ACL Natural Healing Failure (Case 53): Permanent Discontinuity on MRI and Surgical Decision

Jun Matsumoto Official Page

ACL Case Report #53: Failure of Natural Healing Despite Evo-Devo Exercise — Surgical Decision for Persistent Discontinuity in a 13-Year-Old Female

Summary:

The patient sustained a left knee ACL rupture during a basketball match. Based on a strict consensus of three independent specialists, the initial MRI was classified as Ihara Type IV (indistinct stumps) and ACLOAS Grade 3. Although she reported no knee collapse (giving way) immediately after the injury, she chose to pursue natural healing through Evo-Devo Exercise. She adhered to a rigorous environment, including a walking limit of 3,000 steps per day and a 0–30° extension restriction. However, after 4 months, the final MRI evaluation showed no signs of natural healing, with all specialists confirming persistent discontinuity (ACLOAS Grade 3). Consequently, the decision was made to proceed with surgical reconstruction.

ACL Online Therapy for natural healing

The case reports of ACL natural healing

Facebook ACL Patients Group

Patient Information

Age / Nationality: 13-year-old female, Japanese
Injured side: Left knee

Mechanism of Injury

Date of injury: 10 June 2023
Context: Sustained an injury during a basketball match while falling and twisting the left knee. Interestingly, she reported a history of the knee “slipping out” about once every six months for the past two years, which had always resolved quickly. Following the acute injury, she did not undergo conventional physical therapy and reported no episodes of knee collapse (giving way).

Initial Evaluation (MRI #1)

Date: 12 June 2023
Diagnosis: Left knee complete ACL rupture
Ihara classification: IV (Grade 4) — Unanimously confirmed by 3 independent specialists (indistinct/morphologically poor stumps)
ACLOAS: Grade 3 (complete discontinuity)

[Ihara classification notes]

I = linear/straight tear; II = curved tear; III = tear with displaced stumps; IV = indistinct/unclear stumps.

Initial Policy & Start of Therapy

Start date: 24 June 2023
Format: Online guidance; initiation of Naturalization Therapy (Evo-Devo Exercise)
Brace management: Knee extension strictly restricted to 0–30°
Activity: Walking strictly restricted to ≤3,000 steps/day
Home program: Evo-Devo Exercise continued for 3 months (with an interruption during summer vacation)

Final MRI Evaluation (~4 months)

Date: 25 October 2023
Assessment: ACLOAS Grade 3 (persistent discontinuity) — Confirmed by consensus of 3 specialists
Clinical Finding: Although morphological healing was not observed on MRI, the patient achieved high functional stability without subjective instability or knee collapse.

[ACLOAS (native ACL) notes]

0 = normal; 1 = thickening/intra-ligament high signal with shape and continuity preserved; 2 = thinning/elongation with continuity preserved; 3 = discontinuity.

Author’s Observations

First, this case demonstrates a clear divergence between morphological healing (MRI) and functional stability. Despite the lack of continuity on imaging, the patient remained clinically stable.
Second, the Evo-Devo Exercise appears to have facilitated significant neuromuscular compensation. For a 13-year-old athlete, retraining these evolutionary movement patterns was key to joint stabilization.
Third, the strict adherence to the walking limit and ROM control prevented secondary injuries during the vulnerable healing phase, ultimately supporting her return to a functional lifestyle.

Results

Initial: Ihara IV / ACLOAS 3 (unanimous consensus)
Final: ACLOAS Grade 3 (no morphological healing) — Functional stability maintained
Clinical status: Satisfactory progress with no episodes of knee collapse; currently considering surgical options for a permanent solution.

Summary

Injury (2023/06/10): Left knee complete ACL rupture during basketball.
Functional Recovery: Achieved joint stability through Evo-Devo Exercise despite persistent MRI discontinuity.
Objective Evidence: Rigorous evaluation by three specialists confirms the divergence between imaging and clinical function in this pediatric case.