Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation

Journal of Orthopaedic Science xxx (xxxx) xxx

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Original Article

Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation Takaaki Hiranaka a, Takayuki Furumatsu a, *, Yusuke Kamatsuki a, Kazuhisa Sugiu a, Yoshiki Okazaki a, Shin Masuda a, Yuki Okazaki a, Shota Takihira a, Shinichi Miyazawa b, Eiji Nakata c, Toshifumi Ozaki a a Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikatacho, Kitaku, Okayama 700-8558, Japan b Department of Intelligent Orthopaedic System Development, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 25-1 Shikatacho, Kitaku, Okayama 700-8558, Japan c Department of Musculoskeletal Traumatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikatacho, Kitaku, Okayama 700-8558, Japan

a r t i c l e i n f o

a b s t r a c t

Article history: Received 17 January 2019 Received in revised form 13 June 2019 Accepted 4 August 2019 Available online xxx

Background: Several studies have demonstrated that posttraumatic knee osteoarthritis progresses even after anterior cruciate ligament reconstruction. Few reports described zone-specific cartilaginous damages after anterior cruciate ligament reconstruction. This study aimed to compare the status of articular cartilage at anterior cruciate ligament reconstruction with that at second-look arthroscopy. Methods: This study included 20 patients (20 knees, 10 males and 10 females, mean age 22.4 years, Body mass index 24.4 kg/m2) that underwent arthroscopic anatomic double-bundle anterior cruciate ligament reconstruction and second-look arthroscopy. Mean periods from injury to reconstruction and from reconstruction to second-look arthroscopy were 3.4 and 15.3 months, respectively. Cartilage lesions were evaluated arthroscopically in the 6 articular surfaces and 40 articular subcompartments independently, and these features were graded with the International Cartilage Repair Society articular cartilage injury classification; comparisons were made between the grades at reconstruction and at second-look arthroscopy. Furthermore, clinical outcomes were assessed at reconstruction and at second-look arthroscopy, using the Lysholm knee score, Tegner activity scale, International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, side-to-side difference of the KT-2000 arthrometer, and pivot shift test. Results: Each compartment showed a deteriorated condition at second-look arthroscopy compared with the pre-reconstruction period. A significant worsening of the articular cartilage was noted in all compartments except the lateral tibial plateau and was also observed in the central region of the medial femoral condyle and trochlea after reconstruction. However, each clinical outcome was significantly improved postoperatively. Conclusions: Good cartilage conditions were restored in most subcompartments at second-look arthroscopy. Furthermore, posttraumatic osteoarthritic changes in the patellofemoral and medial compartments progressed even in the early postoperative period, although good knee stability and clinical outcomes were obtained. Care is necessary regarding the progression of osteoarthritis and the appearance of knee symptoms in patients undergoing anterior cruciate ligament reconstruction. © 2019 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

1. Introduction * Corresponding author. Fax: þ81 86 223 9727. E-mail address: [email protected] (T. Furumatsu).

Anterior cruciate ligament (ACL) injuries lead to posttraumatic knee osteoarthritis by inducing abnormal kinematics of the knee.

https://doi.org/10.1016/j.jos.2019.08.001 0949-2658/© 2019 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Please cite this article as: Hiranaka T et al., Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation, Journal of Orthopaedic Science, https://doi.org/10.1016/j.jos.2019.08.001

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T. Hiranaka et al. / Journal of Orthopaedic Science xxx (xxxx) xxx

