1. Return to Sport after ACL Reconstruction
Sara Cordell
Ithaca College
Why did I choose this topic? Difficult for students/new grads to decide this, so many factors involved, are there definitive tests that can help make the decision?, what does the evidence say?, is there a “right way” to decide or is it completely different for each patient?, improvements documented up to 2 years after reconstruction but cannot wait that long

2. Challenge of Deciding Return to Sport
Protocol timeline
Concomitant injuries or complications
Knee stability and strength
Objective vs. subjective data
Reliability, validity, accuracy, functional relevance of tests
Individual circumstances, fears, values, motivation, etc
Demands of particular sport(s)
Clinical experience/judgment
Protocol given by MD- must follow timeline? Depends on MD philosophy
Injuries/comp- meniscal/ligamentous tears/repairs, arthrofibrosis, etc
Knee stab/str- graft stability, knee flexor/extensor strength/ratios usually according to Biodex
Obj/subj- may not match; obj good, subj bad or subj good, obj bad
Tests- are they reliable/valid, do they apply to patient function? Do they mimic the demands of the sport? Can they show true deficits?
Individual/family circumstances
Clinical experience/judgment- most important?

3. Many Factors Involved
No one test/factor that determines return to sport
Many different areas to consider when making return to sport decisions

4. General Return to Sport Guidelines
≥90% symmetry between involved and uninvolved sides for objective testing (isokinetic testing, hop testing, etc)
Full, nonpainful ROM
No joint effusion
Joint stability- KT test ≤3mm side-to-side difference
MD and PT opinions
These are general guidelines for return to sport, but they are somewhat vague. One article discussed an algorithm that had a 4-step progression through the return to sport phase

5. Return to Sport Algorithm According to Myer et al.
Not validated algorithm but backed up by evidence
- No time frame proposed, strictly based on criteria
- IKDC subjective knee form assesses the patient’s perception of their knee injury- symptoms, function, ability to participate in sport
Hard to assess some of these specifically without the proper equipment
thoughts? Opinions? Are these the most important factors for each stage?
Different criteria address subjective measures, strength, balance, equal joint loading, hop testing, agility, overall symmetry

6. Objective Testing Options
Biodex Isokinetic Testing
KT Testing
Agility testing- Modified T-test
Balance testing- Stabilometer
Goniometry to measure symmetry of movement
Compare symmetry of GRFs
Deceleration testing
Hop testing
Great options available but we have limited time and equipment, cannot conduct every test
Deceleration testing- run and full speed and stop suddenly on command, positive for rotary instability if the patient stops w/o using quads or stops in crouched position (>30deg knee flex)

7. Hop Testing
Common tests- single leg hop for distance, 6m timed hop, triple hop for distance, crossover hops for distance
Limb symmetry index (LSI=involved/uninvolved x100% for distance measures, opposite for time)
Begun ~12-16weeks post-op
Pros- test many aspects of LE movement at once, time efficient, minimal equipment
Cons- learning curve, functional relevance, don’t address quality of movement, measurement error
a lot of literature about hop testing so I wanted to research the reliability and validity of the measures and also determine the most clinically useful/relevant tests to use
Basic criteria before hopping- no effusion, painfree hopping, ≥80% strength, full ROM, normal gait pattern
Why use hop testing- neuromusc control, strength, confidence in limb, minimal equipment and time
want tests to “mimic demands of dynamic knee stability”

8. Hops in Reid et al.

9. Characteristics of Hop Tests
Reliability (ICC)
MDC (%)
Single hop
.92
8.09
6m timed hop
.82
12.96
Triple hop
.88
10.02
Crossover hop
.84
12.25
Overall combination
.93
7.05
Article by Reid examined 4 common hop tests and investigated the reliability of the tests
Single hop was most reliable, but all four together proved to be the best especially when you look at the sensitivities
Using the single hop test alone could increase the risk of a false negative
ICC (reliability)- measures degree of consistency, error
Minimal detectable change= MDC
Sensitivity- snout- good at ruling condition out good sensitivity here means that there will be few false negatives
Four tests together- sensitivity= 82%
Single hop test alone- sensitivity= 38-52%

10. Hops in Gustavsson et al.
Vertical jump
Single hop for distance
Drop jump followed by double hop
Square hop
Side hop
5 hops examined by Gustavsson et al.

