Arthroscopy: The Journal of Arthroscopic and Related Surgery
Volume 26, Issue 2 , Pages 192-201, February 2010

The Effect of Medial Meniscectomy and Meniscal Allograft Transplantation on Knee and Anterior Cruciate Ligament Biomechanics

  • Jeffrey T. Spang, M.D.

      Affiliations

    • Department of Orthopaedics, University of North Carolina School of Medicine, Chapel Hill, North Carolina
    • ,
  • Alan B.C. Dang, M.D.

      Affiliations

    • Department of Orthopaedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut
    • ,
  • Augustus Mazzocca, M.D.

      Affiliations

    • Department of Orthopaedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut
    • ,
  • Lina Rincon, M.E.

      Affiliations

    • Department of Orthopaedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut
    • ,
  • Elifho Obopilwe, M.S.

      Affiliations

    • Department of Orthopaedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut
    • ,
  • Bruce Beynnon, Ph.D.

      Affiliations

    • Department of Orthopaedics & Rehabilitation, McClure Musculoskeletal Research Center, University of Vermont, Burlington, Vermont, U.S.A.
    • ,
  • Robert A. Arciero, M.D.

      Affiliations

    • Department of Orthopaedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut
    • Corresponding Author InformationAddress correspondence and reprint requests to Robert A. Arciero, M.D., New England Musculoskeletal Institute, University of Connecticut Health Center, 263 Farmington Ave, Farmington, CT 06030, U.S.A.

Received 14 June 2009; accepted 11 November 2009.

Article Outline

Purpose

Our purpose was to evaluate the effect of meniscectomy and meniscal allograft transplant on anterior cruciate ligament (ACL) and knee biomechanics.

Methods

A differential variable reluctance transducer was placed in the ACL of 10 human cadaveric knees to record strain. Tibial displacement from a neutral reference was recorded relative to the position of the femur. Testing was performed at 30°, 60°, and 90° of knee flexion. Six cycles of anterior-posterior loads were applied to the limit of 150 N. After a testing cycle, a medial meniscectomy was performed and the testing cycle was repeated. A meniscal allograft transplant was performed, and a final testing cycle was conducted. ACL strain and tibial displacement in the meniscectomy and meniscal allograft states were compared with the intact-knee state.

Results

Tibial displacement after meniscectomy significantly increased at all angles. The meniscal allograft transplant restored tibial displacement to normal values at 30° and 90°. ACL strain increased significantly after meniscectomy at 60° and 90° of flexion, and meniscal allograft transplant returned the strain values to normal at 60° and 90°.

Conclusions

In most cases medial meniscectomy produced a significant increase in tibial displacement relative to the femur, and meniscal allograft transplantation restored displacement values to normal. Meniscectomy increased ACL strain and meniscal allograft transplant restored strain values to normal in 2 of 3 tested flexion angles.

Clinical Relevance

The absence of the medial meniscus exposes the ACL to increased strain, whereas meniscal allograft lowered the strain on the native ACL. This could have implications for those patients undergoing ACL reconstruction who have concomitant removal of the medial meniscus.

 

The meniscus is a vital structure in the knee and contributes to stability and load transmission while increasing the weight-bearing surface area of the tibiofemoral joint.1, 2, 3, 4, 5, 6, 7, 8 Removal of the meniscus, in whole or in part, increases the contact stresses on the articular surface of the tibia.6, 7, 9, 10, 11 A greater respect for the importance of the meniscus has led to an increased interest in meniscal allograft transplant (MAT) procedures for the painful meniscus-deficient knee.12, 13

The importance of the meniscus as a restraint to anterior-posterior translation of the tibia relative to the femur in the anterior cruciate ligament (ACL)–deficient knee has been well documented.3, 4, 14 Incompetence of the ACL increases forces on the medial meniscus substantially15 and predisposes patients to meniscal tears.16, 17, 18 It has been proven that ACL reconstruction dramatically reduces strain on the menisci when compared with the cruciate-deficient knee.19 Papageorgiou et al.20 suggested that the interplay between the ACL and the meniscus is so substantial that loss of one of these structures could predispose the other to injury.

