Auris Nasus Larynx 42 (2015) 241–244
Contents lists available at ScienceDirect
Auris Nasus Larynx journal homepage: www.elsevier.com/locate/anl
Retrieval of ruptured medial rectus muscle with an endoscopic endonasal orbital approach. A case report and indication for surgical technique Kosuke Akiyama a,*, Masayuki Karaki b, Hiroshi Hoshikawaa a, Nozomu Mori a a b
Department of Otolaryngology, Faculty of Medicine, Kagawa University, Kita-gun, Miki-cho, Ikenobe 1750-1, Kagawa 761-0793, Japan Tanaka ENT Clinic, Tyuou-ku, Shinshigai 7-17, Kumamoto 860-0803, Japan
A R T I C L E I N F O
A B S T R A C T
Article history: Received 19 June 2014 Accepted 24 October 2014 Available online 16 November 2014
Introduction: Rupture of the extraocular muscle is extremely rare, and a traumatic event is especially uncommon. Although retrieval of an injured MRM is usually performed by an anterior approach by an ophthalmologist, missing muscles in the orbital retrobulbar space are sometimes difficult to identify. This is the first report to demonstrate direct muscle to muscle anastomosis by an endoscopic endonasal orbital approach by a single otolaryngologist. Case report: A 67-year-old man presented with left medial rectus muscle (MRM) rupture due to a traffic accident 4 months after injury. The MRM was completely ruptured, and the muscle was repaired by an endoscopic endonasal orbital approach. After surgery, his eye abduction was improved in the primary position, and adduction ability was markedly restored on right gaze without diplopia. Conclusions: Our endonasal endoscopic approach provides excellent access to the MRM in the orbital retrobulbar space and avoids a facial scar. We could suture both ends of the muscle together by an endonasal endoscopic approach and could obtain a good result without any complications. ß 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Medial rectus muscle Endoscope Blowout fracture Endoscopic endonasal surgery
1. Introduction Rupture of the extraocular muscle is extremely rare, and a traumatic event is especially uncommon. Usually, post-traumatic diplopia is associated with penetrating orbital trauma or complex orbital fractures. The most frequently affected muscle is the medial rectus muscle (MRM) [1]. A few cases of traumatic MRM injury have been reported in the literature [1,2]; in many of them it was not possible to identify the posterior edge of the rectus muscle, and these cases underwent muscle transposition [1,3]. However, some cases had the ruptured MRM sutured, performed by an ophthalmologist using an external incision [4]. In the present report, we describe a surgical technique to repair a ruptured MRM using an endoscopic endonasal orbital (EEO) approach. 2. Surgical methods A 67-year-old man presented with an abnormal left eye position 4 months after a traffic accident. His left eye was fixed
* Corresponding author. Tel.: +81 87 891 2214; fax: +81 87 891 2215. E-mail address: [email protected] (K. Akiyama). http://dx.doi.org/10.1016/j.anl.2014.10.011 0385-8146/ß 2014 Elsevier Ireland Ltd. All rights reserved.
in the abduction position, and severely limited adduction was observed (Fig. 1A). Computerized tomography (CT) revealed a medial orbital wall fracture (medial type of blowout fracture: BOF), except for the third lamella bone, and discontinuity in the left MRM. This MRM was still attached to its anatomical insertion over the glove, but the discontinuity was suggestive of rupture approximately 10–12 mm from its insertion (Fig. 2). EEO was carried out under general anesthesia 5 months after injury. After performing a conventional endoscopic anterior ethmoidectomy and maxillary antrostomy, the fractured orbital medial wall and ethmoidal bone were lysed from the orbital content and removed gently. The posterior end of the ruptured MRM and its relationship to the basal lamella of the middle turbinate bone was carefully evaluated. We identified total rupture of the MRM approximately 12 mm from its insertion using the third lamella bone as a landmark. Then, we carefully lysed the basal lamella of the middle turbinate bone from the posterior end of the MRM. The orbital periosteum was cut horizontally postero-anteriorly along the assumed course of the MRM. Care was taken during the periosteum incision because the MRM is often close to the orbital medial wall. We lysed adhered fatty tissue after cutting the orbital periosteum and scar tissue. The anterior end of the MRM was not identified easily because the adhered fatty scar was extremely robust. We then
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Fig. 1. Clinical appearance of patient at initial evaluation (A) and 4 months after surgery (B). (A) The left eye shows slight abduction with no adduction movement on attempted right gaze. (B) Left eye abduction is improved in the primary position, and adduction ability is markedly restored on right gaze.
