Clinical Decision-Making in ACL Injury: Choosing Reconstruction or Rehabilitation
Patient Profile
Age and Gender: 22-year-old male
Occupation: Air Force department
Chief Complaint: Left knee pain and locking sensation
History of present illness:
Two months ago, while playing badminton, the patient suddenly twisted his left knee. He felt a clicking sensation immediately, followed by severe pain. He was unable to walk properly at that time. The next day, swelling developed in the knee. The swelling reduced gradually within one week. But the pain did not subsided so he consulted an orthopaedic doctor who advised an MRI scan. MRI showed a Grade 2 Partial ACL tear and Grade 1 Meniscus tear. So, surgery was suggested by the doctor. However, the patient was worried about undergoing surgery and preferred conservative management because he is physically active and works in the Air Force. So, he consulted us to seek the possibility of avoiding surgery.
Physical Activity Status:
The patient is highly physically active owing to his Air Force training. He regularly performs strength training for 4 days a week.
Sleep:
Sleep is good. Not affected by pain. He sleeps averagely for 8 hours.
Stress:
Mild to moderate stress is present due to the doctor’s advice for surgery. He is still worrying whether it will be recovered completely through non-surgical rehabilitation.
Past Medical / Surgical History:
No relevant past medical or surgical history related to the current complaints.
Pain analysis:
Intensity: 5/10
Onset: Sudden
Aggravating Factors: Jogging, fast movements, twisting, running.
Relieving Factors: Rest
Location: Entire left knee
Duration: 2 months
Lifestyle Impact: Affected as he is unable to perform the entire Air Force physical duties
Fear of Movement Analysis: Since the doctor suggested surgery, he is worried about the severity of the condition and is scared to do certain movements. So, the doctor-induced fear is present.
Psychosocial Factor Analysis:
Cognitive: he has a good understanding and awareness
Affective: Mildly affected due to fear of surgery
Social: Good support system
Our Understanding of Patients’ Problems
The patient sustained a twisting injury resulting in a partial ACL tear with mild meniscal involvement confirmed on MRI. Currently, he experiences pain during high-demand activities; therefore, a detailed physical examination is required to determine whether structured rehabilitation is sufficient or if surgical intervention needs to be considered.
Physical Examination
Observational Findings
Mild quadriceps wasting on the left side
Mobility Screening
Forward bending: Normal
Overhead squat: couldn’t perform beyond 90° due to left knee pain
ROM Analysis
| ROM | Left (Affected) | Right (Unaffected ) |
|---|---|---|
| Knee Flexion | Active:90 passive:110 | Active:130 passive:130 |
| Knee Extension | Active: -5 passive: -5 | Active: -5 passive: -5 |
This indicates muscular limitation and pain inhibition rather than structural block.
Stability Screening
| Test | Left Leg (Affected) | Right Leg (Unaffected) |
|---|---|---|
| Assisted Single-Leg Squat | 20 reps | 35 reps |
| Side Plank Leg Raise | 42 sec hold | 1 min 8 sec hold |
| Copenhagen Adductor Hold | Unable to perform | 25 sec hold |
| Single-Leg Hamstring Bridge | 33 reps | 30 reps |
| Single-Leg Calf Raise | 14 reps | 16 reps |
This indicates weakness and loss of muscular stability in the left knee.
Single-leg standing balance
Slight discomfort and loss of stability were noted in the affected leg (left side) when compared with the right side.
Special Test Analysis
- Anterior Drawer Test – Negative
- Posterior Drawer Test – Negative
- McMurray Test – Negative
- Thessaly Test – Negative
(No gross instability detected clinically)
Palpation
No tenderness over the quadriceps muscle, patellar tendon, or joint line.
Investigation
MRI: Grade 2 Partial ACL tear, Grade 1 Meniscus tear (Jan, 2026)
Possible Diagnosis
Partial ACL Tear (Grade 2) with Grade 1 Meniscus Tear – Left Knee
Reasons
- Clear twisting mechanism of injury
- MRI confirmation
- Pain during dynamic activity
- Reduced knee flexion
- Quadriceps muscle wasting
- No major instability signs
Why Surgery is Not Required for him:
| S.no | Components | 0 | 1 | 2 | Score |
|---|---|---|---|---|---|
| 1. | Pain | Sports activities | Functional activities | Rest | 0 |
| 2. | Swelling | Sports activities | Functional activities | Rest | 0 |
| 3. | ROM knee flexion | Both active and passive good | Either active or passive good | Both active and passive affected | 2 |
| 4. | ROM terminal knee extension | Both active and passive good | Either active or passive good | Both active and passive affected | 0 |
| 5. | Muscle mass | Not affected | Slightly affected | Highly affected | 1 |
| 6. | Muscle strength | >80% of limb symmetry | 50 – 80% of limb symmetry | <50% of limb symmetry | 1 |
| 7. | Single leg standing stability & balance | Relative same stability in both legs | 50% stability compared to unaffected leg | >50% instability | 1 |
| 8. | Instability episode | No | 1 | >1 | 0 |
| 9. | Presence of Return to Sports Need (RTS) | No need | Recreational | Elite level | 1 |
| 10. | Opinion about surgery | No | Confused | Yes | 1 |
| 11. | MRI- Findings | No significant changes/ grade 1 tear | Grade 2 tear | Full tear / other ligament involvement with ACL | 1 |
| 12. | Special tests | Negative | weak positive | Strong Positive | 0 |
| Total | 8/24 | ||||
The patient obtained a total score of 8 out of 24, corresponding to 33% (8/24 × 100).
