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The characteristics of inverted lateral discoid meniscus tears : A case series
Abstracts / Asia-Pacific Journal of Sports Medicine, Arthroscopy, Rehabilitation and Technology 9 (2017) 59e124
effective anchorage. However, proximal migration still occurred in some cases. Intramedullary (IM) rodding has been the mainstay of long-bone stabilization in osteogenesis imperfecta, while plates create a stress raiser effect and should not be used. However, in some cases, intramedullary rodding cannot provide adequate fixation because of a lack of rotational control and thin diameter of long bones. In Ho Choi et al demonstrated unicortical locking plate fixation effectively supplements intramedullary rod fixation in selected cases of osteogenesis imperfecta. In our case, it might be another way to solve to genu valgum rather than simply using FD nail. However, the cost of locking plate is not including in our national health insurance, so we finally choose Kirschner pins for fixation. Conclusion: Recent surgical advances have allowed improved safety, function and comfort in treating patient with osteogenesis imperfecta. The selection of surgical techniques is dependent on surgeon experience and patient’s situation. Though not an optimal device, Fassier-Duval nail could be used as an IM nail for corrective osteotomy at the distal femur in adult OI patients with a smaller femoral canal. Accurate entry point is very important at retrograde rodding. After removal of the previous IM nail, a stop screw or pin may be necessary to prevent rod dropping when using FD nail as a fixation device for the revision surgery. Keywords: Corrective osteotomy, Fassier Duval, Retrograde, Genu valgum, Osteogenesis imperfecta
Knee - Meniscus EP-020 THE CHARACTERISTICS OF INVERTED LATERAL DISCOID MENISCUS TEARS : A CASE SERIES Kengo Shimozaki 1, Junsuke Nakase 1, Yasushi Takata 1, Katsuhiko Kitaoka 2, Hiroyuki Tsuchiya 1. 1 Department of Orthopedic Surgery, Kanazawa University Hospital, Japan; 2 Department of Orthopedic Surgery, Kijima Hospital, Japan Introduction: Discoid lateral meniscus lesions are relatively rare, and their origin is uncertain. Previous reports indicate that the central portion of a discoid meniscus is subjected to shear stress and is easily damaged due to repeated minor trauma. Tear patterns in a discoid meniscus have been categorized as complex or vertical, among others. However, an inverted discoid meniscus tear has not been described in detail. In this series, we present a rare type of discoid meniscus tear in which a torn portion of the central discoid body is inverted beneath the intact posterior peripheral horn of the lateral meniscus. The purpose of this case series is to describe the characteristic physical and magnetic resonance imaging (MRI) findings of inverted lateral discoid meniscus tears. Materials and Methods: Between 2014 and 2016, 12 patients (9 males and 3 females) underwent arthroscopic partial meniscectomy for an inverted lateral discoid meniscus tear. The average patient age at the time of surgery was 19.6±5.7 years (range 15 to 33). Eleven were injured playing sports, and one was injured during routine activity. The mean duration between trauma and surgery was 64.1±72.4 days (range 3 to 240). The definition of an inverted lateral discoid meniscus tear is the arthroscopic finding of a torn portion of the central discoid body inverted beneath the intact posterior peripheral horn of the lateral meniscus. We assessed preoperative knee range of motion (ROM), swelling, knee pain and location, the McMurray test, knee locking or catching, and MRI findings to determine which of these can support the diagnosis of an inverted lateral discoid meniscus tear. On MRI, diagnostic criteria for a discoid meniscus were determined using meniscal width, ratio of the meniscus to the tibia, percent coverage of the meniscus, and continuity of the anterior and posterior horns. The criteria for an inverted tear included duplication or enlargement of the posterior horn and blunting of the inner rim in the sagittal plane. Results: The preoperative, average knee extension range was -2.5±5.0 (-15 to 0) degrees, and the average knee flexion range of 128±23.3 (80 to 150) degrees included 9 non-limitation cases. Eleven cases had swelling and pain around the lateral joint space on motion. The McMurray test was positive in 4 cases, with locking in only one. Although a lateral meniscus tear was diagnosed in all cases, only 3 had
89
been diagnosed with a lateral discoid meniscus tear. Nine cases had a suspected inverted tear, with a duplicated or enlarged posterior horn and blunting of the inner rim in the sagittal plane on MRI. Two of 3 cases had been diagnosed with a lateral discoid meniscus tear, but did not have a suspected inverted tear. Discussion: Symptomatic discoid meniscus patients with or without tears, especially when young, generally have no traumatic history, and often have mechanical findings. In this series, 11case had traumatic history when they played sports, and 9 cases did not have limitation of ROM, 4 had positive findings on a McMurray test, and only one had locking, which is a relatively infrequent finding, compared with that observed in normal discoid or non-discoid meniscus tears. In addition, the mean duration between trauma and surgery of inverted discoid meniscus tears was longer than normal discoid or non-discoid meniscus tears. These may be due to the characteristics of inverted