pulled the conjunctiva of his left eye horizontally, and part of the orbital fat, close to the MRM, was moved. We investigated this part of the orbital fat, and the anterior end of the MRM was identified. Although we tried to lyse orbital fat from this end of the muscle, it could not be achieved fully because extensive surgery could have damaged the eyeball, ophthalmic artery or optic nerve. We had to suture both ends of the MRM; however, both were extremely tough and could not be extended. As a result, we sutured both ends of the muscle with scarred fatty tissue. The posterior end of the ruptured muscle was sutured to its anterior end with doublearmed 6-0 Vicryl. Finally, a silicon sheet was inserted in the left middle meatus to replace and stabilize the orbital content (Fig. 3 and video). 3. Results No postoperative orbital neurological complications were observed. After 4 months of follow up, notable improvement of his eye movement and position was observed (Fig. 1B). Magnetic resonance imaging showed left MRM continuity (Fig. 4). The patient had no diplopia in any field of vision or enophthalmos. 4. Discussion An MRM injury can occur secondary to trauma or surgical complications, including strabismus, orbital, and endoscopic sinus surgery. Slipped and lost extraocular muscles are infrequently encountered in clinical practice but constitute complications of strabismus and other eye surgeries [5]. Extraocular muscle rupture following non-penetrating orbital trauma or BOF is especially
Fig. 2. Computed tomographic scan 4 months after a traffic accident. Left orbital medial wall is fractured, and left medial rectus muscle is ruptured by the left third lamella bone. Arrow indicates discontinuity of left MRM. Arrowhead indicates left third lamella bone.
uncommon. Knapp reported more than 60 cases of lost muscles, of which only 1 was related to trauma [6]. The most common individual muscle to be injured is the MRM, and the most commonly lost extraocular muscle is also the MRM [1]. However, a few cases of slipped or lost MRM retrieval have been reported in the literature: transposition of adjacent muscle was generally selected and only limited cases underwent suture of the ruptured rectus muscles [7]. The approach to the lost MRM has usually been the anterior approach, including transconjunctival subperiosteal medial orbitotomy [4,5] and transcutaneous medial orbitotomy [8]. McKeown et al. demonstrated in cadavers the feasibility of using a transnasal endoscopic approach to gain access to the MRM [9]. Thomas et al. reported retrieving a lost MRM with a combined transcutaneous medial orbitotomy and endoscopic approach [8]. In the report, an ophthalmologist sutured the muscle to the orbit with endoscopic assistance from an otolaryngologist. We could not select the retrieval method whereby the muscle is sutured to the glove or Tenon sleeve, because the posterior end of the MRM was adhered to fatty tissue, and consequently difficult to extract into the muscle capsule. Therefore, we attempted anastomosis of the ruptured MRM within the orbital retrobulbar space. We performed direct muscle-to-muscle anastomosis by the EEO approach, together with an otolaryngologist, in an obsolete traumatic complete rupture case. This approach has the advantage of avoiding a facial scar, and reduction surgeries for BOF can be performed concurrently in the same field. Additionally, missing muscles in the orbital retrobulbar space are sometimes difficult to identify by the anterior approach, whereas excellent access to the muscle is possible by the transnasal endoscopic orbital approach. We have reported the EEO procedure and described that the ethmoidomaxillary plate and the basal lamella of the middle turbinate bone are especially important landmarks for the endoscopic transethmoidal approach to the orbital retrobulbar space [10]. The third lamella on the medial orbital wall is located at an average of approximately 4 mm posterior to the end of the eyeball, and it is effective to confirm the depth of the orbita and the location of the retrobulbar space. The route via the ethmoidomaxillary plate on the orbital medial wall is considered a less dangerous approach to the orbita because the ethmoidomaxillary plate usually attaches inferior to the MRM [10]. Therefore, it is a useful landmark to decide the position of the orbital periosteum incision when the MRM is sought. In the present case, identification of the posterior end of the ruptured MRM was relatively easy because the third lamella was preserved and was helpful as a landmark. Surgeons need to ascertain the relationship of these landmarks to the orbital contents by CT imaging preoperatively. However, we did not use any navigation system in this case, although it would be safer and would facilitate surgery, as there is no characteristic structure in the intraorbital space, unlike the paranasal cavity.
