study to all consecutive individuals who meet these in and exclusion criteria to participate in the study in order to comply with the 'real world' population concept. This observational study does not require any specific test or procedure that falls outside a standard surgical procedure and patient follow-up as routinely done in the hospital. Some data was collected only for centers that applied such procedures as standard of care.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Klinikum Amstetten	Amstetten		Austria
2	OLV Ziekenhuis	Aalst		Belgium
3	Spine, Sports Medicine and Orthopedic Surgery	Saint John	New Brunswick	Canada
4	Karvinska Hornicka Nemocnice	Karvina		Czechia
5	Klinikum Kulmbach	Kulmbach	Bayern	Germany
6	Marienhaus Klinikum	Bendorf		Germany
7	Neurochirurgische Universitatsklinik	Freiburg		Germany
8	Universitätsklinikum Magdeburg	Magdeburg		Germany
9	Mediterraneo	Glyfada		Greece
10	The Tel Aviv Sourasky Medical Center	Tel Aviv		Israel
11	Instituto Ortopedici Rizzoli	Bologna		Italy
12	Fatebenefratelli Hospital	Milano		Italy
13	Bergman Clinics	Naarden		Netherlands
14	Franciscus Ziekenhuis Roosendaal	Roosendaal		Netherlands
15	University Clinical Center	Gdansk		Poland
16	Hospital San Joao	Porto		Portugal
17	Ustredna Vojenska Nemocnica SNP	Ruzomberok		Slovakia
18	Hospital Clinic De Barcelona	Barcelona		Spain	08036
19	Guys & St; Thomas NHS Trust	London		United Kingdom

Sponsors and Collaborators

• Medtronic Spinal and Biologics

Investigators

• Principal Investigator: Jörg Franke, PD Dr., Klinik für Wirbelsäulenchirurgie; Dortmund

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Medtronic Spinal and Biologics
• ClinicalTrials.gov Identifier: NCT01143324
• Other Study ID Numbers: MASTERS-D Study
• First Posted: Jun 14, 2010
• Last Update Posted: Jan 8, 2019
• Last Verified: Jan 1, 2016

• Keywords provided by Medtronic Spinal and Biologics: Single or double level instrumented fusion; Degenerative lumbar spine; PLIF; TLIF; MAST procedure

Study Results

Participant Flow

Pre-assignment Detail	In total 255 patients were enrolled. Three patients were not submitted to a minimally invasive MAST fusion procedure and therefore excluded from further analysis. Number of participants started in the participant flow is 252.

Arm/Group Title	MAST™ Procedure
Arm/Group Description	Single Arm Study with MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Period Title: Overall Study
STARTED	252
COMPLETED	233
NOT COMPLETED	19

Baseline Characteristics

Arm/Group Title	MAST™ Procedure
Arm/Group Description	Single Arm Study with MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Overall Participants	252
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	53.8 (11.8)
Sex: Female, Male (Count of Participants)
Female	142 56.3%
Male	110 43.7%
Region of Enrollment (Number) [Number]
Portugal	10 4%
Slovakia	7 2.8%
Greece	1 0.4%
Spain	4 1.6%
Austria	25 9.9%
Israel	8 3.2%
Italy	16 6.3%
United Kingdom	11 4.4%
Czechia	40 15.9%
Canada	14 5.6%
Belgium	15 6%
Poland	4 1.6%
Germany	81 32.1%
Netherlands	16 6.3%

Outcome Measures

1. Primary Outcome

Title	Time From Surgery to First Ambulation.
Description	The primary objective of the study is to access the short term recovery (from surgery to hospital discharge) since the minimally invasive lumbar fusion techniques are expected to be associated with immediate short-term benefits. Patients undergoing minimally invasive procedures are reported to recover earlier from surgery particularly with a shorter time to first ambulation and shorter discharge as compared to the standard open procedures. Outcome measure timeframe for time from surgery to first ambulation is assessed up to hospital discharge as pts are all ambulated before discharge from the hospital.
Time Frame	From date of Surgery to date of First ambulation, assessed up to hospital discharge.

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Mean (Standard Deviation) [Days from surgery to first ambulation]	1.3 (0.5)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value
	Comments
	Method
	Comments
Method of Estimation	Estimation Parameter	Mean
	Estimated Value	1.3
	Confidence Interval	(2-Sided) 95%; 1.2 to 1.3
	Parameter Dispersion	Type: Standard Deviation; Value: 0.5
	Estimation Comments

2. Secondary Outcome

Title	Back Pain Intensity Visual Analog Scale (VAS) Score as Compared to Baseline.
Description	Relief of Back Pain intensity at 12 months compared to the baseline using the Back Pain Intensity Score assessed on a 10 cm Visual Analog Scale (VAS). The endpoint is the difference between baseline and 12 months of the patient's back-pain intensity score on a Visual Analogue Scale (VAS). A standardized visual analogue scale (0cm-10cm; with 0cm meaning 'no pain' and 10cm meaning 'worst possible pain') was used. Large values of the VAS score represent large degree of pain. Large (negative) change in VAS score (12 months - baseline) represents large relief of pain.
Time Frame	Baseline, 12 months

Outcome Measure Data

Analysis Population Description

The number of analyzed at 12 months only included subjects who had available data.