ACL reconstruction (ACLR) can reduce excessive mechanical stress on articular cartilage and meniscus by restoring knee stability. However, several studies demonstrate that posttraumatic knee osteoarthritis progresses even after ACLR [1,2]. Secondary prevention strategies to delay osteoarthritis onset after an injury are essential. Unlike established radiographic osteoarthritis, the trajectory of the early pre-radiographic stages of the disease, such as posttraumatic changes to cartilage and bone marrow, can be modified [3]. Recently, magnetic resonance imaging (MRI) techniques have proven useful in detecting early structural changes in all joint tissues. MRI studies revealed progressive degeneration in the patellofemoral (PF) or medial tibiofemoral (TF) cartilage in ACLreconstructed knees about 2 years after reconstruction, which may be related with longer-term radiographic osteoarthritis [4,5]. However, radiographically invisible pathologies such as cartilage defects and meniscal tears can also be visualized by arthroscopy. Arthroscopy, with its tactile and dynamic capabilities, permits the palpation of joint tissues with a probe, allowing the detection of degenerative change. Few reports have been published about early cartilage change after ACLR using arthroscopy [6]. Hence, the purpose of this study was to evaluate the site-specific changes in cartilage status after double-bundle ACLR using arthroscopy. We hypothesized that degenerative change would progress in specific subcompartments in the PF or medial TF cartilage early after ACLR via arthroscopy. 2. Materials and methods This study was approved by our Institutional Review Board and written informed consent was obtained from all included patients. From 2014 to 2017, 68 knees that underwent a double-bundle ACLR were examined. Six patients who had not yet undergone secondlook arthroscopy and a patient who underwent revision surgery were excluded from the study. We also excluded 41 patients with a meniscal injury at reconstruction because meniscal injury is one of the major osteoarthritis risk factors. Overall, 20 knees (20 patients) were enrolled in this study. The variety of sports patients did included basketball in case of 7 knees, football in 4 knees, badminton in 3 knees, and 2 knees each in fighting sports, skiing, and volleyball. Seventeen knees had the bone bruise at preoperative MRI. The area of the bone bruise was recognized at lateral femoral condyle (LFC) compartments in 11 knees, lateral tibial plateau (LTP) in 2 knees, LFC and LTP in 2 knees and LFC and medial femoral condyle (MFC) in 2 knees. There were no cases of multiple ligament injury. Patient demographics are shown in Table 1. 2.1. Surgical technique Arthroscopic double-bundle ACLRs were performed, using hamstring tendon autografts for all patients [7,8]. The femoral and

Table 1 Patient demographics. Range Cases (knees) Gender (male: female) Age (years) Height (m) Weight (kg) Body mass index (kg/m2) Duration (months) from injury to reconstruction from reconstruction to second-look from injury to second-look

20 10 : 10 22.4 ± 6.7 1.67 ± 0.08 68.1 ± 13.6 24.4 ± 3.4

15.0e39.0 1.56e1.83 47.2e101.0 19.4e30.2

3.4 ± 35. 15.3 ± 60. 18.6 ± 7.2

1e15 8e32 10e36

Data of age, height, weight, body mass index, and durations are presented as a mean ± standard deviation.

tibial bone tunnels were created using an outside-in technique within the ACL footprints as previously described [9e11]. The mean diameter of the anteromedial (AM) bundle was 5.7 mm (range 5.0e6.0 mm) and of the mean posterolateral (PL) bundle was 4.9 mm (range 4.5e5.0 mm). The mean length of the femoral tunnel for the AM bundle was 38.6 mm (range 30e49 mm) and for the PL bundle was 37.3 mm (range 28e44 mm). Femoral fixation was achieved using the TightRope (Arthrex, Naples, FL, USA) or Endobutton system (Smith & Nephew Inc., Andover, MA, USA) [12e14]. Tibial fixation was performed with the knee flexed at 20 using double-spike plates (Meira, Aichi, Japan), with an initial tension of 20 N for the PL bundle and 30 N for the AM bundle [10,15]. The tension in each bundle was independently measured using a tensiometer. We used the surgical option for cartilage damage separately. Either debridement or the untreated option was selected for the relatively mild cartilage damages like International Cartilage Repair Society (ICRS) grade 1 to 3 [16]. And bone marrow stimulation such as microfracture or drilling was used for severe cartilage damages like in the case of ICRS grade 4.

2.2. Postoperative rehabilitation protocols All patients wore a knee brace for 1 week to promote initial healing of the graft, fixation points, and affected soft tissue. Knee range of motion exercises and partial weight bearing were initiated in the postoperative week 2. Full weight bearing was permitted at 1 month, running at 5 months, and a return to sports at 8 months postoperatively [9,17,18].

2.3. Evaluation of clinical and radiological outcomes During the follow-up examinations, the Lysholm score, Tegner activity scale, Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) knee examination form, side-to-side difference of KT-2000, and pivot shift test were obtained as the clinical outcomes. KellgrenLawrence (KL) grade was also evaluated independently as the radiological outcome by two orthopedic surgeons blinded to the procedures. All measurements were compared between reconstruction and second-look arthroscopy.

2.4. Evaluation of cartilage injury Cartilage injury was independently evaluated via arthroscopy in the six compartments comprising the patella, trochlea, MFC, LFC, medial tibial plateau (MTP), and LTP (Fig. 1a). The patella, MFC, and LFC were each subdivided into 9 subcompartments, MTP and LTP were each subdivided into 5 subcompartments, and the trochlea was subdivided into 3 subcompartments. Chondral injury at reconstruction and at second-look arthroscopy was compared in the 40 subcompartments (Fig. 1b). Each subcompartment was evaluated according to the modified ICRS articular cartilage injury classification which combined the subclassification in each grade together and used as the point-addition scoring system. The same score, as evaluated in the ICRS grade, was given to the subcompartment. Each compartment score was calculated as the sum of all subcompartment scores belonging to the compartment for semi-quantitative evaluation. Two orthopedic surgeons independently evaluated the cartilage status at reconstruction and at second-look arthroscopy. Every assessment was performed using video of arthroscopy. Each observer performed each evaluation twice, at least 2 weeks apart.

Please cite this article as: Hiranaka T et al., Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation, Journal of Orthopaedic Science, https://doi.org/10.1016/j.jos.2019.08.001

T. Hiranaka et al. / Journal of Orthopaedic Science xxx (xxxx) xxx

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2.5. Statistical analysis

3.2. Cartilage grade of each compartment

Statistical analysis was performed using EZR (Saitama Medical Center Jichi Medical University, Saitama, Japan). A paired t-test was used to compare pre- and postoperative data of the Lysholm score, IKDC score, KOOS, and side-to-side difference of KT-2000. Wilcoxon's signed-rank test was used to compare the subcompartment score, compartment score, and Tegner activity scale between reconstruction and second-look arthroscopy. Statistical significance was set as p < 0.05. The inter-observer and intra-observer reliabilities were assessed with the intraclass correlation coefficient (ICC), with ICC > 0.83 considered reliable measurement.

The inter-observer and intra-observer reliabilities were considered high, with mean ICC values of 0.92 and 0.94, respectively. The score of each compartment is shown in Table 3. Each compartment showed a deteriorated condition at second-look arthroscopy compared with the pre-reconstruction state. Significant worsening was noted in the patella, trochlea, MFC, MTP, and LFC compartments (p ¼ 0.019, 0.019, 0.005, 0.048, and 0.022, respectively).

3. Results 3.1. Clinical and radiographic outcomes The average Lysholm score, average IKDC score, average KOOS, median Tegner activity scale, average side-to-side difference of KT-2000, and positive pivot shift test were all significantly improved at second-look arthroscopy (reconstruction vs. secondlook arthroscopy: 84.8 vs. 97.4, 63.4 vs. 89.0, 81.6 vs. 94.4, 4 vs. 6, 3.6 mm vs. 0.8 mm, and 20 vs. 0 respectively). Eighteen knees had KL grade 0 and 2 knees had KL grade 1 both at reconstruction and at second-look arthroscopy (Table 2). No knees had meniscal injuries at second-look arthroscopy. Additionally, no cases required treatment for the cartilage at reconstruction. At second-look arthroscopy, microfracture was performed for ICRS grade 4 cartilage damage at the T 2 subcompartment in one case. No cases needed special treatment for the cartilage at second-look arthroscopy.

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We divided 20 knees into two groups; one was composed of the knees in which cartilage status got worse in T 2 or MFC 5 (n ¼ 8) and the other was composed of the rest (n ¼ 12). We evaluated the contributing factors of cartilage degeneration in the T 2 and MFC 5

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3.4. Contributing factors of the specific subcompartments

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The score of each subcompartment is shown in Fig. 2. Cartilage injury of more than ICRS grade 1 was noted in 13 knees (65%) and 45 subcompartments (5.6%) at reconstruction and 18 knees (90%) and 134 subcompartments (16.8%) at second-look arthroscopy. Additionally, 111 (13.9%) of all 800 subcompartments became worse after reconstruction. Moreover, 669 (83.6%) of the remaining 689 subcompartments were unchanged and 20 (2.5%) improved. Cartilage injury significantly worsened in the MFC 5 and T 2 subcompartments, but no significant worsening was noted in other subcompartments. The worsened knee count in each subcompartment is described in the Fig. 3a. The improved knee count in each subcompartment is described in Fig. 3b.