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Fig. 3. During the operation. (A) The posterior side of the ruptured medial rectus muscle (MRM) was identified using the third lamella bone as a landmark. (B) Cutting the orbital periosteum. (C) Identification of the anterior end of the MRM. (D and E) A double-armed 6-0 Vicryl suture is passed through the posterior and anterior ends of the MRM. (F) Both ends of the muscle are sutured together. The surgical assistant applied tension to the end of the suture extranasally. III, third lamella bone; p-M, posterior side of ruptured MRM; a-M, anterior side of ruptured MRM; MT, middle turbinate; F, orbital fat.
Most surgeons prefer not to delay corrective surgery in order to avoid soft tissue scarring, fractured bone fusing, and contracture, all of which occur around the fracture sites in BOF cases [11]. Early retrieval of the injured extraocular muscle is also recommended [7]. Contracture of the ipsilateral antagonist can occur as early as 2 weeks after injury [7]. Our patient was more than 5 months posttrauma, and tough scarring was found around the ruptured muscle. Although pure muscle-to-muscle suture is always indicated, we sutured both ends of the muscle partially including scar tissue, because scars could not be detached completely from the muscle, particularly in its anterior end. After 4 months of follow-up, eye movement became normal and the patient reported no diplopia. Eye movement was normal in all positions. The reason for the delay in his eye movement improvement might have been the hard adhesions. We suggest that when there is a possibility of improving delayed cases, surgery should be performed. It is postulated that, whenever possible, early surgical treatment is desirable.
Huerva et al. also reported a complete MRM ruptured case which was repaired by muscle-to-muscle anastomosis, which also did not need additional salvage therapy [12]. Such ruptured cases are rare, and it may be difficult to weigh our indicated surgery against conventional methods. We think that muscle-to-muscle repair could be considered more physiological, if technical problems are cleared. 5. Conclusion We have described a surgical technique to repair a ruptured MRM with the endoscopic endonasal orbital approach, where good improvement was obtained despite it being an obsolete traumatic case. Financial disclosure None of the authors has any financial interests. Conflict of interest None.
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.anl.2014.10.011. References
Fig. 4. Magnetic resonance image 5 months after surgery. The left medial rectus muscle (arrow) shows continuity. Isointense lesion including the muscle (arrowhead) is presumably scar tissue adhered to the sutured muscle.
[1] Ling R, Quinn AG. Traumatic rupture of the medial rectus muscle. J AAPOS 2001;5:327–8. [2] Huerva V, Mateo AJ, Espinet R. Isolated medial rectus muscle rupture after a traffic accident. Strabismus 2008;16:33–7. [3] Bloom PA, Harrad R. Medial rectus rupture; a rare condition with an unusual presentation. J R Soc Med 1993;86:112–3.
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[4] Awad AH, Shin GS, Rosenbaum AL, Goldberg RL. Autogenous fascia augmentation of a partially extirpated muscle with a subperiosteal medial orbitotomy approach. J AAPOS 1997;1:138–42. [5] Cherfan CG, Traboulsi EI. Slipped, severed, torn and lost extraocular muscles. Can J Ophthalmol Journal canadien d‘ophtalmologie2011;46:501–9. [6] Knapp P. Lost muscle. In: Symposium on strabismus: transactions of the New Orleans Academy of Ophthalmology. St Louis: CV Mosby; 1978. p. 301–6. [7] Murray AD. Slipped and lost muscles and other tales of the unexpected. Philip Knapp Lecture. J AAPOS 1998;2:133–43. [8] Lenart TD, Reichman OS, McMahon SJ, Lambert SR. Retrieval of lost medial rectus muscles with a combined ophthalmologic and otolaryngologic surgical approach. Am J Ophthalmol 2000;130:645–52.
[9] McKeown CA, Metson RB, Dunya IM, Shore JW, Joseph MP. Transnasal endoscopic approach to expose the medial rectus from the annulus of Zinn to the penetration of Tenon’s capsule. J Pediatr Ophthalmol Strabismus 1996; 33:225–9. [10] Karaki M, Kobayashi R, Kobayashi E, Ishi G, Kagawa M, Tamiya T, et al. Computed tomographic evaluation of anatomic relationship between the paranasal structures and orbital contents for endoscopic endonasal transethmoidal approach to the orbit. Neurosurgery 2008;63:ONS15–19 [discussion ONS19–20]. [11] Farwell DG, Strong EB. Endoscopic repair of orbital floor fractures. Otolaryngol Clin North Am 2007;40:319–28. [12] Huerva V, Mateo AJ, Espinet R. Isolated medial rectus muscle rupture after a traffic accident. Strabismus 2008;16:33–7.