Patients undergoing ACL reconstruction often have concomitant meniscal pathology requiring some form of meniscectomy, with estimates ranging from 10% to 30%.17, 21 Long-term studies of patients who underwent ACL reconstruction have noted poorer clinical outcomes for those with combined meniscal and ACL pathology.22, 23 Authors have also hypothesized that a substantial meniscal deficiency may increase forces on the ACL graft, leading to secondary failure of an ACL reconstruction.22, 24 This has led some surgeons to aggressively treat combined deficiencies of the ACL and medial meniscus with reconstructive procedures addressing both deficiencies. In 2 retrospective clinical studies, researchers have reported good short-term clinical results with combined ACL reconstruction and MAT.25, 26

Existing studies that have focused on the biomechanical effects of meniscectomy on the knee have measured articular contact pressure, knee laxity, and ACL graft forces. A prior biomechanical study concluded that meniscectomy does not significantly change anterior tibial displacement in response to an applied anterior directed force,3 but this study did not evaluate the effect of meniscectomy on the biomechanics of the intact ACL. At least 1 in vivo study concluded that meniscectomy does not increase anterior-posterior displacement of the tibia relative to the femur. One recent study has examined the effect of meniscectomy on an ACL graft.20 Medial meniscectomy, plus an anterior directed tibial load, led to forces on an ACL graft that were 33% to 50% higher than the intact meniscus state depending on knee flexion angle.

Other authors have sought to understand the ACL biomechanics by measurement of its strain behavior. Beynnon and colleagues27, 28, 29, 30 have used differential variable reluctance transducers (DVRTs) implanted in the ACL to reliably measure strain in multiple testing situations in vitro and in vivo. Using methods described by Beynnon and colleagues,27 other authors have applied this measurement technique in the laboratory31 and in vivo32 to determine how ACL biomechanics are affected by knee loading. To date, little information exists regarding the state of the meniscus and its relation to ACL strain biomechanics.

Anecdotally, the senior author has observed the insidious onset of graft failure in technically sound ACL reconstructions in the face of medial meniscal deficiency. This observation is supported by some publications that note that deficiency of the medial meniscus negatively impacts the results of ACL reconstruction. Shelbourne and Gray22 showed greater laxity with KT-1000 arthrometer measurements (MEDmetric, San Diego, CA) after ACL reconstruction in patients who had undergone previous medial meniscectomy compared with knees with intact menisci. In addition, Garrett33 described a patient group with medial meniscal deficiency who underwent ACL reconstruction. The group with concomitant MAT had significantly improved KT-1000 arthrometer results compared with the group with isolated ACL reconstruction.

The primary purpose of this research was to evaluate the effect of meniscectomy and MAT on ACL and knee biomechanics. The primary hypothesis was that meniscectomy to include the posterior horn of the medial meniscus would result in increased strain on the native ACL whereas MAT would restore ACL strain values to normal. The secondary hypothesis was that neither meniscectomy nor MAT would significantly alter anterior displacement of the tibia relative to the femur in response to anterior loading when compared with the normal, intact knee.

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Methods 

Specimen Preparation 

Thirteen knee specimens were acquired through commercially active tissue banks. Initial radiographs were used to evaluate the specimens. Three specimens with severe arthritic changes on radiographs were rejected, leaving ten specimens available for testing. The mean age of the specimens was 56 years (range, 30 to 87 years). Seven male and three female specimens were included. Knee specimens were stored at −20°C but were thawed for an initial evaluation that included anterior-posterior and lateral radiographs with a standard 10-cm sizing device positioned at the joint line to allow correction for magnification. The mean weight of the donors was 149 lb (range, 88 to 224 lb). Specimens were refrozen until thawing 24 hours before testing. Meniscal allograft specimens for implantation were kept frozen at −20°C until thawing 12 hours before testing. Such freezing does not significantly affect the mechanical properties of ligaments.34

We removed all soft tissue 10 cm above and 8 cm below the joint line, leaving the overlying soft tissues surrounding the joint intact. The fibula was secured to the tibia in its anatomic position by use of a bone screw. The femur was potted in a 1.5-in-diameter (38-mm-diameter) cylinder of polyvinylchloride by use of polymethyl methacrylate to the level of the metaphyseal-diaphyseal flare. Three 5.0-mm stainless steel self-drilling and self-tapping Schantz pins (Synthes, Paoli, PA) were inserted in the midsagittal plane in an anterior-posterior direction on the crest of the tibia. After placement of the pins, the central canal of the tibia was filled with polymethyl methacrylate. Three large, open, adjustable external fixator clamps (Synthes) were used to secure an 11.0-mm carbon fiber bar (Synthes) 2 cm from the anterior crest of the tibia on the lateral side of the pins. Before specimen placement in the servohydraulic testing device, a medial parapatellar arthrotomy was performed. The fat pad was removed, with care taken to preserve the anterior meniscal horns and the intermeniscal ligament. A DVRT (2.0-mm ultra-microminiature sensor; MicroStrain, Burlington, VT) was then implanted in the anterior-medial bundle of the ACL. A notchplasty was performed to allow room for the DVRT and eliminate the possibility of impingement of the sensor against bone that potentially could occur at the limits of knee extension.