Based on the predefined interpretation criteria of the scoring system:
- >75% – strong recommendation for surgical management
- 50–75% – suggests trial of structured rehabilitation with consideration for delayed surgery if functional instability persists
- <50% – Non-surgical rehabilitation as the primary management approach (no requirement for surgery)
As the patient’s score falls below 50%, the findings strongly favour conservative management. Therefore, a structured, progressive physiotherapy rehabilitation program was recommended. Surgery is not required.
Treatment Planning
Since this is a partial ACL tear in a young, active individual, structured rehabilitation for at least 12 weeks is recommended.
Overall Treatment Strategy
- Protect & improve the healing of the ligament
- Restoring knee ROM
- Rebuild lower limb muscle strength to improve neuromuscular control
- Return to sports to accomplish his work-related needs & demands
MONTH 1 – Tissue Protection & Movement Restoration (Week 0 - 4)
Primary Objective:
Restore normal knee range of motion and re-establish muscular control with a protection of the healing ligament.
Clinical Focus:
- Monitor and control joint swelling after activity.
- Restore full knee extension symmetry
- Gradually improve knee flexion within a safe range.
- Rebuild quadriceps activation and neural drive
- Initiate early hamstring co-activation for dynamic support.
- Normalise walking pattern and weight distribution
- Maintain overall physical conditioning without stressing rotational mechanics
- Educate the patient regarding temporary avoidance of aggressive pivoting and high-speed directional changes
At the end of this period, the knee should demonstrate full extension, near-normal flexion, controlled gait, and improved muscle activation without post-activity swelling.
MONTH 2 - Dynamic Control & Functional Progression (Weeks 8–12)
Primary Objective:
Prepare the knee for higher mechanical demands and achive good level of limb symmetry.
Clinical Focus:
- Improve limb symmetry in strength and load capacity
- Advance single-leg control under increasing mechanical stress.
- Introduce controlled impact absorption mechanics
- Develop deceleration control and directional awareness at low intensity.
- Begin gradual running progression in straight-line patterns
- Enhance the rate of force production in a controlled manner.
- Address psychological readiness and confidence in movement
Reassessing strength:
| Test | Left Leg (Affected) | Right Leg (Unaffected) |
|---|---|---|
| Assisted Single-Leg Squat | 25 reps | 27 reps |
| Side Plank Leg Raise | 1 min 6 sec hold | 1 min 10 sec hold |
| Copenhagen Adductor Hold | 24 sec hold | 27 sec hold |
| Single-Leg Hamstring Bridge | 35 reps | 36 reps |
| Single-Leg Calf Raise | 16 reps | 16 reps |
At this stage, the knee should demonstrate stable performance under moderate dynamic stress with symmetrical strength development.
MONTH 3 – Occupational Conditioning & Return to Preparation (>Week 12)
Primary Objective: Prepare for full Air Force physical training demands.
Clinical Focus:
- Achieve high-level limb symmetry and muscular endurance.
- Improve multi-plane load tolerance
- Advance acceleration and deceleration mechanics.
- Develop fatigue resistance under repeated effort
- Integrate cognitive and motor demands under physical load
- Ensure consistent joint response without swelling after higher-intensity training
- Return to full military conditioning should occur only when the individual demonstrates: Symmetrical strength development, a full range of motion
- Absence of swelling following high-load sessions
- Confident movement during high-speed and directional tasks.
After 3 months:
Primary Objective: Preventing recurrence and self-management.
Clinical Focus:
- Explained clearly regarding load management – advised to listen to the body and progressively overload the exercises each time.
- Strength & conditioning guidance provided – about proper workout planning, and how to implement progression, regression, and RPE scales to achieve better outcomes in strength and fitness.