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Pre-operative (N=252)	6.2 (2.3)
12 Months (N=226)	2.9 (2.5)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value	<0.0001
	Comments
	Method	t-test, 2 sided
	Comments
Method of Estimation	Estimation Parameter	Difference from pre-op mean
	Estimated Value	-3.3
	Confidence Interval	(2-Sided) 95%; -3.6 to -2.9
	Parameter Dispersion	Type: Value:
	Estimation Comments

3. Secondary Outcome

Title	Leg Pain Intensity VAS Score as Compared to Baseline
Description	Leg pain intensity (using VAS intensity score) as compared to baseline. Relief of Leg Pain intensity at 12 months compared to the baseline using the Back Pain Intensity Score assessed on a 10 cm Visual Analog Scale (VAS). The endpoint is the difference between baseline and 12 months of the patient's leg-pain intensity score on a Visual Analogue Scale (VAS). A standardized visual analogue scale (0cm-10cm; with 0cm meaning 'no pain' and 10cm meaning 'worst possible pain') was used. Large values of the VAS score represent large degree of pain. Large (negative) change in VAS score (12 months - baseline) represents large relief of pain.
Time Frame	Baseline, 12 months

Outcome Measure Data

Analysis Population Description

The number of analyzed at 12 months only included subjects who had available data.

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Baseline (N=252)	5.9 (2.8)
12 months (N=226)	2.2 (2.6)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value	<0.0001
	Comments
	Method	t-test, 2 sided
	Comments
Method of Estimation	Estimation Parameter	Difference from pre-op mean
	Estimated Value	-3.8
	Confidence Interval	(2-Sided) 95%; -4.2 to -3.3
	Parameter Dispersion	Type: Value:
	Estimation Comments

4. Secondary Outcome

Title	EQ-5D Questionnaire (When it is a Routine Practice) as Compared to Baseline.
Description	EQ-5D questionnaire as compared to baseline measurement. EQ-5D Index was calculated based on answers provided in the questionnaire. Applicable to a wide range of health conditions and treatments, the EQ-5D provides a simple descriptive profile and a single index value for health status. The EQ-5D-3L consists of the EQ-5D-3L descriptive system and the EQ visual analogue scale (EQ VAS). The EQ-5D descriptive system comprises 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 3 levels: no problems, some problems, extreme problems. The respondent is asked to indicate his/her health state by ticking in the box against the most appropriate statement in each of the 5 dimensions. EQ VAS records the respondent's self-rated health on a vertical 20 cm VAS where the endpoints are labelled 'Best imaginable health state' at the top and 'Worst imaginable health state' at the bottom, having numeric values of 100 and 0 respectively.
Time Frame	Baseline, 12 months

Outcome Measure Data

Analysis Population Description

The number of analyzed at 12 months only included subjects who had available data.

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	204
Baseline (N=204)	0.34 (0.32)
12 Months (N=182)	0.71 (0.28)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value	<0.0001
	Comments
	Method	t-test, 2 sided
	Comments
Method of Estimation	Estimation Parameter	Difference from pre-op mean
	Estimated Value	0.35
	Confidence Interval	(2-Sided) 95%; 0.30 to 0.41
	Parameter Dispersion	Type: Value:
	Estimation Comments

5. Secondary Outcome

Title	Fusion Rate as Assessed by CT Scan or X-Rays, in Those Sites Where This Assessment is Standard of Care.
Description	Fusion rate as assessed by the CT Scan or X-Rays, in those sites where this assessment is standard of care.
Time Frame	12 months

Outcome Measure Data

Analysis Population Description

One hundred and thirty one-level patients (=130 LEVELS) and 24 two-level patients (=48 LEVELS) were assessed for fusion at 12 months per CIP defined criteria.

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	154
Measure Number of levels assessed	178
One level fusion (levels n=130)	118
Two level fusion (levels n=48)	43

6. Secondary Outcome

Title	Number of Patients Who Utilized Rehabilitation Programs
Description	The number of patients who utilized rehabilitation programs was documented (when required).
Time Frame	From 6-12 months after the day of surgery

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Number [participants]	61 24.2%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value
	Comments
	Method
	Comments
Method of Estimation	Estimation Parameter	Percentage
	Estimated Value	27.0
	Confidence Interval	() %; to
	Parameter Dispersion	Type: Value:
	Estimation Comments	61/226 patients underwent a rehabilitation programs between 6 and 12 months follow up visit, making it 27.0 % of the total.