11. Hop Test Evaluation Statistic Vertical jump Hop for distance
Drop jump w/ double hop
Square hop
Side hop
Sensitivity 86 63 51 69
Specificity 87
100 67
Accuracy 74 56
Assessed 6mo post-op
- Vertical jump performed best in all 3
Spin- better at ruling discrepancy in avoid false positives, won’t over report
Good spin, bad snoutIf positive test for deficiency, can be almost sure that they have the deficiency but if they test negative for deficiency you cannot be absolutely sure that it is a true negative

12. Hop Test Battery Vertical jump, single hop for distance, side hop
Sensitivity: 91% for identifying patient as abnormal when at least 1 of the 3 tests was abnormal
Accuracy: 84% for truly normal subjects and 88% for truly abnormal subjects
Square hop eliminated b/c of poor sensitivity/specificity and accuracy; drop jump eliminated b/c of high correlation with single hop, measured same ability

13. At 6 months post-op… 54% had abnormal LSI in ALL 3 tests
91% had an abnormal value in at least one of the 3 tests
Only 9% had all normal LSI values
Used 3 hop test battery with athletes 6months post-op and found these results…
Abnormal= <90%
Interesting b/c in theory they should be about ready to resume sport

14. Patient Example Reid Test Battery Test *Left Right LSI Single Hop
91.3%
6m Hop
2.5s
2.63s
105.2%
Triple Hop
4.72m
4.82m
97.9%
Crossover Hop
4.1m
4.8m
85.4%
Applied to Sally
According to the first test battery, subject is just about “normal”
According to second, he has some work to do
Does this example indicate second test battery is better than the first?
This example supports the research- the battery proposed by Reid had a sensitivity of 82% vs 91% in the Gustavsson battery. Therefore the first set of tests may have some false negatives
Gustavsson Test Battery
Test
*Left
Right
LSI
Single Hop
1.48m
1.62m
91.3%
Vertical Jump
10.43in
13.03in
80.0%
Side Hop
34in
49in
69.3%

15. Effect of Testing in Fatigued State
Augustsson et al. evaluated effect of fatigue on single hop testing results
Fatigue- repeat as many reps as possible at 50% 1RM
All patients included in study had ≥90% symmetry in non-fatigued conditions
After pre-exhaustion exercise, 68% demonstrated abnormal hop symmetry
Augustsson et al.- rationale was that injuries occur in fatigued state
All subjects included in the study had to demonstrate normal LSIs so it was shocking when only 32% were still designated as normal after fatigue testing
Should athletes be tested in non-fatigued and fatigued environments?

16. Take Home Messages Do not use only one or two testing methods
Consider whole athlete and demands of sport
Reference protocol timeline but also use functional goals as criteria for progression
No objective tests are perfect, supplement with clinical judgment and experience
Consider testing athlete in non-fatigued and fatigued conditions

17. What is your opinion? Criteria based algorithm as proposed by Myer?
Can you identify the most important factors when deciding return to sport?
Most clinically useful objective measures?
Most reliable/valid hop tests?
Testing in fatigued vs. non-fatigued state?
Commonly overlooked factors?

18. References
Augustsson J, Thomeé R, Karlsson J. Ability of a new hop test to determine functional deficits after anterior cruciate ligament reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal Of The ESSKA. Sept 2004;12(5):
Gustavsson A, Neeter C, Karlsson J, et al. A test battery for evaluating hop performance in patients with an ACL injury and patients who have undergone ACL reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal Of The ESSKA. August 2006;14(8):
Hartigan EH, Axe MJ, Snyder-Mackler L. Time line for noncopers to pass return-to-sports criteria after anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther. 2010; 40:
Kvist J. Rehabilitation following anterior cruciate ligament injury: current recommendations for sports participation. Sports Medicine ;34(4):
Myer G, Paterno M, Ford K, Quatman C, Hewett T. Rehabilitation after anterior cruciate ligament reconstruction: criteria-based progression through the return-to-sport phase. The Journal Of Orthopaedic And Sports Physical Therapy. June 2006;36(6):
Reid A, Birmingham T, Stratford P, Alcock G, Giffin J. Hop testing provides a reliable and valid outcome measure during rehabilitation after anterior cruciate ligament reconstruction. Physical Therapy . March 2007;87(3):