The Journal of Arthroplasty Vol. 23 No. 7 2008

Total Knee Arthroplasty After Anterior CruciateLigament Reconstruction

Samuel C. Hoxie, MD, Ryan E. Dobbs, MD,Diane L. Dahm, MD, and Robert T. Trousdale, MD

Abstract: Anterior cruciate ligament (ACL) injuries are common, and many of thesepatients go on to ACL reconstruction. At a later date, some may develop symptomaticosteoarthritis and require total knee arthroplasty (TKA). This raises the question:Does prior ACL reconstruction have a deleterious impact on the outcome of kneearthroplasty? Thirty-six cases of patients who underwent ACL reconstruction andthen TKA at a later date were retrospectively reviewed. A cohort of patients withoutACL injuries who underwent TKA for the diagnosis of primary osteoarthritis wereselected to serve as controls. The results of this study demonstrate that previous ACLreconstruction does not have a negative impact on the outcome of future TKA withrespect to range of motion, outcome scores, infection, or patella baja. Key words:knee arthroplasty, anterior cruciate ligament, outcomes.© 2008 Elsevier Inc. All rights reserved.

The anterior cruciate ligament (ACL) providesrotational stability to a healthy knee. Injuries tothe ACL are common, with over 100000 injuriesoccurring annually in the United States [1-3].Although ACL reconstruction has been successfulin restoring rotational stability to the knee [4], itsability to prevent arthritic degeneration of the kneeis unknown. Loss of graft tension and failure of graftfixation are recognized as possible causes ofincreased knee laxity after initially successful ACLreconstruction [5,6]. This residual instability, alongwith articular cartilage and meniscal damage asso-ciated with ACL injury, may be a contributing causein the later development of osteoarthritis.Some patients who have undergone ACL recon-

struction develop symptomatic osteoarthritis andeventually undergo total knee arthroplasty (TKA).Numerous studies have shown that TKA is an

From the The Mayo Clinic, Orthopedic Department, Rochester, MN.Submitted December 4, 2006; accepted August 29, 2007.No benefits or funds were received in support of this study.Reprint requests: Diane L. Dahm, MD, Mayo Clinic, 200 First

St., S.W., Rochester, MN 55905.© 2008 Elsevier Inc. All rights reserved.0883-5403/08/2307-0010$34.00/0doi:10.1016/j.arth.2007.08.017

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effective procedure to relieve knee pain caused byosteoarthritis [7-9]. To our knowledge, no previousstudy has reported the results of TKA in patientswho had previously undergone a reconstructiveprocedure for ACL disruption. The purpose of thisstudy was to investigate what impact, if any, priorACL reconstruction has on the outcome of TKA. Wehypothesize that previous ACL reconstruction has anegative impact on the outcome of TKAwith respectto postoperative motion, outcome scores, need forrevision arthroplasty, and the incidence of infection.We also hypothesize that patients who underwentACL reconstruction with bone-patellar-bone allo-graft have an increased risk of patella baja after TKA.

Materials and Methods

Study Design

After approval by the institutional review board,patients were identified from a surgical database. Allpatients who underwent a reconstructive procedureof the ACL and later had a TKA performed at ourinstitution were included in the study. No patientswho had both procedures were excluded from thestudy group.

Table 1.

Type of ACLReconstruction

SurgicalTechnique

No. ofPatients

No. ofPatients withPatella Baja

Bone-patellartendon-bone autograft

Arthroscopic 7 0

Hamstring autograft Arthroscopic 9 3Primary ACL repair Open 5 0Type of graft unknown Unknown 15 1

1006 The Journal of Arthroplasty Vol. 23 No. 7 October 2008

Thirty-five patients who underwent 36 TKAsafter ACL reconstruction were identified. Range ofmotion, Knee Society Knee Score (KS), andFunctional Score (FS) were recorded at a pre-operative visit and at the most recent follow-up[10]. In addition, the type of ACL reconstruction,need for revision TKA surgery, and any diagnosisof infection were noted for each patient. The studygroup included 23 men and 12 women. One malepatient had bilateral TKA after bilateral ACLreconstructions.A cohort of control patients matched for patient

age, sex, surgeon, date, and implant that had notpreviously undergone ipsilateral knee surgery wereselected from our total joint registry. To increase thestatistical power of the study, 2 control patients wereidentified for each study patient. Only patients whounderwent primary TKA for the diagnosis ofdegenerative osteoarthritis were selected to serveas controls; patients with posttraumatic or inflam-matory arthritis were excluded. Revision kneearthroplasty surgery, diagnosis of infection, post-operative range of motion, KS and FS scores wererecorded for both the study and control groups.

Radiographic Assessment of Patella Baja

Radiographs for patients were reviewed, and theInsall-Salvati ratio was calculated [11]. Cases withan Insall-Salvati ratio of less than 0.8 were recordedas patella baja.

