Jin Wan Kim, Youn Soo Hwang, Kyu Pill Moon, Kyung Taek Kim, Joon Yeon Song

Transcription

1 Case Report pissn X eissn rthroscopic fixation with a cannulated screw for avulsion fractures of the tibial spine in children: a report of two cases Jin Wan Kim, Youn Soo Hwang, Kyu Pill Moon, Kyung Taek Kim, Joon Yeon Song Department of Orthopedic Surgery, Dong-Eui Medical Center, usan, Korea n anterior cruciate ligament (CL) avulsion fracture of the tibial spine is uncommon and occurs mostly in pediatric patients. Pediatric CL avulsion fractures can be treated surgically through arthroscopic surgery or open surgery. Recently, arthroscopic surgery has been performed more often than open surgery because the former has been associated with a lower incidence of postoperative complications. Screws, K-wires, and suture anchors have been used as fixative devices during an arthroscopic fixation. Cannulated screw fixation is a simple method for a solid fixation, but it has the risk of causing damage to the growth plate. We report favorable results using a cannulated screw for two cases of pediatric CL avulsion fractures. Keywords: Tibial spine; vulsion fracture; Cannulated screw; Child INTRODUCTION The anterior cruciate ligament (CL) avulsion fracture of the tibial spine was first described in 1875 by Poncet [1]. CL avulsion fractures at the tibial spine occur through either severe torsion-induced injury or valgus or varus injury but rarely through direct injury. vulsion fractures are caused because the CL attachment at the proximal tibial epiphyseal plate is anatomically weak rather than because the CL itself receives traction force due to hyperextension of the knee. In particular, it frequently occurs in children and adolescents aged between 8 and 12 years [2 4]. Twisting injuries and bicycle falls are known to be the most common etiological causes of an CL tibial spine avulsion fracture [5,6], but it was recently reported to have occurred in adults as a result of traffic accidents and sports injuries [7]. The treatment of CL avulsion fractures of the tibial spine can be divided into conservative treatment and surgical treatment. The surgical treatment includes fixation through arthroscopic surgery or open surgery. Various methods of arthroscopic fixation have been studied such as fixation through K-wires, pull-out suture, suture anchors, or cannulated screws with wires or alone [8]. The advantages and disadvantages of each method have been reported, yet the gold standard of surgical technique has not been established. In this study, we report, along with a review of the current literature, of satisfactory outcomes after two patients with CL avulsion fractures of the tibial spine underwent an arthroscopic fixation using cannulated screws. CSE REPORTS Case 1 n eight-year-old girl was admitted to hospital because of instability and pain in her right knee after she sustained a twisting injury while running. Through physical examination, we found that the patient presented with tenderness and swelling in the right knee. lso, the patient was positive for the anterior drawer test and for the lachman test (++/++) and had a Lysholm knee score of 65. Through preoperative simple radiography (Fig. 1) and magnetic resonance imaging (Fig. 1), we found a rthroscopy and Orthopedic Sports Medicine OSM Received November 3, 2015; Revised December 2, 2015; ccepted December 2, 2015 Correspondence to: Youn Soo Hwang, Department of Orthopedic Surgery, Dong-Eui Medical Center, 62 Yangjeong-ro, usanjingu, usan 47227, Korea. Tel: , Fax: , hangulum@hanmail.net Copyright 2016 Korean rthroscopy Society and Korean Orthopedic Society for Sports Medicine. ll rights reserved. CC This is an open-access article distributed under the terms of the Creative Commons ttribution Non-Commercial License ( by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. rthrosc Orthop Sports Med 2016;3(1):

2 Fig. 1. () preoperative plain radiograph of an eight-year-old girl with type III avulsion fracture of the tibial spine (arrows). () preoperative magnetic resonance image of an avulsion fracture of the anterior cruciate ligament (arrow). C Fig. 2. rthroscopic findings of an avulsion fracture of the anterior cruciate ligament and a hematoma (), an incomplete tear of the lateral meniscal posterior horn (), and an accurate fixation with a cannulated screw (C). Meyers-McKeever type III avulsion facture in which the tibial intercondylar eminence was completely separated from the tibial attachment site. The size of the bone fragment was nearly 1.6 cm in length and 1.1 cm in width. The surgery was performed around a week of the injury. Through arthroscopic examination, we found that the 50 Fig. 3. rthroscopic findings at the 6th postoperative week show the healed avulsed bony fragment () and the completely healed lateral meniscus (). avulsion fracture fragment was completely separated from the CL attachment site (Fig. 2) and that the posterior horn of the lateral meniscus was torn incompletely and longitudinally (Fig. 2). We obtained an anatomical reduction using an arthroscopic probe or a microfracture pick with the knee in 30o to 90o of flexion. Under C-arm