Testing System 

The testing fixture was designed to follow the main tenets of knee and cruciate ligament testing described by Beynnon and Amis.35 The femur was centered within an aluminum cylinder and secured with 4 screws. The femoral pot and all screws were marked to allow exact repositioning of the femur in the fixture after an intervention. The femur was attached to a calibrated platform and secured by 2 bearings that allowed rotation about the long axis of the femur. The calibrated platform could be adjusted and locked to allow knee flexion at 30°, 60°, and 90° relative to the tibia. The entire femoral construct was secured to a floating X-Y table that allowed unconstrained motion in the horizontal plane. The tibia was secured in neutral rotation directly to the actuator of the Materials Testing System (MTS) (model 858; MTS Systems, Eden Prairie, MN) by use of a large combination external fixator clamp (Synthes) such that it was perpendicular to the actuator's axis of movement. The actuator was centered just inferior to the tibiofemoral joint line at the center of the long axis of the tibia. Once fixed, the position of each clamp and bar was marked so that after an intervention, the tibia could be returned to the MTS in its original position and orientation. The actuator was free to rotate during testing. Anterior-posterior loads could be applied to the tibia while the combined fixtures allowed unconstrained superior-inferior and medial-lateral translation of the femur, internal/external rotation of the femur, and varus-valgus movement of the tibia.

The DVRT was placed in the anterior-medial bundle of the ACL before the tibia was secured to the actuator (Fig 1). The knee was taken through a range of motions to ensure DVRT output remained in the readable range. Once DVRT output was deemed satisfactory, a single loop of No. 4-0 nylon (Ethicon, Somerville, NJ) was placed in the ACL to secure the inferior pole of the DVRT. The tibia was then clamped to the MTS. A second stitch was placed in the anterior soft tissue to stabilize the DVRT wire. Once positioned, the tibia remained in place for testing at 30°, 60°, and 90° as the femur was adjusted. Anterior-posterior directed loads to the limit of 100 N were applied to the knee for 6 cycles at a rate of 0.25 Hz, and a force-displacement curve was recorded. The inflection point of the curve was used as the neutral point for testing and as the zero reference for recording displacement of the tibia relative to the femur.3 After this, anterior-posterior directed loads to the limit of 150 N were applied for 6 cycles. Force and displacement measures were recorded from the MTS machine while DVRT output was simultaneously recorded. A force-displacement curve was generated from the MTS data to confirm that the neutral reference point of the tibia had not changed and to record the maximal anterior displacement of the tibia in response to the anterior loading. A strain curve was produced with the force data from the MTS and the output data from the DVRT.

Strain was calculated by the approach described by Fleming et al.27 The zero-strain reference length (defined for calculations as L0) has been determined from the inflection point on the anterior-posterior loading–versus–DVRT output graph in prior studies.36 The inflection point of the graph has been identified by use of a graphical method in which a line is hand-drawn through the linear portion of the force-displacement curve and the relative inflection point is visually identified on the horizontal axis as L0. In an effort to eliminate the variability introduced by the judgment of investigators in determining the inflection point of the curve (L0), a mathematical equivalent to this method was created. Instead of visually identifying the linear portion of the force-displacement curve, we identified the data points that provided a linear regression line with r values greater than 0.95. Then, instead of defining L0 as the point at which the slope visually appears to change, we calculated the SD of the difference between the data points and our regression line. L0 was calculated as the first measured data point where the difference between the measured data and regression line exceeded 3 times the SD, which provided us with a 99% confidence limit that a change had occurred. These steps replicate the method of determining L0 by visual identification while providing improved precision and reducing observer bias (Fig 2).

A reproducibility test was undertaken before testing. This consisted of recording displacement from the MTS machine and strain measurements from the DVRT while cycling the knee at the selected angles. The recordings were taken after the knee was removed from the testing fixture and then repositioned in the fixture by replicating its original position. Displacement and strain were then re-recorded and compared with the original measures. Overall reproducibility was very good for both displacement and strain. For example, at 30° in the intact-knee state, the reproducibility trial showed a mean displacement of 9.3 ± 0.1 mm (95% confidence limit, 0.06) and strain was recorded at 4.33 ± 0.01 (95% confidence limit, 0.11).

After the initial test at 30°, knee flexion was adjusted to 60° and the testing process was repeated. Next, the knee was tested at 90° of flexion. After completion of 1 testing cycle (30°, 60°, and 90°), the specimen was removed and a total meniscectomy was performed through an open arthroscopically assisted technique. A 3-cm vertical arthrotomy was made immediately posterior to the medial collateral ligament to facilitate removal of the posterior horn.20 The arthrotomy was closed with 2 No. 2-0 FiberWire sutures (Arthrex, Naples, FL) with the knee in full extension to eliminate unnecessary capsular tightening before additional testing. By use of the femoral and tibial markings, we carefully replaced the knee in the MTS, making sure that both the tibia and femur exactly matched their original positions in the testing fixture. Testing was begun at 30° of knee flexion, and a complete testing cycle was repeated (30°, 60°, and 90°).

After the second testing cycle, the specimen was removed and a medial meniscal allograft was performed through the Dovetail bone-block technique (Arthrex). We requested meniscal allografts from the tissue providers using the sizing protocol described by Pollard et al.37 Because of the limited availability of meniscal allografts, variations in size up to 3 mm from the recorded width of the tibial plateau (taken from the anterior-posterior radiograph) were accepted. The mean difference between the medial-lateral measure of the knee and the allograft was 1.38 mm (range, 0 to 3 mm) (Fig 3A).

A standard surgical approach to the medial meniscus through the arthrotomy allowed a simulated in vivo procedure for MAT.38 The posterior horn of the allograft was stabilized with 2 No. 2-0 FiberWire stitches (Arthrex) placed in the allograft to facilitate graft insertion that were then tied over the capsule (Fig 3B). Two additional arthroscopically placed No. 2-0 FiberWire double-loaded meniscal repair needles were placed in a vertical fashion and tied over the medial capsule to stabilize the midportion of the graft. Two No. 2-0 FiberWire vertical stitches were placed into the anterior meniscal-synovial border through the arthrotomy. In this fashion 6 total stabilization stitches were placed. Once the meniscal allograft was completed, the specimen was replaced in the MTS device, and the testing cycles were completed for a third time (30°, 60°, and 90°) (Fig 4).

  • View full-size image.
  • Figure 4. 

    (A) View from notch of posterior-medial tibia and femur after arthroscopically assisted meniscectomy. (B) View from notch of posterior-medial tibia and femur after MAT.

Data recorded included ACL strain and anterior displacement of the tibia relative to the initial reference/zero position for each specimen condition (intact, meniscectomy, and MAT) at each knee flexion angle. Two outcomes were analyzed: ACL strain and tibial displacement. The independent variables were flexion angle (30°, 60°, and 90°) and knee condition (intact, meniscectomy, and MAT). A multivariate, random-intercept regression model was fitted for each outcome by use of SAS software, version 8.02 (SAS, Cary, NC). This technique properly accounts for the repeated measures on the same specimens.

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Results 

Strain 

Anterior directed loading of the intact knee at 30° to the limit of 150 N produced a strain (%) of 3.77 ± 0.54 (Fig 5). With the meniscus removed, strain (%) increased to 4.56 ± 0.60, but this difference was not significant (P = .20). After MAT, strain (%) decreased to 4.14 ± 0.60. This was also not significantly different from the intact state (P = .54).

Anterior directed loading at 60° in the intact knee produced a strain (%) of 3.90 ± 0.44. Removal of the meniscus significantly increased the strain (%) with anterior tibial loading to 4.99 ± 0.42 (P = .02). MAT lowered the strain (%) to 4.23 ± 0.42, but this was not significantly different in comparison to the intact state (P = .45).

With an applied load at 90°, the strain (%) in the ACL in the intact state was 3.99 ± 0.49, whereas removal of the meniscus significantly increased the strain (%) to 5.12 ± 0.45 (P = .02). Replacement of the meniscus with MAT decreased the strain (%) to 4.34 ± 0.45, which was not significantly different from the strain (%) in the intact state (P = .45).

Displacement 

Anterior directed loading of the intact knee at 30° to the limit of 150 N produced, on average, 9.6 ± 0.6 mm of anterior displacement of the tibia, and removal of the meniscus produced a significant increase in the anterior translation to 10.6 ± 0.2 mm (P = .01) (Fig 6). After MAT, anterior displacement of the tibia decreased to 10.1 ± 0.2 mm, and this was not different in comparison to the intact condition (P = .12).

Anterior tibial translation measured at 60° in response to a 150-N load was 6.1 ± 0.5 mm in the intact state. Anterior tibial translation increased after meniscectomy to 7.2 ± 0.2 mm. The difference between the intact and meniscectomy states was significant (P < .01). After MAT, anterior directed loading produced 6.5 ± 0.2 mm of anterior displacement of the tibia, which was significantly different from the intact state (P = .04).

Anterior directed loading of the intact knee at 90° to the limit of 150 N produced, on average, 4.1 ± 0.4 mm of anterior displacement of the tibia, and removal of the meniscus produced a significant increase in the anterior translation to 5.1 ± 0.2 mm (P < .01). MAT decreased the anterior tibial translation produced by the 150-N loading to 4.4 ± 0.2 mm, which was not significantly different from the intact state (P = .07).

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Discussion 

In this investigation we examined the effect of meniscectomy and MAT on the biomechanics of the ACL and knee. We combined a well-described method for measuring ACL strain27 with a test fixture that was designed to meet the standards of previously described ligament and knee testing procedures.35 This combination allowed us to reliably record the effects of our 2 treatments (meniscectomy and MAT) and compare them with the intact condition.

In this study we determined that removal of the meniscus led to a significant increase in anterior tibial translation at all knee flexion angles. This is in contrast to the most widely cited study of the effect of meniscectomy on the biomechanics of the normal knee, by Warren and colleagues,3 in which no increase in tibial displacement was noted after complete medial meniscectomy. These divergent findings may be explained by differences in the methods used; the earlier study measured displacement in response to an anterior directed load of 100 N, whereas in our study a 150-N load limit was used. In addition, differences in mounting and fixation methods, materials testing devices, and data collection methods may possibly have led to different outcomes when comparing these 2 studies.

When examining the potential biomechanical effects of MAT on tibial translation, we found no significant differences in the anterior tibial translation between the intact knee and the knee after MAT at 30° and 90° of knee flexion. MAT decreased the anterior tibial translations and restored them to within the limits of normal, and this was a consistent improvement that was observed across all specimens in comparison to the meniscectomy state. At 60° of knee flexion, MAT did reduce tibial displacement, but the difference in displacement remained statistically different when compared with the intact state. In the study reported by Papageorgiou et al.,20 the greatest increase of forces on the ACL graft after meniscectomy was noted at 60° of knee flexion. This suggests that the meniscus may be more involved with resisting tibial displacement at this flexion angle than at the other flexion angles tested. This may explain our unique finding at 60° that MAT did not return displacement to normal intact values. Our secondary hypothesis was partially supported, because meniscectomy did increase tibial translation significantly whereas MAT restored translation to within the limits of normal at 2 of 3 flexion angles.

At 30° of knee flexion, there was no significant difference between ACL strain values in the intact state and the meniscectomy state or in the intact state and the MAT state. MAT did decrease the ACL strain values in comparison to the meniscectomy state, returning them closer to those observed for the intact knee.

At both 60° and 90° of knee flexion, meniscectomy produced a significant increase in ACL strain values. Strain values increased by approximately one-third at both flexion angles. These increases were considered to represent significant changes when compared with the intact condition. MAT was successful in restoring the ACL strain values to the normal, intact condition. When compared with the intact condition, the ACL strain values after MAT were approximately one-tenth greater at 60° and 90° of flexion. The higher strains after MAT were not statistically different from the intact-state strains. Our primary hypothesis was validated because we noted increased strain ACL values after meniscectomy and restoration of these strain values to normal after MAT at 2 of 3 knee flexion angles.

The complex relation between the ACL and the medial meniscus has been examined by other authors. It is accepted that the medial meniscus becomes an important restraint to anterior tibial displacement in the ACL-deficient knee.3, 14 Hollis et al.19 showed conclusively that removal of the ACL increased strain on the medial meniscus and that an ACL reconstruction returned the strain in the meniscus to levels that were similar to the intact knee. Papageorgiou et al.20 further investigated the relation between an ACL graft and the meniscus by performing a meniscectomy in the ACL-reconstructed knee and measuring the change in forces on the ACL graft. They noted a dramatic increase in force on the ACL graft after meniscectomy. Clinically, authors have noted the need to carefully examine secondary factors (alignment and secondary ligamentous restraints) when presented with a failed ACL graft.39, 40 Other authors have suggested that the status of the meniscus may be another important factor to consider when planning ACL revision surgery.41, 42 Our results, in combination with the study of Papageorgiou et al., provide a biomechanical basis for this clinical supposition. Some of these authors have reported favorable clinical results with combined ACL reconstruction and MAT, although the studies are retrospective in nature and have small patient populations.26, 43

To date, biomechanical meniscal allograft research has focused on the ability of meniscal allografts to restore normal contact pressures to the knee.44, 45, 46 Given the improved long-term results reported with meniscal allograft12, 13, 25, 47, 48 and the increasing frequency of ACL revision surgery, the patient presenting with ACL graft failure and meniscal deficiency may be a candidate for meniscal allograft and ACL reconstruction. This may be especially pertinent for the patient with insidious recurrence of knee instability after what appears to be a technically sound ACL reconstruction and medial meniscal deficiency.

