An observational study in Older Adults (60 - 85 Years Old), Sarcopenia and Lumbar Fusion Surgery, sponsored by Karamanoğlu Mehmetbey University. Completed at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-10-14.
Sponsored by Karamanoğlu Mehmetbey University · Observational
Abstract Background: Lumbar fusion (LF) surgery successfully restores the mechanical stability of the spine; however, postoperative kinesiophobia and complications can trigger secondary sarcopenia. Conventional diagnostic algorithms focus on muscle mass and active strength, leading to the neglect of passive viscoelastic alterations in muscle tissue. This study aimed to investigate the prevalence of secondary sarcopenia and changes in in vivo muscle biomechanics in patients undergoing LF surgery, using ultrasonography and digital myotonometry methods.
Methods: This single-center, prospective, comparative, cross-sectional study included 56 older patients with lumbar spinal stenosis. It comprised 31 patients with a history of lumbar fusion (LF) surgery and a control group of 25 patients undergoing conservative treatment, matched for age and body mass index. Sarcopenia staging was performed using ISarcoPRM and EWGSOP2 diagnostic criteria. Appendicular muscle mass was measured via the ultrasound-based "Sonographic Thigh Adjustment Ratio" (STAR). The passive viscoelastic properties of the rectus femoris (RF), tibialis anterior, medial gastrocnemius, and lumbar extensor muscles were assessed using a handheld digital myotonometer.
This study is designed as a single-center, prospective, comparative cross-sectional investigation to evaluate the prevalence of secondary sarcopenia and alterations in passive muscle biomechanics among patients with a history of multilevel lumbar decompression and fusion (LF) surgery for lumbar spinal stenosis (LSS). To delineate long-term musculoskeletal adaptations associated with surgical intervention, findings are compared against an age- and body mass index (BMI)-matched control cohort of LSS patients managed exclusively with conservative therapy.
Following screening and enrollment at the outpatient Physical Medicine and Rehabilitation clinics, eligible participants undergo standardized evaluations in a temperature-controlled environment (22-24°C) after a 15-minute resting acclimatization period to ensure complete neuromuscular relaxation. Assessments follow a multi-step sequence:
Sarcopenia Screening and Functional Stratification: Initial risk screening is conducted using the validated SARC-F questionnaire. Isometric handgrip strength is assessed using a calibrated hydraulic hand dynamometer in accordance with American Society of Hand Therapists (ASHT) positioning. Dynamic lower-extremity physical performance is evaluated using the five-repetition chair stand test and the 4-meter usual gait speed test. Diagnostic categorization (probable, confirmed, and severe sarcopenia) is established based on the ISarcoPRM algorithm, supplemented by EWGSOP2 reference frameworks.
Ultrasonographic Muscle Architecture Assessment: High-resolution B-mode ultrasonography (Clarius L7 HD3 linear transducer) is utilized to evaluate muscle quantity and structural atrophy. Anterior thigh muscle thickness (rectus femoris and vastus intermedius) is measured at the midpoint between the anterior superior iliac spine (ASIS) and the superior patellar border to calculate the Sonographic Thigh Adjustment Ratio (STAR), normalizing muscle thickness to BMI. Lumbar multifidus muscle thickness is similarly quantified bilaterally at the L4-L5 intervertebral space in the prone position. All acoustic measurements employ abundant transmission gel to prevent soft-tissue compression artifacts.
In Vivo Passive Myotonometric Biomechanics: Non-invasive mechanical oscillation assessments are performed using a digital myotonometer (MyotonPRO) to record muscle tone (oscillation frequency, Hz), biomechanical stiffness (dynamic stiffness, N/m), and elasticity (logarithmic decrement). Standardized anatomical sites are tested bilaterally in a relaxed state:
Rectus Femoris: Midpoint between the ASIS and the superior patellar border (supine).
Tibialis Anterior: 12 cm distal to the lateral femoral condyle (supine).
Medial Gastrocnemius: 30 cm proximal to the posterior medial malleolus (prone).
Lumbar Extensors: 2 cm lateral to the L3-L4 intervertebral space (prone). Measurements are acquired in multi-scan mode applying consecutive mechanical impulses, and bilateral average parameters are computed for comparative biomechanical analysis.
1,240 studies on the registry are indexed under Sarcopenia; 405 are open to participants now.
This study's enrollment of 51 is below the median of 120 across 433 observational studies indexed under Sarcopenia.
Browse Sarcopenia studies →Karamanoğlu Mehmetbey University is the lead sponsor of 69 studies on the registry; 19 are open to participants now.
Counted across the registry records on this site, refreshed daily.
