Question 1

What did the study find?

Accepted Answer

Gracilis volume change between 6-12 months was -1.6 cm3 (SD 4.6) in the STG group vs +2.8 cm3 (SD 6.8) in the ST group (p=0.026); adductor longus showed -2.4 cm3 (SD 12.0) vs +11.1 cm3 (SD 21.2) (p=0.020), with adductor longus hypertrophy in 30% vs 72% of cases (p=0.022). Gracilis hypertrophy rates (35% vs 67%) were not statistically different (p=0.103).

Question 2

What was the study design?

Accepted Answer

Level II evidence: a pre-planned MRI subgroup analysis nested within a prospective, double-blinded RCT (DOSTAR), with only 38 of the presumably larger trial cohort (20 STG, 18 ST) undergoing serial MRI at both 6 and 12 months.

Question 3

How trustworthy is the methodology?

Accepted Answer

Randomisation and blinding come from the parent RCT, which is a methodological strength, but this is a small, non-prespecified-looking secondary analysis restricted to patients who happened to receive both MRI scans, so selection/attrition bias is a real concern, there's no reporting of how the 38 relate to total trial enrolment or why others were excluded. The adductor longus finding rests partly on a post-hoc linear regression linking it to gracilis change, which shows association, not an independently randomised comparison for that muscle. Wide standard deviations relative to the mean differences (e.g. ±21.2 cm3 around an 11.1 cm3 mean) suggest substantial individual variability and fragile p-values, and absolute baseline muscle volumes aren't given so percentage change versus total muscle mass can't be judged from the abstract.

Question 4

What is the overall appraisal?

Accepted Answer

The gracilis finding is biologically coherent and plausibly causal, since only the STG group had the tendon harvested, and it echoes rather than contradicts the existing donor-site morbidity literature. But the magnitude (a few cm3 swing on an unreported baseline volume) is hard to judge as clinically meaningful without a linked strength or function measure, and the inconsistency between a significant volume difference and a non-significant hypertrophy-rate difference for gracilis (p=0.103) suggests the volume result is statistically fragile rather than a clean signal. Several thigh muscles were compared between groups with no stated correction for multiple testing, so the two 'significant' findings (gracilis, adductor longus) should be read against that background risk of a false positive. The adductor longus signal is intriguing but correlational and hypothesis-generating rather than a directly randomised comparison, so causal language in the conclusion ('may adversely affect') outruns what a single correlation analysis in 38 patients can support. This is also an MRI substudy of a larger DOSTAR cohort, only 38 of whom were scanned; how that subset was selected, and whether it dif

Question 5

What is the main limitation?

Accepted Answer

No functional or strength data (hip adduction strength, hop testing, return-to-sport metrics) are reported alongside the volume changes, so it's unclear whether this structural deficit translates into anything a patient or clinician would notice. Baseline/absolute muscle volumes aren't given either, so a few cm3 of interval change can't be put in proportion, and multiple thigh muscles were compared without correction for multiple testing.

Question 6

What should clinicians do on Monday?

Accepted Answer

Not a practice-changer on its own, but it adds another data point favouring single-tendon ST graft constructs when graft choice is otherwise equipoised; clinicians managing STG-graft patients should be alert to adductor-group strength and shouldn't assume full thigh muscle recovery by 12 months just because the graft itself is doing well.

Question 7

How do I apply this in practice?

Accepted Answer

For patients reconstructed with an STG (gracilis-harvested) graft, don't assume the adductor group is recovering normally just because knee-specific milestones look fine by 12 months; baseline-test hip adduction strength (Cable Hip Adduction) in mid-rehab and re-test before return-to-sport clearance rather than relying on time-based criteria alone. In clinic, build adductor-specific loading (Copenhagen-style and cable/band adduction progressions) into the mid-to-late rehab phase for STG patients, and treat a persistent adduction deficit or side-to-side asymmetry as a flag to address, not something that resolves with graft healing. On the performance floor, S&C coaches programming change-of-direction and deceleration work for ACL-reconstructed athletes should weight adductor strength into readiness decisions specifically for STG-graft athletes, since adductor weakness is an established risk factor for groin problems in multidirectional sport; this extra scrutiny isn't indicated by this data for ST (single-tendon) graft patients. Treat the adduction-testing suggestion as a sensible precaution drawn from biological plausibility, not a validated protocol, since the paper itself reports

Gracilis tendon harvest for ACL reconstruction impairs gracilis muscle volume recovery and may adversely affect adjacent thigh musculature. MRI-based outcomes from a subgroup of patients enroled in the DOSTAR randomized controlled trial

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