3 fluoroscopy, a guide pin was inserted through the superior medial portal, and the fracture fragment was fixed by inserting a 4.0 mm cannulated screw following the guide pin (Fig. 2C). When inserting the guide pin, we took care not to penetrate the growth plate and to damage the medial femoral condyle by the screw thread. The incomplete tear of the posterior horn of the lateral meniscus was conservatively treated. s part of the postoperative rehabilitation program, the patient was allowed partial weight-bearing and was applied a cylinder splint for 3 weeks, after which range of motion exercises of 0o to 90o and full weight-bearing were allowed. y the 5th postoperative week, we found that the patient was clear of pain and discomfort in the knee. We found the following postoperative findings: a successful bony union through plain radiography; a full range of motions; normal lachman and anterior drawer test results; and a Lysholm knee score of 82. secondary arthroscopic examination was performed six weeks after the surgery during which we found that the avulsed bony fragment was completely healed, so the cannulated screw was removed (Fig. 3). Despite the fact that we did not attempt any reparative measures, we observed that the lateral meniscal tear was spontaneously resolved (Fig. 3). t a 1-year follow-up, the patient was able to exercise a complete range of motions without gait disturbance and showed no symptoms of instability. Case 2 nine-year-old boy was admitted to hospital for pain and swelling in his left knee as a result of a direct injury while running. Through physical examination of the patient, we found that he had tenderness and swelling in his left knee, positive results for the anterior drawer test and for the lachman test (++/++), and a Lysholm knee score of 54. Through preoperative simple radiography (Fig. 4) C Fig. 4. () Preoperative plain radiographs of a nine-year-old boy with type III avulsion fracture of the tibial spine (arrows). () preoperative magnetic resonance image of an avulsion fracture of the anterior cruciate ligament (arrow). (C) rthroscopic findings of an avulsion fracture of the anterior cruciate ligament. Fig. 5. () simple radiograph at the five month follow-up shows accurate reduction of the avulsion fracture and a successful bony union. () rthroscopic finding at the 6th postoperative month shows the healed avulsed bony fragment. 51

4 and magnetic resonance imaging (Fig. 4), we observed a Meyers-McKeever type III avulsion fracture. The dimension of the bone fragment was nearly 1.5 cm in length and 1.2 cm in width. The surgery was performed 2 days of the injury. rthroscopically, we found that the avulsion fracture fragment was completely separated from the CL attachment site (Fig. 4C). The fracture fragment was fixed using a 4.0 mm cannulated screw, and care was taken to avoid the physis of the proximal tibia. The postoperative rehabilitation comprised a cylinder splint fixation and partial weight-bearing for four weeks and a range of motion of 0 o to 90 o and full weight-bearing thereafter. t the 5-month follow-up, we found that the patient showed an accurate reduction of the avulsion fracture and a successful bony union using simple radiography (Fig. 5) and a Lysholm knee score of 84. t the secondary arthroscopic examination which we performed six months after surgery, we found that the avulsed bony fragment was completely healed (Fig. 5), so the cannulated screw was removed. No abnormal findings such as knee instability or inhibition in motion were observed at the 8-month follow-up. DISCUSSION Pediatric CL avulsion fracture has been reported to frequently occur in individuals aged between 8 and 12 years. Isolated CL avulsion fractures accompanied by medial collateral ligament and meniscal injuries usually occur as a result of a hyperextension injury. Of the accompanying meniscal injuries, lateral meniscal injuries in the marginal area have been often reported [4,9]. Kendall et al. [5] reported that tibial spine fractures are accompanied by a concomitant injury in 68% of cases, in both adults and children. Clanton et al. [10] reported that the accompanying injury occurs more often in the meniscus, especially in the lateral meniscus, than in other areas. Likewise, in the case described in our study, we found a concomitant, incomplete longitudinal tear in the posterior horn of the lateral meniscus, which resolved with conservative treatment. It is known that for the treatment of types I and II avulsion fractures, which are classified according to the Meyers and Mckeever s classification, a conservative treatment is sufficient; whereas, for types III and IV, a surgical treatment is required. ut when a type II fracture with increased displacement switches to a type III fracture, it has been found that reduction of the fragment becomes difficult even with surgical treatment. Further, in some cases where a bony union is achieved through conservative treatment, chronic instability of the knee may still persist. For these reasons, sometimes an early surgical treatment is critical for a functional recovery of the knee [7,9]. In the past, open surgery was the method frequently performed for CL avulsion fractures, but arthroscopic surgery has now replaced it because of its association with a swift recovery. Not only this, arthroscopy is an invaluable tool in identifying and treating accompanying intra-articular lesions. Recently, various fixation devices have been utilized during arthroscopic surgery such as K-wires, pull-out suture, suture anchors, and cannulated screws. K-wires can be used to fix a fracture with relative ease, but its disadvantages are that the strength of fixation is relatively weak even when the fragment is large enough and that they are difficult to use for a comminuted fracture. On the other hand, pull-out suture or a suture anchor can be used to tightly fix small bone fragments or a comminuted fracture, but it requires a relatively complex surgical procedure. Cannulated screw fixation has the advantages of expediting motion during rehabilitation, having an easy surgical technique, and providing a tight fixation. Delcogliano et al. [11] reported that when the size of an avulsion is large enough, a screw fixation is recommended because it provides the most stable form of fixation. large enough fragment for screw insertion is deemed as a fragment of > 15 mm [12], which can be a threshold used to judge whether an individual with an CL avulsion fracture should be indicated for screw fixation or not. However, when a fracture fragment is small or a comminuted, cannulated screw fixation cannot be used because the articular cartilage can be damaged by the screw thread during its insertion. In any case, care must be taken to prevent articular damage resulting from the procedure. nother disadvantage of screw fixation may be the need for a second surgical procedure to remove the hardware, but this can be used for the benefit of the patient by taking it as an opportunity to evaluate bone healing and accompanying injuries. Postoperative complications such as anterior instability of the knee and restricted extension after surgical reduction have often been reported. axter and Wiley [1] reported from their study on 45 cases of CL avulsion fractures of more than three years of follow-up that, though no patient complained of subjective instability of the knee, anterior laxity was shown in 51% of the patients after an anterior drawer test. They mentioned that ante- 52