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3.3. Cartilage grade of each subcompartment

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Fig. 1. Evaluation of cartilage lesions. a. Six compartments (P, patella; T, trochlea; MFC, medial femoral condyle; MTP, medial tibial plateau; LFC, lateral femoral condyle; LTP, lateral tibial plateau). b. Forty subcompartments. Each compartment was divided into subcompartments.

Please cite this article as: Hiranaka T et al., Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation, Journal of Orthopaedic Science, https://doi.org/10.1016/j.jos.2019.08.001

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T. Hiranaka et al. / Journal of Orthopaedic Science xxx (xxxx) xxx Table 2 Clinical and radiographic outcomes.

Lysholm score Tegner activity score IKDC score KOOS score Pain Symptoms Activities of daily living Sport and recreation function Knee-related quality of life Total Side-to-side difference of KT-2000 (mm) Pivot shift test (positive) Kellgren-Lawrence grade (0/1/2/3/4)

Preoperative

Second-look

P value

84.8 ± 14.3 4 (4e5) 63.4 ± 16.3

97.4 ± 6.4 6 (5e6) 89.0 ± 8.7

0.009* 0.017* 0.002*

82.7 ± 18.8 80.6 ± 17.5 92.4 ± 13.8 63.2 ± 25.5 58.1 ± 20.7 81.6 ± 16.1 3.6 ± 1.6 20 18/2/0/0/0

92.5 ± 8.4 89.6 ± 11.7 99.4 ± 0.7 89.6 ± 9.5 88.0 ± 12.8 94.4 ± 5.1 0.8 ± 1.6 0 18/2/0/0/0

0.058 0.167 0.100 0.005* 0.001* 0.021* <0.001* <0.001* 1.000

Data of Tegner score are presented as median (interquartile range). Data of Lysholm, International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), side-to- side difference of KT-2000 are presented as a mean ± standard deviation. *P < 0.05.

Table 3 Arthroscopic evaluation of the cartilage status in compartments. Reconstruction Patella Trochlea MFC MTP LFC LTP

0.4 0.4 0.8 0.4 0.1 0.9

± ± ± ± ± ±

Second-look

0.9 1.1 1.0 0.8 0.3 1.6

1.5 1.2 2.2 1.1 0.9 1.0

± ± ± ± ± ±

P value

1.9 1.4 1.7 1.6 1.3 1.0

0.019* 0.019* 0.005* 0.048* 0.022* 0.804

Medial femoral condyle, MFC. Medial tibial plateau, MTP. Lateral femoral condyle, LFC. Lateral tibial plateau, LTP. The condition of the articular cartilage was graded according to the International Cartilage Repair Society (ICRS) articular cartilage injury classification. Data are displayed as a mean ± standard deviation. *P < 0.05.

subcompartments, which included gender, age, height, weight, body mass index, time from injury to the reconstruction, medial and lateral compartment bone bruise in preoperative MRI, postoperative side-to-side difference of KT-2000, and no cartilage

a

4. Discussion The most important finding of the present study was that good cartilage conditions were restored in most subcompartments at second-look arthroscopy. Furthermore, a significant worsening was observed in the MFC 5 and T 2 subcompartments and in all the compartments except the LTP, despite good knee stability and clinical outcomes at second-look arthroscopy. There have been some reports about the location of posttraumatic osteoarthritis after ACLR. Some radiographic reports have shown that posttraumatic osteoarthritis occurred at the PF and medial TF joints with long-term follow-up [19,20]. Standard MRI techniques have proven more useful and more precise than 0.3 (4)

b

0.1 (2)

0.1 (1)

injury at reconstruction. No other contributing factor were identified between the two groups (p value ¼ 1, 0.245, 0.451, 0.426, 0.543, 0.761, 0.761, 0.443, and 0.085).