Arthroplasty Procedure

Previous incisions were incorporated into thesurgical exposure for TKA whenever possible. Theimplant used for TKA was selected by the surgeonat the time of arthroplasty procedure. All compo-nents used in this series were condylar designs;with 24 cruciate-sacrificing (posterior stabilized),9 cruciate-retaining, and 3 constrained-condylardesigns. In 34 of the knees, all components werecemented. In 1 knee, the tibial and femoralcomponents were uncemented, and another wasa hybrid design with a cemented femoral compo-nent and an uncemented tibial component. Nostems or augments were required. The patella wasresurfaced in all cases.

Statistical Analysis

Functional outcome measures, such as the KneeSociety Score, the Knee FS, extension, and flexion,recorded at the most recent follow-up (but before arevision of the TKA)were compared using a 2-samplet test assuming unequal variances. Revision estimates

were calculated using the Kaplan-Meier method.The Cox proportional hazards survival method,adjusting for correlated data, was used to assess theassociation between prior ACL reconstruction andsubsequent revision. Significance was defined as aP value less than .05 [12].

Results

The mean length of time from ACL reconstructionto TKA was 19.1 years (1.2-39.4 years). The meanage at the time of TKA was 53 years (29-78 years) inthe study group and 57 years (40-77 years) in thecontrol group. The mean follow-up after TKA toeither latest follow-up or subsequent revision in thestudy group was 45 months (2.0-239 months), andthe control group was 48 months (1.5-186 months).There were no references in any of the TKAoperative notes indicating increased technical diffi-culty due to previous reconstructive ligamentsurgery. No prosthetic augments or stems wererequired during the arthroplasty procedures.

Preoperatively, the mean loss of extension was 6°(0°-15°) and 5° (0°-30°) in the study group and thecontrol group, respectively (P = .42). The meanflexion was 101° (15°-135°) and 105° (55°-135°)(P = .36). The mean KS was 46 (6-85) and 53 (18-94) (P = .08). The mean FS was 68 (40-94) and 51(22-94) (P = .0001).

Postoperatively, the mean loss of extension was0.4 (−10, 6) and 0.6 (−6, 5) (P = .59) in thestudy group and the control group, respectively.Mean flexion was 105 (60-130) and 104 (50-130)(P = .71). Mean KS was 83 (30-99) and 89 (35-100)(P = .09), and the mean FS was 85 (40-100) and 80(20-100) (P = .31).

Two patients in the study group underwentrevision knee arthroplasty. One patient underwentrevision 6 months after index TKA for symptomaticinstability. The second patient underwent revisionat 13 years because of pain and osteolysis. Twopatients in the control group underwent revision.One patient was revised at 10 years because ofpolyethylene wear. A second patient developed

TKA Following ACL Reconstruction � Hoxie et al 1007

aseptic loosening and was revised at 15 years. Therisk of revision at 5 years was 3.7% (95% confidenceinterval [CI], 0-10.6) and 0%, and the risk of revisionat 10 years was 3.7% (95% CI, 0-10.6) and 8.3%(95%CI, 0-22.7) (P = .74) in the study group and thecontrol group, respectively.No patient in either group had periprosthetic

infection during the study period.A bone-patellar tendon-bone autograft recon-

struction technique was used in 7 patients in thestudy group. None of these patients showedradiographic findings of patella baja after TKA. Ofall the patients in the study group, 4 (11 %)demonstrated evidence of patella baja at mostrecent follow-up (Table 1). This finding waspresent in 2 (2.8%) patients in the control group(P = .18).

Discussion

Although the exact mechanism for joint degen-eration after ACL reconstruction is unclear at thepresent time, some patients who have undergoneACL reconstruction eventually require TKA. Pre-vious studies have evaluated the outcomes of TKAin patients who have undergone upper tibialosteotomy [13-16] and open reduction and internalfixation for tibial plateau fractures [17,18]. Thesestudies showed inferior results and higher rates ofcomplications when compared with historicalcohorts. The goal of this study was to evaluate theoutcomes of TKA after ACL reconstruction anddetermine if previous ACL surgery impacted thequality of the result. Using a matched cohort, wefound no statistically significant differences in theoutcomes studied between those who had under-gone previous ACL reconstruction and those whohad no knee surgery before the TKA.Patellar tendon shortening leading to patella baja

has been reported after ACL reconstruction [19-21].The overall rate of patella baja in this study was11%. However, no patient who underwent ACLreconstruction with bone-patellar tendon-boneautograft showed evidence of patella baja at mostrecent follow-up.Of interest was the finding that the average age of

these 36 patients was significantly younger (54years) at the time of their TKA than the averageage of all patients undergoing TKA at our institutionduring the same period (67 years). The exact cause ofearly degenerative arthritis requiring TKA in thisgroup could not be determined by this study. TheACL reconstructions performed on these patientswere done an average of 19 years before the TKAand

likely do not all reflect modern techniques of ACLreconstruction. Whether ACL reconstruction altersthe course of knee degeneration remains unknownand hopefully will be addressed in future studies.