5 rior laxity or a certain degree of restriction in extension was inevitable because the thickening of the tibial spine which disturbs the normal function of the CL and is accompanied by intraparenchymal damage of the CL. Grönkvist et al. [2] reported that loosening of the CL after union occurred in 33% of patients under 10 years old and in 75% of patients over 10 years old. lso, they reported that some compensation can be expected in children regarding the compromised CL, but as the age increases, the degree of compensation declines. So they recommended that the older the patient, the greater the extent the CL tension that should be recovered during the surgery. In the two reported cases in our study, anterior laxity and restriction in extension were not observed. In this study, we found favorable results at short-term follow-up using cannulated screws for the arthroscopic fixation of CL avulsion fractures of the tibial spine. CONFLICT OF INTEREST No potential conflict of interest relevant to this article was reported. REFERENCES 1. axter MP, Wiley JJ. Fractures of the tibial spine in children. n evaluation of knee stability. J one Joint Surg r 1988;70: Grönkvist H, Hirsch G, Johansson L. Fracture of the anterior tibial spine in children. J Pediatr Orthop 1984;4: Iobst C, Stanitski CL. cute knee injuries. Clin Sports Med 2000;19: Song EK, Seol JY, Choi J. The surgical treatment of chronic avulsion fracture of the anterior cruciate ligament. J Korean rthroscopy Soc 2002:6; Kendall NS, Hsu SY, Chan KM. Fracture of the tibial spine in adults and children. review of 31 cases. J one Joint Surg r 1992;74: Molander ML, Wallin G, Wikstad I. Fracture of the intercondylar eminence of the tibia: a review of 35 patients. J one Joint Surg r 1981;63-: Meyers MH, McKeever FM. Fracture of the intercondylar eminence of the tibia. J one Joint Surg m 1970;52: hn JH, Yoo JC. Clinical outcome of arthroscopic reduction and suture for displaced acute and chronic tibial spine fractures. Knee Surg Sports Traumatol rthrosc 2005;13: Seon JK, Park SJ, Lee K, et al. clinical comparison of screw and suture fixation of anterior cruciate ligament tibial avulsion fractures. m J Sports Med 2009;37: Clanton TO, DeLee JC, Sanders, Neidre. Knee ligament injuries in children. J one Joint Surg m 1979;61: Delcogliano, Chiossi S, Caporaso, Menghi, Rinonapoli G. Tibial intercondylar eminence fractures in adults: arthroscopic treatment. Knee Surg Sports Traumatol rthrosc 2003;11: ndo T, Nishihara K. rthroscopic internal fixation of fractures of the intercondylar eminence of the tibia. rthroscopy 1996;12: