Factors Associated with Excellent Early Functional and Isokinetic Test Results Following ACL Reconstruction

Aaron J. Krych, MD Jessica A. Woodcock, MD

Joseph A. Morgan, MD Bruce A. Levy, MD

Michael J. Stuart, MD Diane L. Dahm, MD

Department of Orthopedic Surgery and Sports Medicine Mayo Clinic

Rochester, MN

Background •  The incidence of ACL tear has been reported at 81

ruptures per 100,000 people 2

•  Only 2/3 of athletes return to preinjury level of activities following ACL reconstruction 1

•  Average return to moderate sports was at 5.8 months 3

•  Average return to strenuous sports was at 8.1 months 3

• To identify factors associated with excellent functional and isokinetic testing results at six months following ACL reconstruction surgery.

Purpose

•  352 primary ACL reconstructions by single surgeon 1998-2005

•  All patients were given option of Allograft vs. Autograft

•  Retrospective review •  -Factors: •  -Age -Graft type •  -Gender -Quad activation •  -BMI -IKDC/Tegner scores •  -Intraarticular concomitant injuries

•  -Functional and Isokinetic Testing at 6 months.

Methods

•  Criteria for testing at 6 months •  Absence of Effusion •  No patellofemoral pain or pain with weightbearing •  Objective stability on exam

•  Functional Testing •  Single hop •  Vertical jump •  Triple jump •  Satisfactory result = >90% of opposite limb

•  Isokinetic Testing •  Maximal torque of hamstrings and quads were measured at

60o/s and 180o/s and recorded •  Satisfactory result = >85% of opposite limb

Methods Functional and Isokinetic Testing

Results • Study Group

•  224 Primary ACL reconstructions •  Mean age 26 (12-59) •  Mean BMI 25.8 (17-44) •  162 Autografts

•  134 BTB •  28 Hamstrings

•  62 Allografts

•  Excellent Performance Group • Patients who performed

satisfactorily in at least 6 of 7 of categories (3 functional tests and 4 strength tests).

Performance Groups

0 20 40 60 80

100 120 140 160 180

Excellent Not Cleared

52

172

Patie

nts (

#)

Results

22.5

23

23.5

24

24.5

25

25.5

26

26.5

27

27.5

Excellent Not Cleared

Age Age

Excellent Performance

Group

Not Cleared

P-Value

Age* 24.1 ± 12.1 27.1 ± 11.7

0.01 *

Gender 25 (48.1%) m 27 (51.9%) f

68 (39.5%) m 104 (60.5%) f

0.27

BMI*

24.5 ± 3.8

26.2 ± 4.8 0.03 *

Articular Damage *

15 (28.8%) 76 (44.2%) 0.048 *

Age

P = 0.01*

Results

23.5

24

24.5

25

25.5

26

26.5

Excellent Not cleared

BM

I

BMI

24.5*

26.2*

P = 0.03*

Articular Damage

01020304050607080

Pat

ient

s

Excellent Not cleared

CartilageDegeneration

BMI

P = 0.048*

Results Allograft vs. Autograft Excellent Outcome Group Not Cleared P-Value

PT autograft HS autograft PT allograft

28 (53.8%) 10 (19.2%) 15 (28.8%)

107 (62.2%) 17 (9.9%) 47 (27.3%)

0.29

Allograft vs Autograft

37 (71.2%) 15 (28.8%)

124 (72.1%) 48 (27.9%)

0.90

0

10

20

30

40

50

<18 18-30 >30

Exe

llent

Out

com

e %

Age

Allograft Autograft

P=0.66 P=0.75 P=0.047*

0

0.1

0.2

0.3

0.4

10 20 30 40 50 60 Age

Estimated probability of excellent outcome

Patients > 30 years old Allograft vs. Autograft

0

5

10

15

20

25

30

35

40

Allograft Autograft

Excellent Not Cleared

P=.047*

1

13

Results

•  Younger age, lower BMI, and minimal cartilage degeneration is significantly associated with excellent functional and isokinetic test results at 6 months post operatively.

•  Patients over 30, who underwent Allograft reconstruction were more likely to exhibit excellent test results at 6 months.

•  The safety of returning patients with an Allograft reconstruction to sport at 6 months has not been established.

Conclusion

1.  Biau DJ, Tournoux C, Katsahian S, Schranz P, Nizard R. ACL reconstruction: a meta-analysis of functional scores. Clin Orthop Relat Res. 2007 May;458:180-7.

2.  Frobell RB, Lohmander LS, Roos HP. Acute rotational trauma to the knee: poor agreement between clinical assessment and magnetic resonance imaging findings. Scand J Med Sci Sports. 2007 Apr;17(2):109-14.

3.  Harner CD, Fu FH, Irrgang JJ, Vogrin TM. Anterior and posterior cruciate ligament reconstruction in the new millennium: a global perspective. Knee Surg Sports Traumatol Arthrosc 2001;9(6):330-6.

4.  Lyman S, Koulouvaris P, Sherman S, Do H, Mandl LA, Marx RG. Epidemiology of anterior cruciate ligament reconstruction: trends, readmissions, and subsequent knee surgery. J Bone Joint Surg Am. 2009 Oct;91(10):2321-8

References