7. Secondary Outcome

Title	Proportion of Patients Needing a Second Intervention at the Treated Level(s) (Reoperation Rates).
Description	Proportion of the patients needing a second intervention at the treated level(s) (reoperation rates).
Time Frame	From baseline until 12 months

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Number [Participants]	3 1.2%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value
	Comments
	Method
	Comments
Method of Estimation	Estimation Parameter	Percentage
	Estimated Value	1.2
	Confidence Interval	() %; to
	Parameter Dispersion	Type: Value:
	Estimation Comments	The rate of additional lumbar spinal surgeries at treated level was 1.2% (3/252) patients.

8. Secondary Outcome

Title	Proportion of Patients Needing Intervention at Adjacent Level(s).
Description	Proportion of the patients needing intervention at adjacent level(s).
Time Frame	From Baseline until 12 months

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Number [Participants]	4 1.6%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value
	Comments
	Method
	Comments
Method of Estimation	Estimation Parameter	Percentage
	Estimated Value	1.6
	Confidence Interval	() %; to
	Parameter Dispersion	Type: Value:
	Estimation Comments	The rate of additional lumbar spinal surgeries at the same level was 1.6% (4/252) patients.

9. Secondary Outcome

Title	Document Change in Pain Medication Consumption Over Time as Compared With Baseline. Baseline.
Description	Document the change in pain medication consumption one year after surgery , as compared with baseline. The endpoint is the number of participants taking pain medication at baseline and number of participants taking pain medication in the week before the 12 months follow up visit.
Time Frame	Baseline, 12 months

Outcome Measure Data

Analysis Population Description

The number of analyzed at 12 months only included subjects who had available data.

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Participants taking medication at baseline N=252	185 73.4%
Participants taking medication at 12 months N=233	107 42.5%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value
	Comments
	Method
	Comments
Method of Estimation	Estimation Parameter	Percentage at 12 months
	Estimated Value	47.6
	Confidence Interval	() %; to
	Parameter Dispersion	Type: Value:
	Estimation Comments

10. Secondary Outcome

Title	Document Adverse Events Occurrence Throughout the Study.
Description	Document the Adverse Events occurrence throughout the study. All adverse events have been included regardless visit windowing.
Time Frame	From Baseline until 12 months

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Number [Number of reported adverse events]	125

11. Secondary Outcome

Title	ODI Difference 12 Months After the Surgery as Compared to Baseline.
Description	Oswestry Disability Index (ODI) 12 months after the surgery as compared to baseline. The Oswestry Disability Index (ODI) derives from the Oswestry Low Back Pain Questionnaire, it is used to measure disability for low back pain. The index is scored from 0 to 100; 0 meaning 'no disability' and 100 meaning 'maximum disability'.
Time Frame	Baseline, 12 months

Outcome Measure Data

Analysis Population Description

The number of analyzed at 12 months only included subjects who had available data.

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	251
Baseline (N=251)	45.5 (15.4)
12 Month (N=226)	22.4 (18.8)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value	<0.0001
	Comments
	Method	t-test, 2 sided
	Comments
Method of Estimation	Estimation Parameter	Difference from pre-op mean
	Estimated Value	-23.0
	Confidence Interval	(2-Sided) 95%; -25.5 to -20.5
	Parameter Dispersion	Type: Value:
	Estimation Comments

12. Secondary Outcome

Title	Number of Patients That Returned to Work 12months After the Surgery.
Description	Document number of participants that returned to work 12 months after surgery.
Time Frame	12 months after the surgery

Outcome Measure Data

Analysis Population Description

The analyzed subjects at 12 months only included the subjects who had available data.

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Number of participants working at baseline(N=252)	79 31.3%
Number of participants working at 12 months (N=227	97 38.5%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value
	Comments
	Method
	Comments
Method of Estimation	Estimation Parameter	Percentage
	Estimated Value	42.7
	Confidence Interval	() %; to
	Parameter Dispersion	Type: Value:
	Estimation Comments

13. Primary Outcome

Title	Time to Surgery Recovery Day.
Description	The primary objective of the study is to access the short term recovery (from surgery to discharge) since the minimally invasive lumbar fusion techniques are expected to be associated with immediate short-term benefits. Patients undergoing minimally invasive procedures are reported to recover earlier from surgery particularly with a shorter time to first ambulation and shorter discharge as compared to the standard open procedures. Surgery recovery day is defined as the day when patients fulfils following criteria : patient no longer needs intravenous infusion of analgesic drugs, there are no surgery related complications (AEs) impending discharge of patient, patient no longer needs nursing care. The objective of the surgery recovery day assessment is to collect the day when the patient could be discharged based on his actual clinical condition because the effective day of discharge may be prolonged by factors other than the patient's clinical recovery such as social factors.
Time Frame	From date of surgery until date of surgery recovery day assessed up to hospital discharge.