Contents lists available at ScienceDirect
Auris Nasus Larynx journal homepage: www.elsevier.com/locate/anl
Retrieval of ruptured medial rectus muscle with an endoscopic endonasal orbital approach. A case report and indication for surgical technique Kosuke Akiyama a,*, Masayuki Karaki b, Hiroshi Hoshikawaa a, Nozomu Mori a a b
Department of Otolaryngology, Faculty of Medicine, Kagawa University, Kita-gun, Miki-cho, Ikenobe 1750-1, Kagawa 761-0793, Japan Tanaka ENT Clinic, Tyuou-ku, Shinshigai 7-17, Kumamoto 860-0803, Japan
A R T I C L E I N F O
A B S T R A C T
Article history: Received 19 June 2014 Accepted 24 October 2014 Available online 16 November 2014
Introduction: Rupture of the extraocular muscle is extremely rare, and a traumatic event is especially uncommon. Although retrieval of an injured MRM is usually performed by an anterior approach by an ophthalmologist, missing muscles in the orbital retrobulbar space are sometimes difficult to identify. This is the first report to demonstrate direct muscle to muscle anastomosis by an endoscopic endonasal orbital approach by a single otolaryngologist. Case report: A 67-year-old man presented with left medial rectus muscle (MRM) rupture due to a traffic accident 4 months after injury. The MRM was completely ruptured, and the muscle was repaired by an endoscopic endonasal orbital approach. After surgery, his eye abduction was improved in the primary position, and adduction ability was markedly restored on right gaze without diplopia. Conclusions: Our endonasal endoscopic approach provides excellent access to the MRM in the orbital retrobulbar space and avoids a facial scar. We could suture both ends of the muscle together by an endonasal endoscopic approach and could obtain a good result without any complications. ß 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Medial rectus muscle Endoscope Blowout fracture Endoscopic endonasal surgery
1. Introduction Rupture of the extraocular muscle is extremely rare, and a traumatic event is especially uncommon. Usually, post-traumatic diplopia is associated with penetrating orbital trauma or complex orbital fractures. The most frequently affected muscle is the medial rectus muscle (MRM) [1]. A few cases of traumatic MRM injury have been reported in the literature [1,2]; in many of them it was not possible to identify the posterior edge of the rectus muscle, and these cases underwent muscle transposition [1,3]. However, some cases had the ruptured MRM sutured, performed by an ophthalmologist using an external incision [4]. In the present report, we describe a surgical technique to repair a ruptured MRM using an endoscopic endonasal orbital (EEO) approach. 2. Surgical methods A 67-year-old man presented with an abnormal left eye position 4 months after a traffic accident. His left eye was fixed
* Corresponding author. Tel.: +81 87 891 2214; fax: +81 87 891 2215. E-mail address: [email protected] (K. Akiyama). http://dx.doi.org/10.1016/j.anl.2014.10.011 0385-8146/ß 2014 Elsevier Ireland Ltd. All rights reserved.
in the abduction position, and severely limited adduction was observed (Fig. 1A). Computerized tomography (CT) revealed a medial orbital wall fracture (medial type of blowout fracture: BOF), except for the third lamella bone, and discontinuity in the left MRM. This MRM was still attached to its anatomical insertion over the glove, but the discontinuity was suggestive of rupture approximately 10–12 mm from its insertion (Fig. 2). EEO was carried out under general anesthesia 5 months after injury. After performing a conventional endoscopic anterior ethmoidectomy and maxillary antrostomy, the fractured orbital medial wall and ethmoidal bone were lysed from the orbital content and removed gently. The posterior end of the ruptured MRM and its relationship to the basal lamella of the middle turbinate bone was carefully evaluated. We identified total rupture of the MRM approximately 12 mm from its insertion using the third lamella bone as a landmark. Then, we carefully lysed the basal lamella of the middle turbinate bone from the posterior end of the MRM. The orbital periosteum was cut horizontally postero-anteriorly along the assumed course of the MRM. Care was taken during the periosteum incision because the MRM is often close to the orbital medial wall. We lysed adhered fatty tissue after cutting the orbital periosteum and scar tissue. The anterior end of the MRM was not identified easily because the adhered fatty scar was extremely robust. We then
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Fig. 1. Clinical appearance of patient at initial evaluation (A) and 4 months after surgery (B). (A) The left eye shows slight abduction with no adduction movement on attempted right gaze. (B) Left eye abduction is improved in the primary position, and adduction ability is markedly restored on right gaze.