0.3 (5)

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0.1 (2)

0.5 0.4

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0.8* (8)

0.2 0.2 0.2 0.1 (3) (3 3) (2) (2)

0.7 0.3 0.4 0 .1 0 0.1 (1) (6) (6)

0.1 (2)

0.1 (2) 0.4 (6) 0.1 (1)

0.3 (5)

0.4 0 0.7* 0.7 (7) (13) (12) 0.1 (1)

0.1 (2) 0.1 (1) 0.1 (1)

0.8 0.1 (2)

0.7 0.6

0.3 0.3 (6) (5)

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0.1 0.3 (1) (4) 0.1 (1)

0.1 (1) 0.3 0.4 (5) (7) 0.1 (1)

0.2 0.1 (2)

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0.1 (2) 0.3 0.5 0.1 (5) (10) (2) 0.1 (2)

0.2 (3) 0.5 0.4 (8) (7)

0.2 0.1 (1)

0.1 0

Fig. 2. Subcompartment scores. a. The sum of subcompartment scores at reconstruction. b. The sum of subcompartment scores at second-look arthroscopy. * shows the subcompartments where significant worsening was found. The number of cases with a cartilage lesion at each surgery is shown below the average values enclosed in parentheses.

Please cite this article as: Hiranaka T et al., Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation, Journal of Orthopaedic Science, https://doi.org/10.1016/j.jos.2019.08.001

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Fig. 3. a. The knee count for worsening grade of cartilage injury in each subcompartment. b. The knee count for improving grade of cartilage injury in each subcompartment.

radiographic techniques in detecting early degenerative cartilage change associated with cartilage injury. Su et al. quantified longitudinal changes in cartilage morphology and matrix in ACL-injured knees 2 years after ACLR using quantitative MRI. Their findings showed that significant progression of early degenerative change had occurred at the central aspect of MFC [21]. Lee et al. evaluated the changes in the site-specific cartilage status after a doublebundle ACLR using preoperative and follow-up MRI. They reported that the medial facet of the patella, anterior region of the lateral femur, and central region of the medial femur showed significantly more cartilage loss than the posterior and anterior regions of the medial tibia and the central and anterior regions of the lateral tibia 26 months after double-bundle ACLR [5]. These reports were consistent with our outcome which showed the significant increase of cartilage injury at MFC 5 subcompartment after ACLR. However, there are few reports about the progression of degenerative change after ACLR using arthroscopy. Asano et al. evaluated the articular cartilage lesion at reconstruction and at second-look arthroscopy to clarify the change in articular cartilage. A significant worsening was observed in all articular compartments except in LFC [6]. Previous reports have not discussed the reason for degenerative changes in specific subcompartments in detail. Previous kinematic study of ACL-reconstructed knees has reported substantially altered TF motion, resulting in a shift of cartilage compartments and in their contact with each other, and in the progression of early osteoarthritis [22]. Carpenter et al. described that, when knees were fully extended, the tibia in ACLreconstructed knees were externally rotated by 3.6 ± 4.2 compared with the contralateral knees. They also showed that knee kinematic change was observed in the medial compartment [23]. Hoshino et al. reported that the mean joint sliding distance in the medial compartment was larger in reconstructed knees than in contralateral knees for anatomical double-bundle reconstruction [24]. In these reports, knee kinematic change was observed in the medial compartment and the tibia was externally rotated when the knees were fully extended, compared with the contralateral knee.

This kinematic change might contribute to the progression of degenerative change in the medial compartment. There are few reports on the kinematics of the PF joint after ACLR. Gong et al. reported that double-bundle ACLR resulted in less cartilage damage at the femoral trochlea on short-term follow-up [25]. Tajima et al. reported that a normal PF contact area and pressure were more closely restored with anatomic double-bundle ACLR than with non-anatomic single-bundle ACLR [26]. Additionally, Van de Velde et al. showed that abnormal patellar rotation, tilt, and lateral shift persisted after single-bundle ACLR [27]. On the other hand, Wang et al. showed that less severe patellar chondral lesions after double-bundle ACLR were associated with 80% recovery of quadriceps muscle strength [28]. In this study, although we used the double-bundle ACLR technique, osteoarthritic change in the PF joint was observed in the short term. The reason for this appears to be the temporary increase in mechanical stress to the PF joint because of the anterior instability being controlled drastically by the ACLR. Further consideration of the postoperative rehabilitation protocol or kinematic change after reconstruction might be needed for the PF joint cartilage preservation. Some factors as those mentioned above concerning kinematic change after ACLR might be related with our present results, which demonstrated cartilage degeneration at the MFC 5 and T 2 subcompartments. These worsening early osteoarthritis features on arthroscopy may reflect a progressive disease pathway that identifies those likely to experience future radiographic osteoarthritis and symptoms. Identifying patients with progressive early osteoarthritis features after natural biological graft healing and functional rehabilitation, but before established joint disease, may present opportunities to develop secondary prevention strategies. It is not clear why significant worsening was noted at the MFC 5 and T 2 subcompartments among all the subcompartments and at all the compartments except the LTP. We couldn't identify any contributing factors for cartilage degeneration in specific subcompartments. We think that the progression of cartilage damage couldn't be stopped completely after ACLR and the damage might