discoid meniscus tears. A stable position may develop because the bulk of the torn portion favors a resting position below the peripheral rim. The difficulty in diagnosing an inverted lateral discoid meniscus tear by MRI is predictable. Because the torn portion of the central discoid body is inverted beneath the intact posterior peripheral horn, a “C” shape resembling that of a normal meniscus is observed. Few features indicate a discoid meniscus. Nine cases had a duplicated or enlarged posterior horn and blunting of the inner rim in the sagittal plane on MRI, making it useful for diagnosing an inverted tear. Two cases did not have characteristic MRI findings for an inverted tear. These were diagnosed as a lateral discoid meniscus on MRI, and had a smaller amount of meniscus inversion compared with other cases on arthroscopy. This partly explains why we could not diagnose an inverted tear in these cases. In cases with suspected meniscus injury and an inverted tear on MRI, despite the lack of specific MRI findings for a lateral discoid meniscus, we should consider a diagnosis of an inverted lateral discoid meniscus tear and make the determination based on a comprehensive examination and physical findings. On arthroscopy, all cases with an inverted lateral discoid meniscus tear showed a central portion tear of the lateral discoid meniscus moving under the intact posterior peripheral rim. In all cases, it was necessary to expose the inverted central portion with probing. A recently recommended treatment plan for a discoid meniscus tear is arthroscopic meniscal reshaping and meniscoplasty. In many cases, meniscus repair or peripheral reattachment can be performed if there is associated instability, but tears of the anterior or posterior peripheral meniscus rim were not seen, and there was no instability. Thus, there were no cases that underwent meniscus repair, and only arthroscopic partial meniscectomy was performed. Conclusions: Inverted lateral discoid meniscus tears infrequently have characteristic physical and MRI findings, compared with the findings in common lateral discoid meniscus tears. Clues to the diagnosis of an inverted lateral discoid meniscus tear are an inverted meniscus and blunting of the inner rim on MRI sagittal plane views. Keywords: lateral discoid meniscus, inverted tear, MRI, arthroscopy, characteristics
Knee - Meniscus EP-023 COMPARISON OF ARTHROSCOPIC PARTIAL MENISCECTOMY WITH PHYSICAL THERAPY ALONE CO EXISTING MENISCAL TEAR AND KNEE OSTEOARTHRITIS Atul Mahajan, Atul Mahajan, Dr Mukesh Kalra. Department of Orthopedics, Lhmc, India Objective: In patients with a meniscal tear and mild-tomoderatev osteoarthritis, we analysed whether arthroscopic partial meniscectomy improve physical and functional outcomes more than physical therapy does. Design: Randomized, un blinded, controlled trial with 12 months of follow-up.
effective anchorage. However, proximal migration still occurred in some cases. Intramedullary (IM) rodding has been the mainstay of long-bone stabilization in osteogenesis imperfecta, while plates create a stress raiser effect and should not be used. However, in some cases, intramedullary rodding cannot provide adequate fixation because of a lack of rotational control and thin diameter of long bones. In Ho Choi et al demonstrated unicortical locking plate fixation effectively supplements intramedullary rod fixation in selected cases of osteogenesis imperfecta. In our case, it might be another way to solve to genu valgum rather than simply using FD nail. However, the cost of locking plate is not including in our national health insurance, so we finally choose Kirschner pins for fixation. Conclusion: Recent surgical advances have allowed improved safety, function and comfort in treating patient with osteogenesis imperfecta. The selection of surgical techniques is dependent on surgeon experience and patient’s situation. Though not an optimal device, Fassier-Duval nail could be used as an IM nail for corrective osteotomy at the distal femur in adult OI patients with a smaller femoral canal. Accurate entry point is very important at retrograde rodding. After removal of the previous IM nail, a stop screw or pin may be necessary to prevent rod dropping when using FD nail as a fixation device for the revision surgery. Keywords: Corrective osteotomy, Fassier Duval, Retrograde, Genu valgum, Osteogenesis imperfecta
Knee - Meniscus EP-020 THE CHARACTERISTICS OF INVERTED LATERAL DISCOID MENISCUS TEARS : A CASE SERIES Kengo Shimozaki 1, Junsuke Nakase 1, Yasushi Takata 1, Katsuhiko Kitaoka 2, Hiroyuki Tsuchiya 1. 1 Department of Orthopedic Surgery, Kanazawa University Hospital, Japan; 2 Department of Orthopedic Surgery, Kijima Hospital, Japan Introduction: Discoid lateral meniscus lesions are relatively rare, and their origin is uncertain. Previous reports indicate that the central portion of a discoid meniscus is subjected to shear stress and is easily damaged due to repeated minor trauma. Tear patterns in a discoid meniscus have been categorized as complex or vertical, among others. However, an inverted discoid meniscus tear has not been described in detail. In this series, we present a rare type of discoid meniscus tear in which a torn portion of the central discoid body is inverted beneath the intact posterior peripheral horn of the lateral meniscus. The purpose of this case series is to describe the characteristic physical and magnetic resonance imaging (MRI) findings of inverted lateral discoid meniscus