pulled the conjunctiva of his left eye horizontally, and part of the orbital fat, close to the MRM, was moved. We investigated this part of the orbital fat, and the anterior end of the MRM was identified. Although we tried to lyse orbital fat from this end of the muscle, it could not be achieved fully because extensive surgery could have damaged the eyeball, ophthalmic artery or optic nerve. We had to suture both ends of the MRM; however, both were extremely tough and could not be extended. As a result, we sutured both ends of the muscle with scarred fatty tissue. The posterior end of the ruptured muscle was sutured to its anterior end with doublearmed 6-0 Vicryl. Finally, a silicon sheet was inserted in the left middle meatus to replace and stabilize the orbital content (Fig. 3 and video). 3. Results No postoperative orbital neurological complications were observed. After 4 months of follow up, notable improvement of his eye movement and position was observed (Fig. 1B). Magnetic resonance imaging showed left MRM continuity (Fig. 4). The patient had no diplopia in any field of vision or enophthalmos. 4. Discussion An MRM injury can occur secondary to trauma or surgical complications, including strabismus, orbital, and endoscopic sinus surgery. Slipped and lost extraocular muscles are infrequently encountered in clinical practice but constitute complications of strabismus and other eye surgeries [5]. Extraocular muscle rupture following non-penetrating orbital trauma or BOF is especially
Fig. 2. Computed tomographic scan 4 months after a traffic accident. Left orbital medial wall is fractured, and left medial rectus muscle is ruptured by the left third lamella bone. Arrow indicates discontinuity of left MRM. Arrowhead indicates left third lamella bone.
uncommon. Knapp reported more than 60 cases of lost muscles, of which only 1 was related to trauma [6]. The most common individual muscle to be injured is the MRM, and the most commonly lost extraocular muscle is also the MRM [1]. However, a few cases of slipped or lost MRM retrieval have been reported in the literature: transposition of adjacent muscle was generally selected and only limited cases underwent suture of the ruptured rectus muscles [7]. The approach to the lost MRM has usually been the anterior approach, including transconjunctival subperiosteal medial orbitotomy [4,5] and transcutaneous medial orbitotomy [8]. McKeown et al. demonstrated in cadavers the feasibility of using a transnasal endoscopic approach to gain access to the MRM [9]. Thomas et al. reported retrieving a lost MRM with a combined transcutaneous medial orbitotomy and endoscopic approach [8]. In the report, an ophthalmologist sutured the muscle to the orbit with endoscopic assistance from an otolaryngologist. We could not select the retrieval method whereby the muscle is sutured to the glove or Tenon sleeve, because the posterior end of the MRM was adhered to fatty tissue, and consequently difficult to extract into the muscle capsule. Therefore, we attempted anastomosis of the ruptured MRM within the orbital retrobulbar space. We performed direct muscle-to-muscle anastomosis by the EEO approach, together with an otolaryngologist, in an obsolete traumatic complete rupture case. This approach has the advantage of avoiding a facial scar, and reduction surgeries for BOF can be performed concurrently in the same field. Additionally, missing muscles in the orbital retrobulbar space are sometimes difficult to identify by the anterior approach, whereas excellent access to the muscle is possible by the transnasal endoscopic orbital approach. We have reported the EEO procedure and described that the ethmoidomaxillary plate and the basal lamella of the middle turbinate bone are especially important landmarks for the endoscopic transethmoidal approach to the orbital retrobulbar space [10]. The third lamella on the medial orbital wall is located at an average of approximately 4 mm posterior to the end of the eyeball, and it is effective to confirm the depth of the orbita and the location of the retrobulbar space. The route via the ethmoidomaxillary plate on the orbital medial wall is considered a less dangerous approach to the orbita because the ethmoidomaxillary plate usually attaches inferior to the MRM [10]. Therefore, it is a useful landmark to decide the position of the orbital periosteum incision when the MRM is sought. In the present case, identification of the posterior end of the ruptured MRM was relatively easy because the third lamella was preserved and was helpful as a landmark. Surgeons need to ascertain the relationship of these landmarks to the orbital contents by CT imaging preoperatively. However, we did not use any navigation system in this case, although it would be safer and would facilitate surgery, as there is no characteristic structure in the intraorbital space, unlike the paranasal cavity.