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
Measure Participants	252
Mean (Standard Deviation) [Days]	3.2 (2.0)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	MAST™ Procedure
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value
	Comments
	Method
	Comments
Method of Estimation	Estimation Parameter	Mean
	Estimated Value	3.2
	Confidence Interval	() 95%; 2.9 to 3.4
	Parameter Dispersion	Type: Standard Deviation; Value: 2.0
	Estimation Comments

Adverse Events

Time Frame	1 year.
Arm/Group Title	MAST™ Procedure
Arm/Group Description	MAST™ procedure: Single or double level instrumented fusion receiving the CD Horizon® Spinal System using PLIF or TLIF techniques via a MAST™ procedure.
All Cause Mortality
	MAST™ Procedure
	Affected / at Risk (%)	# Events
Total	/ (NaN)
Serious Adverse Events
	MAST™ Procedure
	Affected / at Risk (%)	# Events
Total	20/252 (7.9%)
Cardiac disorders
Myocardial infarction	1/252 (0.4%)	1
Immune system disorders
Hypersensitivity	1/252 (0.4%)	1
Infections and infestations
Urosepsis	1/252 (0.4%)	1
Injury, poisoning and procedural complications
Meniscus lesion	1/252 (0.4%)	1
Confusion postoperative	1/252 (0.4%)	1
Musculoskeletal and connective tissue disorders
Pain in extremity	4/252 (1.6%)	4
Intervertebral disc protrusion	1/252 (0.4%)	1
Back pain	4/252 (1.6%)	4
Intervertebral disc degeneration	1/252 (0.4%)	1
Nervous system disorders
Cervicobrachial syndrome	1/252 (0.4%)	1
Polyneuropathy	1/252 (0.4%)	1
Spinal haematoma	1/252 (0.4%)	1
Renal and urinary disorders
Renal failure chronic	1/252 (0.4%)	1
Surgical and medical procedures
Bladder neck suspension	1/252 (0.4%)	1
Cholecystectomy	1/252 (0.4%)	1
Vascular disorders
Hypotension	1/252 (0.4%)	1
Circulatory collapse	1/252 (0.4%)	1
Other (Not Including Serious) Adverse Events
	MAST™ Procedure
	Affected / at Risk (%)	# Events
Total	66/252 (26.2%)
Ear and labyrinth disorders
Vertigo	1/252 (0.4%)	1
Eye disorders
Cataract	1/252 (0.4%)	1
Gastrointestinal disorders
Nausea	4/252 (1.6%)	4
Vomiting	2/252 (0.8%)	2
General disorders
Pyrexia	1/252 (0.4%)	1
Implant site effusion	2/252 (0.8%)	2
Infections and infestations
Incision site abscess	1/252 (0.4%)	1
Urinary tract infection	3/252 (1.2%)	3
Wound infection	1/252 (0.4%)	1
Injury, poisoning and procedural complications
Dural tear	4/252 (1.6%)	4
Fractured coccyx	1/252 (0.4%)	1
Postoperative fever	1/252 (0.4%)	1
Procedural nausea	1/252 (0.4%)	1
Musculoskeletal and connective tissue disorders
Back pain	25/252 (9.9%)	31
Intervertebral disc degeneration	1/252 (0.4%)	1
Arthritis	1/252 (0.4%)	1
Pain in extremity	22/252 (8.7%)	30
Arthralgia	4/252 (1.6%)	4
Musculoskeletal pain	1/252 (0.4%)	1
Sacroiliitis	1/252 (0.4%)	1
Nervous system disorders
Headache	1/252 (0.4%)	1
Hypoesthesia	3/252 (1.2%)	3
Lumbar radiculopathy	3/252 (1.2%)	3
Respiratory, thoracic and mediastinal disorders
Sleep apnoea syndrome	1/252 (0.4%)	1
Surgical and medical procedures
Knee arthroplasty	1/252 (0.4%)	1
Vascular disorders
Hypertension	1/252 (0.4%)	1

Limitations/Caveats

Limitations of this study include the lack of a direct comparison of outcomes of minimally invasive surgery and open surgery, since it was designed as an observational trial and not designed as a randomized controlled trial.

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Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

Confidential Disclosure Agreements were signed by all investigators. The information had to be kept confidential and investigators agreed not to disclose information to any third party.