To our knowledge, this is the first attempt to quantify the effects of MAT on ACL strain in combination with tibial translation. Several weaknesses are associated with our study. We chose to limit our measurement approach to a single DVRT placed on the anteromedial bundle of the ACL. It is clear that the ACL has a strain distribution; however, we only measured 1 aspect of this distribution. It is possible that measurement of a different aspect of the ACL strain distribution may have produced different findings. For example, the strain biomechanics of the posterolateral bundle of the ACL with the knee near extension may be very different in comparison to the anteromedial bundle. Consequently, meniscectomy and MAT may have had a very different effect on the biomechanics of the posterolateral aspect of the ACL.49 We used a bone-block technique for the MAT, which some authors think allows easier insertion and maintenance of the anatomic relation between the allograft horns,50, 51, 52 whereas proponents of the bone-plug technique note that ACL fibers remain undisturbed and minor modifications of the MAT may allow a better donor-recipient fit.50, 53, 54 Using the bone-block technique, we may have altered the native ACL insertion, which could have affected the final DVRT readings for the final testing state. Although every attempt was made to size match the allografts by use of commonly applied clinical techniques, variability in available meniscal allografts may have led to suboptimal meniscal allograft sizing, which could have had an effect on post-MAT testing. The possibility exists that an excessively large MAT could have acted as a “bumper” and thus affected measured outcomes. Our testing did not include an applied axial compressive load. Prior work has shown that axially loading the knee in vivo can increase ACL strain, but we cannot predict how our results would vary if an axial load was introduced into our model.55 Future research in this area should consider inclusion of an axial compressive load to the joint. In addition, our statistical measures may not directly correlate to clinically significant measures. As noted in our results, small changes (<2 mm) were noted in displacement testing between knee states and the clinical importance of such small differences cannot be predicted. We did not conduct a formal post hoc power analysis, although we can assume that additional specimens may have increased statistical power. Lastly, we did not evaluate how applied internal and external torque about the long axis of the tibia would affect our results. Because these torques are known to affect ACL strain biomechanics, future research is indicated in this area. It should be noted that we tested the kinematics of medial meniscectomy and MAT on the normal ACL. The effect of meniscal resection and MAT on the biomechanics of an ACL graft could be very different and is the subject of future research.

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Conclusions 

In most cases medial meniscectomy produced a significant increase in tibial displacement relative to the femur, and meniscal allograft transplantation restored displacement values to normal. Meniscectomy increased ACL strain and MAT restored strain values to normal in 2 of 3 tested flexion angles.

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Supplementary data 

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Supplementary data.