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Fig. 3. During the operation. (A) The posterior side of the ruptured medial rectus muscle (MRM) was identified using the third lamella bone as a landmark. (B) Cutting the orbital periosteum. (C) Identification of the anterior end of the MRM. (D and E) A double-armed 6-0 Vicryl suture is passed through the posterior and anterior ends of the MRM. (F) Both ends of the muscle are sutured together. The surgical assistant applied tension to the end of the suture extranasally. III, third lamella bone; p-M, posterior side of ruptured MRM; a-M, anterior side of ruptured MRM; MT, middle turbinate; F, orbital fat.
Most surgeons prefer not to delay corrective surgery in order to avoid soft tissue scarring, fractured bone fusing, and contracture, all of which occur around the fracture sites in BOF cases [11]. Early retrieval of the injured extraocular muscle is also recommended [7]. Contracture of the ipsilateral antagonist can occur as early as 2 weeks after injury [7]. Our patient was more than 5 months posttrauma, and tough scarring was found around the ruptured muscle. Although pure muscle-to-muscle suture is always indicated, we sutured both ends of the muscle partially including scar tissue, because scars could not be detached completely from the muscle, particularly in its anterior end. After 4 months of follow-up, eye movement became normal and the patient reported no diplopia. Eye movement was normal in all positions. The reason for the delay in his eye movement improvement might have been the hard adhesions. We suggest that when there is a possibility of improving delayed cases, surgery should be performed. It is postulated that, whenever possible, early surgical treatment is desirable.
Huerva et al. also reported a complete MRM ruptured case which was repaired by muscle-to-muscle anastomosis, which also did not need additional salvage therapy [12]. Such ruptured cases are rare, and it may be difficult to weigh our indicated surgery against conventional methods. We think that muscle-to-muscle repair could be considered more physiological, if technical problems are cleared. 5. Conclusion We have described a surgical technique to repair a ruptured MRM with the endoscopic endonasal orbital approach, where good improvement was obtained despite it being an obsolete traumatic case. Financial disclosure None of the authors has any financial interests. Conflict of interest None.
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.anl.2014.10.011. References
Fig. 4. Magnetic resonance image 5 months after surgery. The left medial rectus muscle (arrow) shows continuity. Isointense lesion including the muscle (arrowhead) is presumably scar tissue adhered to the sutured muscle.
[1] Ling R, Quinn AG. Traumatic rupture of the medial rectus muscle. J AAPOS 2001;5:327–8. [2] Huerva V, Mateo AJ, Espinet R. Isolated medial rectus muscle rupture after a traffic accident. Strabismus 2008;16:33–7. [3] Bloom PA, Harrad R. Medial rectus rupture; a rare condition with an unusual presentation. J R Soc Med 1993;86:112–3.
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[4] Awad AH, Shin GS, Rosenbaum AL, Goldberg RL. Autogenous fascia augmentation of a partially extirpated muscle with a subperiosteal medial orbitotomy approach. J AAPOS 1997;1:138–42. [5] Cherfan CG, Traboulsi EI. Slipped, severed, torn and lost extraocular muscles. Can J Ophthalmol Journal canadien d‘ophtalmologie2011;46:501–9. [6] Knapp P. Lost muscle. In: Symposium on strabismus: transactions of the New Orleans Academy of Ophthalmology. St Louis: CV Mosby; 1978. p. 301–6. [7] Murray AD. Slipped and lost muscles and other tales of the unexpected. Philip Knapp Lecture. J AAPOS 1998;2:133–43. [8] Lenart TD, Reichman OS, McMahon SJ, Lambert SR. Retrieval of lost medial rectus muscles with a combined ophthalmologic and otolaryngologic surgical approach. Am J Ophthalmol 2000;130:645–52.
[9] McKeown CA, Metson RB, Dunya IM, Shore JW, Joseph MP. Transnasal endoscopic approach to expose the medial rectus from the annulus of Zinn to the penetration of Tenon’s capsule. J Pediatr Ophthalmol Strabismus 1996; 33:225–9. [10] Karaki M, Kobayashi R, Kobayashi E, Ishi G, Kagawa M, Tamiya T, et al. Computed tomographic evaluation of anatomic relationship between the paranasal structures and orbital contents for endoscopic endonasal transethmoidal approach to the orbit. Neurosurgery 2008;63:ONS15–19 [discussion ONS19–20]. [11] Farwell DG, Strong EB. Endoscopic repair of orbital floor fractures. Otolaryngol Clin North Am 2007;40:319–28. [12] Huerva V, Mateo AJ, Espinet R. Isolated medial rectus muscle rupture after a traffic accident. Strabismus 2008;16:33–7.