Although the effect of ACL reconstruction on thedevelopment of knee osteoarthritis has not beenfully determined, it is clear from this study that ACLreconstruction does not markedly affect the resultsof TKA. There were no postoperative infections ineither the ACL or cohort groups, the postoperativerange of motion, knee society scores and rate ofrevision were similar, and there was no evidence forpatella baja in the 7 patients who had undergoneipsilateral bone-patellar tendon-bone harvest fortheir reconstruction.

The strength of this study is that it is a consecutiveseries with strict inclusion criteria andmatched case-control patients. The weaknesses are that it is aretrospective review, it is neither randomized norblinded, and the methods of ACL reconstructionutilized may not represent current surgical techni-ques in all cases.

The data obtained in this review indicate thatprior ACL reconstruction does not have a negativeeffect on subsequent TKA with respect to motion,outcome scores, rate of revision, or incidence ofinfection. There is no demonstrable increase inpatella baja after TKA in patients who previouslyhad an ipsilateral bone-patella tendon-bone graftharvested for ACL reconstruction.

References

1. Daniel DM, et al. Fate of the ACL-injured patient.A prospective outcome study. Am J Sports Med1994;22:632.

2. Miyasaka KC, Daniel D, Stone ML, et al. The incidenceof the anterior knee ligament injuries in the generalpopulation. Am J Knee Surg 1991;4:3.

3. Sherman MF, et al. A clinical and radiographicalanalysis of 127 anterior cruciate insufficient knees.Clin Orthop Relat Res 1988;227:229.

4. Smith FW, et al. Subjective functional assessmentsand the return to competitive sport after anteriorcruciate ligament reconstruction. Br J Sports Med2004;38:279.

5. Arnold MP, et al. The remains of anterior cruciateligament graft tension after cyclic knee motion. Am JSports Med 2005;33:536.

6. Harvey A, Thomas NP, Amis AA. Fixation of the graftin reconstruction of the anterior cruciate ligament.J Bone Joint Surg Br 2005;87:593.

7. Title CI, Rodriguez JA, Ranawat CS. Posterior cruciate-sacrificing versus posterior cruciate-substituting totalknee arthroplasty: a study of clinical and functionaloutcomes in matched patients. J Arthroplasty 2001;16:409.

1008 The Journal of Arthroplasty Vol. 23 No. 7 October 2008

8. Gill GS, Joshi AB. Long-term results of cemented,posterior cruciate ligament-retaining total knee arthro-plasty in osteoarthritis. Am J Knee Surg 2001;14:209.

9. Stern SH, Insall JN. Posterior stabilized prosthesis.Results after follow-up of nine to twelve years. J BoneJoint Surg Am 1992;74:980.

10. Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of theKnee Society clinical rating system. Clin Orthop 1989;248:13.

11. Insall J, Salvati E. Patella position in the normal kneejoint. Radiology 1971;101:101.

12. Therneau TM, Grambsch PM. Modeling survival dataextending the Cox model. 1st ed. New York: Springer;2000. p. 169.

13. Katz MM, et al. Results of total knee arthroplasty afterfailed proximal tibial osteotomy for osteoarthritis.J Bone Joint Surg Am 1987;69:225.

14. Madan S, Ranjith RK, Fiddian NJ. Total knee replace-ment following high tibial osteotomy. Bull Hosp Jt Dis2002;61:5.

15. Mont MA, et al. Total knee arthroplasty after failedhigh tibial osteotomy. A comparison with a matchedgroup. Clin Orthop Relat Res 1994:125.

16. Windsor RE, Insall JN, Vince KG. Technicalconsiderations of total knee arthroplasty after prox-imal tibial osteotomy. J Bone Joint Surg Am 1988;70:547.

17. Weiss NG, et al. Total knee arthroplasty in patientswith a prior fracture of the tibial plateau. J Bone JointSurg Am 2003;85-A:218.

18. Saleh KJ, et al. Total knee arthroplasty after openreduction and internal fixation of fractures of the tibialplateau: aminimum five-year follow-up study. J BoneJoint Surg Am 2001;83-A:1144.

19. Salmon LJ, et al. Long-term outcome of endoscopicanterior cruciate ligament reconstruction with patel-lar tendon autograft: minimum 13-year review. Am JSports Med 2006;34:721.

20. Jarvela T, et al. The incidence of patellofemoralosteoarthritis and associated findings 7 years afteranterior cruciate ligament reconstruction with abone-patellar tendon-bone autograft. Am J SportsMed 2001;29:18.

21. Muellner T, et al. Shortening of the patellar tendonafter anterior cruciate ligament reconstruction.Arthroscopy 1998;14:592.