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References 

  1. Fairbank T. Knee joint changes after meniscectomy. J Bone Joint Surg Am. 1948;30:664–670
  2. Hsieh HH, Walker PS. Stabilizing mechanisms of the loaded and unloaded knee joint. J Bone Joint Surg Am. 1976;58:87–93
  3. Levy IM, Torzilli PA, Warren RF. The effect of medial meniscectomy on anterior-posterior motion of the knee. J Bone Joint Surg Am. 1982;64:883–888
  4. Markolf KL, Mensch JS, Amstutz HC. Stiffness and laxity of the knee—The contributions of the supporting structures (A quantitative in vitro study). J Bone Joint Surg Am. 1976;58:583–594
  5. Bargar WL, Moreland JR, Markolf KL, Shoemaker SC, Amstutz HC, Grant TT. In vivo stability testing of post-meniscectomy knees. Clin Orthop Relat Res. 1980;247–252
  6. Ihn JC, Kim SJ, Park IH. In vitro study of contact area and pressure distribution in the human knee after partial and total meniscectomy. Int Orthop. 1993;17:214–218
  7. Lee SJ, Aadalen KJ, Malaviya P, et al. Tibiofemoral contact mechanics after serial medial meniscectomies in the human cadaveric knee. Am J Sports Med. 2006;34:1334–1344
  8. Fukubayashi T, Kurosawa H. The contact area and pressure distribution pattern of the knee (A study of normal and osteoarthrotic knee joints). Acta Orthop Scand. 1980;51:871–879
  9. Baratz ME, Fu FH, Mengato R. Meniscal tears: The effect of meniscectomy and of repair on intraarticular contact areas and stress in the human knee (A preliminary report). Am J Sports Med. 1986;14:270–275
  10. Krause WR, Pope MH, Johnson RJ, Wilder DG. Mechanical changes in the knee after meniscectomy. J Bone Joint Surg Am. 1976;58:599–604
  11. Kurosawa H, Fukubayashi T, Nakajima H. Load-bearing mode of the knee joint: Physical behavior of the knee joint with or without menisci. Clin Orthop Relat Res. 1980;283–290
  12. Cole BJ, Dennis MG, Lee SJ, et al. Prospective evaluation of allograft meniscus transplantation: A minimum 2-year follow-up. Am J Sports Med. 2006;34:919–927
  13. Verdonk PC, Verstraete KL, Almqvist KF, et al. Meniscal allograft transplantation: Long-term clinical results with radiological and magnetic resonance imaging correlations. Knee Surg Sports Traumatol Arthrosc. 2006;14:694–706
  14. Shoemaker SC, Markolf KL. The role of the meniscus in the anterior-posterior stability of the loaded anterior cruciate-deficient knee (Effects of partial versus total excision). J Bone Joint Surg Am. 1986;68:71–79
  15. Allen CR, Wong EK, Livesay GA, Sakane M, Fu FH, Woo SL. Importance of the medial meniscus in the anterior cruciate ligament-deficient knee. J Orthop Res. 2000;18:109–115
  16. Warren RF, Levy IM. Meniscal lesions associated with anterior cruciate ligament injury. Clin Orthop Relat Res. 1983;32–37
  17. Wickiewicz TL. Meniscal injuries in the cruciate-deficient knee. Clin Sports Med. 1990;9:681–694
  18. Thompson WO, Fu FH. The meniscus in the cruciate-deficient knee. Clin Sports Med. 1993;12:771–796
  19. Hollis JM, Pearsall AW IV, Niciforos PG. Change in meniscal strain with anterior cruciate ligament injury and after reconstruction. Am J Sports Med. 2000;28:700–704
  20. Papageorgiou CD, Gil JE, Kanamori A, Fenwick JA, Woo SL, Fu FH. The biomechanical interdependence between the anterior cruciate ligament replacement graft and the medial meniscus. Am J Sports Med. 2001;29:226–231
  21. Poehling GG, Ruch DS, Chabon SJ. The landscape of meniscal injuries. Clin Sports Med. 1990;9:539–549
  22. Shelbourne KD, Gray T. Results of anterior cruciate ligament reconstruction based on meniscus and articular cartilage status at the time of surgery (Five- to fifteen-year evaluations). Am J Sports Med. 2000;28:446–452
  23. Wu WH, Hackett T, Richmond JC. Effects of meniscal and articular surface status on knee stability, function, and symptoms after anterior cruciate ligament reconstruction: A long-term prospective study. Am J Sports Med. 2002;30:845–850
  24. Johnson DL, Harner CD, Maday MG, et al. Revision anterior cruciate ligament surgery. In:  Fu FH editors. Knee surgery. Baltimore: Williams & Wilkins; 1994;p. 877–895
  25. Graf KW, Sekiya JK, Wojtys EM. Long-term results after combined medial meniscal allograft transplantation and anterior cruciate ligament reconstruction: Minimum 8.5-year follow-up study. Arthroscopy. 2004;20:129–140
  26. Yoldas EA, Sekiya JK, Irrgang JJ, Fu FH, Harner CD. Arthroscopically assisted meniscal allograft transplantation with and without combined anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2003;11:173–182
  27. Fleming BC, Beynnon BD, Tohyama H, et al. Determination of a zero strain reference for the anteromedial band of the anterior cruciate ligament. J Orthop Res. 1994;12:789–795
  28. Howe JG, Wertheimer C, Johnson RJ, Nichols CE, Pope MH, Beynnon B. Arthroscopic strain gauge measurement of the normal anterior cruciate ligament. Arthroscopy. 1990;6:198–204