This single-center, prospective, comparative, cross-sectional study included 56 older patients with lumbar spinal stenosis. It comprised 31 patients with a history of lumbar fusion (LF) surgery and a control group of 25 patients undergoing conservative treatment, matched for age and body mass index.
Inclusion criteria for the LF group:
Inclusion criteria for the control group:
Exclusion Criteria:
Patients who underwent multilevel lumbar fusion surgery at least 3 months ago
The group with chronic low back pain due to lumbar spinal stenosis
Assessment of sarcopenia using the SARC-F test
The SARC-F is a validated self-report screening tool comprising five components: strength (lifting and carrying 10 pounds), assistance in walking across a room, rising from a chair, climbing a flight of 10 stairs, and frequency of falls in the past year. Each item is scored from 0 to 2 points, yielding a total score ranging from 0 to 10. A cutoff score of ≥4 was considered indicative of sarcopenia risk and predictive of impaired muscle function, prompting subsequent quantitative muscle strength and ultrasound assessments.
Time frame: 02.02.2026-01.09.2026
Hand dynamometer for muscle strength performance
A Baseline® hydraulic hand dynamometer (90 kg capacity) was used to assess muscle strength in accordance with ISarcoPRM diagnostic criteria. According to the test procedure, three measurements of handgrip strength must be taken-with one-minute intervals between each-and the average value recorded. The measurement results are expressed in kilograms. ISarcoPRM recommends cut-off values of 32 kg for men and 19 kg for women regarding grip strength.
Time frame: 02.02.2026-01.09.2026
The chair stand test
The chair stand test is a fundamental tool used to evaluate lower-extremity function and muscle strength in older adults and various patient populations. In this test, participants begin by sitting on a chair without armrests, with their arms crossed over their chests and their hip and knee joints flexed at 90°. Assessment commences after participants receive the "ready" and "start" commands. The researcher records the time required to complete five sit-to-stand cycles. The chair stand test is performed twice with a 1-2 minute rest interval, and the fastest time is used for evaluation. ISarcoPRM recommends a cutoff value of ≥12 seconds for the chair stand test .
Time frame: 02.02.2026-01.09.2026
Calculating the Sonographic Thigh Adjustment Ratio (STAR).
Ultrasonographic evaluations will be performed using a high-resolution portable ultrasound system (Clarius L7 HD3, Clarius Mobile Health, Vancouver, Canada) equipped with a 4-13 MHz linear transducer. Measurements were performed with participants in a supine position, with knees in full extension and quadriceps muscles completely relaxed. The probe was placed transversely at the midpoint of the longitudinal line connecting the anterior superior iliac spine (ASIS) and the superior border of the patella. A generous amount of acoustic coupling gel was used to ensure optimal acoustic contact without applying excessive mechanical pressure to the underlying tissues. Anterior thigh muscle thickness was measured (in millimeters) as the vertical distance from the superficial fascia of the \*rectus femoris\* to the femoral periosteum, encompassing both the \*rectus femoris\* and \*vastus intermedius\* muscles. The STAR value was calculated by dividing the anterior thigh muscle thickness (mm) by the b
Time frame: 02.02.2026-01.09.2026
The Thickness of the Multifidus muscle
The thickness of the multifidus muscle-one of the lumbar extensor muscles-was measured at the level of the L4-L5 intervertebral space. Measurements were taken three times at the L4-L5 spinal level while the participants were in the prone position, and the mean value was included in the analysis
Time frame: 02.02.2026-01.09.2026
Muscle Myotonometer
The mechanical properties of gait-related muscles-specifically the rectus femoris (RF), tibialis anterior (TA), and gastrocnemius medialis (GM)-were assessed using a handheld myotonometer (MyotonPRO, Myoton AS, Tallinn, Estonia). Additionally, the biomechanical properties of the lumbar extensor muscles were evaluated using this method. All assessments were performed in a quiet examination room maintained at a constant temperature (22-24°C) following a 15-minute rest period intended to ensure complete physical relaxation and the absence of active voluntary muscle contraction. Measurements were taken bilaterally and evaluated by calculating the mean. This device non-invasively characterizes the biomechanical and viscoelastic properties of muscles
Time frame: 02.02.2026-01.09.2026
Body Mass Index (BMI)
It is obtained by dividing the patient's weight (kg) by the square of their height (meters).
Time frame: 02.02.2026-01.09.2026
Plan to share: Undecided — patient privacy
Ran from Jan 2026 to primary completion in Sep 2026, 7 months.
Of 177 non-industry observational studies under Sarcopenia, half reached primary completion within 25 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 63. This study's 7 months is below that.
Counting every sponsor, half of 180 studies reached it within 25 months; a quarter within 11 and three quarters within 56.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Karamanoğlu Mehmetbey University