Please cite this article as: Hiranaka T et al., Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation, Journal of Orthopaedic Science, https://doi.org/10.1016/j.jos.2019.08.001

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become obvious about one year after reconstruction. Further investigations seem necessary to identify the exact cause of the posttraumatic osteoarthritis after double-bundle reconstruction. Our study has several limitations that must be considered. First, a comparatively small sample size was investigated. Thus, further studies with more patients are needed. Second, the follow-up of this study was short because most patients returned for implant removal about 15 months after surgery. Thus, cartilage degeneration of the knee joint in the longer term is unclear. Third, the kinematic change in the knee joint was not examined in this study, which is thought to be the cause of the posttraumatic osteoarthritis after ACLR. Future investigation about postoperative kinematic change seems necessary. 5. Conclusion We compared site-specific cartilage injury after double-bundle ACLR at reconstruction and at second-look arthroscopy. Good cartilage conditions were restored in most subcompartments at second-look arthroscopy. Furthermore, significant worsening of the cartilage was observed at the central part of MFC and trochlea among all subcompartments and in all the compartments except the LTP, despite the achievement of good knee stability and clinical outcomes at second-look arthroscopy. Attention is required in the progression of osteoarthritis and the appearance of knee symptoms in those who undergo ACLR. Conflicts of interest SM declares that his salary is supported by Teijin Nakashima Medical Co. Ltd. EN declares that their salaries are supported by Okayama Saidaiji Hospital. The other authors report no conflicts of interest. Acknowledgements We are grateful to Ms. Ami Maehara for preparing schematic illustrations. Further, we would like to thank Editage (http://www. editage.jp) for English language editing. References [1] Ferretti A, Conteduca F, De Carli A, Fontana M, Mariani PP. Osteoarthritis of the knee after ACL reconstruction. Int Orthop 1991 Dec;15(4):367e71. [2] Lohmander LS, Englund PM, Dahl LL, Roos EM. The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis. Am J Sports Med 2007 Oct;35(10):1756e69. [3] Pollard TC, Gwilym SE, Carr AJ. The assessment of early osteoarthritis. J Bone Joint Surg Br 2008 Apr;90(4):411e21. [4] Culvenor AG, Collins NJ, Guermazi A, Cook JL, Vicenzino B, Khan KM, Beck N, van Leeuwen J, Crossley KM. Early knee osteoarthritis is evident one year following anterior cruciate ligament reconstruction: a magnetic resonance imaging evaluation. Arthritis Rheum 2015 Apr;67(4):946e55. [5] Lee YS, Jeong YM, Sim JA, Kwak JH, Kim KH, Nam SW, Lee BK. Specific compartmental analysis of cartilage status in double-bundle ACL reconstruction patients: a comparative study using pre- and postoperative MR images. Knee Surg Sport Traumatol Arthrosc 2013 Mar;21(3):702e7. [6] Asano H, Muneta T, Ikeda H, Yagishita K, Kurihara Y, Sekiya I. Arthroscopic evaluation of the articular cartilage after anterior cruciate ligament reconstruction: a short-term prospective study of 105 patients. Arthroscopy 2004 May;20(5):474e81. [7] Fujii M, Furumatsu T, Miyazawa S, Tanaka T, Inoue H, Kodama Y, Masuda K, Seno N, Ozaki T. Features of human autologous hamstring graft elongation after pre-tensioning in anterior cruciate ligament reconstruction. Int Orthop 2016 Dec;40(12):2553e8.

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Please cite this article as: Hiranaka T et al., Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation, Journal of Orthopaedic Science, https://doi.org/10.1016/j.jos.2019.08.001