  29. Beynnon BD, Pope MH, Wertheimer CM, et al. The effect of functional knee-braces on strain on the anterior cruciate ligament in vivo. J Bone Joint Surg Am. 1992;74:1298–1312
  30. Fleming BC, Beynnon BD, Nichols CE, Johnson RJ, Pope MH. An in vivo comparison of anterior tibial translation and strain in the anteromedial band of the anterior cruciate ligament. J Biomech. 1993;26:51–58
  31. Withrow TJ, Huston LJ, Wojtys EM, Ashton-Miller JA. The relationship between quadriceps muscle force, knee flexion, and anterior cruciate ligament strain in an in vitro simulated jump landing. Am J Sports Med. 2006;34:269–274
  32. Cerulli G, Benoit DL, Lamontagne M, Caraffa A, Liti A. In vivo anterior cruciate ligament strain behaviour during a rapid deceleration movement: Case report. Knee Surg Sports Traumatol Arthrosc. 2003;11:307–311
  33. Garrett J. Meniscal transplantation. In:  Aichroth P editors. Knee surgery: Current practice. London: Martin Dunitz Ltd; 1992;
  34. Woo SL, Orlando CA, Camp JF, Akeson WH. Effects of postmortem storage by freezing on ligament tensile behavior. J Biomech. 1986;19:399–404
  35. Beynnon BD, Amis AA. In vitro testing protocols for the cruciate ligaments and ligament reconstructions. Knee Surg Sports Traumatol Arthrosc. 1998;6(Suppl 1):S70–S76
  36. Beynnon BD, Fleming BC. Anterior cruciate ligament strain in-vivo: A review of previous work. J Biomech. 1998;31:519–525
  37. Pollard ME, Kang Q, Berg EE. Radiographic sizing for meniscal transplantation. Arthroscopy. 1995;11:684–687
  38. Medvecky MJ, Noyes FR. Surgical approaches to the posteromedial and posterolateral aspects of the knee. J Am Acad Orthop Surg. 2005;13:121–128
  39. George MS, Dunn WR, Spindler KP. Current concepts review: Revision anterior cruciate ligament reconstruction. Am J Sports Med. 2006;34:2026–2037
  40. Carson EW, Anisko EM, Restrepo C, Panariello RA, O'Brien SJ, Warren RF. Revision anterior cruciate ligament reconstruction: Etiology of failures and clinical results. J Knee Surg. 2004;17:127–132
  41. Allen CR, Griffin JR, Harner CD. Revision anterior cruciate ligament reconstruction. Orthop Clin North Am. 2003;34:79–98
  42. Rodeo SA. Meniscal allografts: State of the art. In: 2007 AOSSM Allograft Workshop. Rosemont, IL: American Orthopaedic Society for Sports Medicine; 2007;p. 5–31
  43. Sekiya JK, Giffin JR, Irrgang JJ, Fu FH, Harner CD. Clinical outcomes after combined meniscal allograft transplantation and anterior cruciate ligament reconstruction. Am J Sports Med. 2003;31:896–906
  44. Paletta GA, Manning T, Snell E, Parker R, Bergfeld J. The effect of allograft meniscal replacement on intraarticular contact area and pressures in the human knee (A biomechanical study). Am J Sports Med. 1997;25:692–698
  45. Alhalki MM, Hull ML, Howell SM. Contact mechanics of the medial tibial plateau after implantation of a medial meniscal allograft (A human cadaveric study). Am J Sports Med. 2000;28:370–376
  46. Dienst M, Greis PE, Ellis BJ, Bachus KN, Burks RT. Effect of lateral meniscal allograft sizing on contact mechanics of the lateral tibial plateau: An experimental study in human cadaveric knee joints. Am J Sports Med. 2007;35:34–42
  47. Noyes FR, Barber-Westin SD, Rankin M. Meniscal transplantation in symptomatic patients less than fifty years old. J Bone Joint Surg Am. 2005;87(Suppl 1):149–165
  48. Rueff D, Nyland J, Kocabey Y, Chang HC, Caborn DN. Self-reported patient outcomes at a minimum of 5 years after allograft anterior cruciate ligament reconstruction with or without medial meniscus transplantation: An age-, sex-, and activity level-matched comparison in patients aged approximately 50 years. Arthroscopy. 2006;22:1053–1062
  49. Zantop T, Herbort M, Raschke MJ, Fu FH, Petersen W. The role of the anteromedial and posterolateral bundles of the anterior cruciate ligament in anterior tibial translation and internal rotation. Am J Sports Med. 2007;35:223–227
  50. Alford W, Cole BJ. The indications and technique for meniscal transplant. Orthop Clin North Am. 2005;36:469–484
  51. Farr J, Meneghini RM, Cole BJ. Allograft interference screw fixation in meniscus transplantation. Arthroscopy. 2004;20:322–327
  52. Khetia EA, McKeon BP. Meniscal allografts: Biomechanics and techniques. Sports Med Arthrosc. 2007;15:114–120
  53. Berlet GC, Fowler PJ. The anterior horn of the medical meniscus (An anatomic study of its insertion). Am J Sports Med. 1998;26:540–543
  54. Kohn D, Moreno B. Meniscus insertion anatomy as a basis for meniscus replacement: A morphological cadaveric study. Arthroscopy. 1995;11:96–103
  55. Fleming BC, Renstrom PA, Beynnon BD, et al. The effect of weightbearing and external loading on anterior cruciate ligament strain. J Biomech. 2001;34:163–170

 Supported by the Orthopaedic Research and Education Foundation, Arthrex, and AlloSource. The authors report no conflict of interest.

PII: S0749-8063(09)00952-9

doi:10.1016/j.arthro.2009.11.008

Arthroscopy: The Journal of Arthroscopic and Related Surgery
Volume 26, Issue 2 , Pages 192-201, February 2010