tears. Materials and Methods: Between 2014 and 2016, 12 patients (9 males and 3 females) underwent arthroscopic partial meniscectomy for an inverted lateral discoid meniscus tear. The average patient age at the time of surgery was 19.6±5.7 years (range 15 to 33). Eleven were injured playing sports, and one was injured during routine activity. The mean duration between trauma and surgery was 64.1±72.4 days (range 3 to 240). The definition of an inverted lateral discoid meniscus tear is the arthroscopic finding of a torn portion of the central discoid body inverted beneath the intact posterior peripheral horn of the lateral meniscus. We assessed preoperative knee range of motion (ROM), swelling, knee pain and location, the McMurray test, knee locking or catching, and MRI findings to determine which of these can support the diagnosis of an inverted lateral discoid meniscus tear. On MRI, diagnostic criteria for a discoid meniscus were determined using meniscal width, ratio of the meniscus to the tibia, percent coverage of the meniscus, and continuity of the anterior and posterior horns. The criteria for an inverted tear included duplication or enlargement of the posterior horn and blunting of the inner rim in the sagittal plane. Results: The preoperative, average knee extension range was -2.5±5.0 (-15 to 0) degrees, and the average knee flexion range of 128±23.3 (80 to 150) degrees included 9 non-limitation cases. Eleven cases had swelling and pain around the lateral joint space on motion. The McMurray test was positive in 4 cases, with locking in only one. Although a lateral meniscus tear was diagnosed in all cases, only 3 had
89
been diagnosed with a lateral discoid meniscus tear. Nine cases had a suspected inverted tear, with a duplicated or enlarged posterior horn and blunting of the inner rim in the sagittal plane on MRI. Two of 3 cases had been diagnosed with a lateral discoid meniscus tear, but did not have a suspected inverted tear. Discussion: Symptomatic discoid meniscus patients with or without tears, especially when young, generally have no traumatic history, and often have mechanical findings. In this series, 11case had traumatic history when they played sports, and 9 cases did not have limitation of ROM, 4 had positive findings on a McMurray test, and only one had locking, which is a relatively infrequent finding, compared with that observed in normal discoid or non-discoid meniscus tears. In addition, the mean duration between trauma and surgery of inverted discoid meniscus tears was longer than normal discoid or non-discoid meniscus tears. These may be due to the characteristics of inverted discoid meniscus tears. A stable position may develop because the bulk of the torn portion favors a resting position below the peripheral rim. The difficulty in diagnosing an inverted lateral discoid meniscus tear by MRI is predictable. Because the torn portion of the central discoid body is inverted beneath the intact posterior peripheral horn, a “C” shape resembling that of a normal meniscus is observed. Few features indicate a discoid meniscus. Nine cases had a duplicated or enlarged posterior horn and blunting of the inner rim in the sagittal plane on MRI, making it useful for diagnosing an inverted tear. Two cases did not have characteristic MRI findings for an inverted tear. These were diagnosed as a lateral discoid meniscus on MRI, and had a smaller amount of meniscus inversion compared with other cases on arthroscopy. This partly explains why we could not diagnose an inverted tear in these cases. In cases with suspected meniscus injury and an inverted tear on MRI, despite the lack of specific MRI findings for a lateral discoid meniscus, we should consider a diagnosis of an inverted lateral discoid meniscus tear and make the determination based on a comprehensive examination and physical findings. On arthroscopy, all cases with an inverted lateral discoid meniscus tear showed a central portion tear of the lateral discoid meniscus moving under the intact posterior peripheral rim. In all cases, it was necessary to expose the inverted central portion with probing. A recently recommended treatment plan for a discoid meniscus tear is arthroscopic meniscal reshaping and meniscoplasty. In many cases, meniscus repair or peripheral reattachment can be performed if there is associated instability, but tears of the anterior or posterior peripheral meniscus rim were not seen, and there was no instability. Thus, there were no cases that underwent meniscus repair, and only arthroscopic partial meniscectomy was performed. Conclusions: Inverted lateral discoid meniscus tears infrequently have characteristic physical and MRI findings, compared with the findings in common lateral discoid meniscus tears. Clues to the diagnosis of an inverted lateral discoid meniscus tear are an inverted meniscus and blunting of the inner rim on MRI sagittal plane views. Keywords: lateral discoid meniscus, inverted tear, MRI, arthroscopy, characteristics
Knee - Meniscus EP-023 COMPARISON OF ARTHROSCOPIC PARTIAL MENISCECTOMY WITH PHYSICAL THERAPY ALONE CO EXISTING MENISCAL TEAR AND KNEE OSTEOARTHRITIS Atul Mahajan, Atul Mahajan, Dr Mukesh Kalra. Department of Orthopedics, Lhmc, India Objective: In patients with a meniscal tear and mild-tomoderatev osteoarthritis, we analysed whether arthroscopic partial meniscectomy improve physical and functional outcomes more than physical therapy does. Design: Randomized, un blinded, controlled trial with 12 months of follow-up.