- Email: [email protected]
Arthroscopic resection of symptomatic “os trigonum”
FussSprungg 4:112–117 (2006) DOI 10.1007/s10302-006-0158-8
CASE REPORT
M. E. M. Fadel J. Jerosch
Arthroscopic resection of symptomatic ”os trigonum“ Report of 2 cases
Arthroskopische Resektion eines symptomatischen Os trigonum " Zusammenfassung Ein symptomatisches Os trigonum ist eine nicht seltene Ursache für Beschwerden im posterioren Sprunggelenksbereich. Dies trifft vor allem Sportler und Tänzer.
Received: 28 December 2004 Accepted: 25 January 2005
Prof. Dr. med. Dr. h.c. Jörg Jerosch ()) Klinik für Orthopädie und Orthopädische Chirurgie Johanne-Etienne-Klinik Am Hasenberg 46 41462 Neuss, Germany Tel.: + 49-21 31 / 5 29-20 01 Fax: + 49-21 31 / 5 29 20 15 E-Mail: [email protected] Mohie Eldin Mahmound Fadel Alexandria University Alexandria, Egypt
Das Os trigonum ist ein sekundäres Ossifikationszentrum des Talus lateral des Sulcus für den Flexor hallucis longus. Es findet sich mit einer Inzidenz von 1,7% bis 7%. Klinische Beschwerden können sich aufgrund von entzündlichen Veränderungen oder nach einem Unfall manifestieren. Arthroskopische Therapieformen ersetzen auch hier offene OP-Verfahren und können so iatrogene Begleitschäden reduzieren. Das Ziel der vorliegenden Arbeit ist es die Operationstechnik der biportalen arthroskopischen Resektion eines symptomatischen Os trigonum darzustellen und gleichzeitig die klinischen Ergebnisse bei zwei Patienten zu präsentieren. " Schlüsselwörter Os trigonum – posteriores Sprunggelenksimpingement – posteriore Sprunggelenksarthroskopie " Summary Symptomatic ”os trigonum“ is not an uncommon
Introduction Posterior ankle pain can result from many causes and may represent a diagnostic challenge. Symptomatic os trigonum is not an uncommon cause for posterior ankle pain and usually affects athletes and ballerinas.
FussSprungg 2
2006
cause for posterior ankle pain and usually affects athletes and ballerinas. The ”os trigonum“ is a secondary center of ossification of the talus lateral to the groove for the flexor hallucis longus. It is present in 1.7% to 7% of normal feet. Os trigonum syndrome may manifest as inflammation of the posterior ankle soft tissues, as an osseous injury, or as a combination of both. Arthroscopic techniques have been substituted for open operative techniques in many diseases to avoid complications associated with open surgical techniques. The purpose of this study was to describe the technique of arthroscopic resection of symptomatic os trigonum through two posterior portals in two cases and also to evaluate the safety and clinical results of this technique " Key words Os trigonum – posterior ankle impingement – posterior ankle arthroscopy
The os trigonum is a secondary center of ossification of the talus lateral to the groove for the flexor hallucis longus [1, 2]. Grogan et al. [3] observed upon histological analysis that this ossification center forms within a cartilaginous extension from the posterior portion of the talus. It appears between the ages of 11 and 13 in boys and 8 and 10 years in girls [1]. It is present in 1.7% to 7% of normal feet [4].
Arthroscopic resection of symptomatic ”os trigonum“
Normally, this ossification center fuses with the rest of the talus within 1 year of its appearance [1]. However, if this ossification center remains separate; it is referred to as the os trigonum [5].When fusion does occur and there is a large intact posterolateral talar process, it is referred to as a fused os trigonum [6], a Stieda process [7], or a trigonal process [8]. It is bilateral in approximately 1.4% of individuals [9]. The os trigonum is totally corticated and articulates with the lateral talar tubercle through a synchondrosis. Since Rosenmuller first described the os trigonum in 1804 [7], there has been controversy concerning its origin. Steida [10] and Turner [11] believed it to be a secondary ossification center of the talus, whereas Shepherd [12] and Moullin [1] stated that it is an ununited fracture of the posterolateral talar process. Forced plantar flexion causes impingement of the os trigonum between the posterior part of the tibial plafond and superior process of the calceneous [7, 13]. Os trigonum syndrome may manifest as inflammation of the posterior ankle soft tissues, as an osseous injury, or as a combination of both [14]. The osseous injuries include fracture, fragmentation, and pseudoarthrosis of the os trigonum or lateral talar tubercle [14–16].While soft tissue affection may involve FHL tendonitis. The term os trigonum is often used inappropriately. A symptomatic os trigonum, which is characterized mainly by posterior ankle pain, has been given many different names, including talar compression syndrome [7], posterior ankle block [17], posterior ankle impingement, and os trigonum syndrome [1, 5]. Arthroscopic techniques have been substituted for open operative techniques in many diseases to avoid complications associated with open surgical techniques. Ankle arthroscopy is a surgical technique that can be used to diagnose and treat articular lesions of the ankle and subtalar joint at the same time. It is less aggressive and offers better diagnostic accuracy than the open technique [18–21]. The purpose of this study was to describe the technique of arthroscopic resection of symptomatic os trigonum through two posterior portals and also to evaluate the safety and clinical results of this technique.
113
tory of acute trauma nor a response to conservative treatment. They were not able to continue their sport activities. Both cases showed tenderness over the postero-lateral aspect of the ankle joint. They showed classical pain with maximum planter flexion of the ankle. There was no tenderness over the peroneal tendons or the lateral ligaments of the ankle. There were no signs of ankle instability.
Imaging findings (Figs. 1–3) Preoperative lateral radiographs revealed united os trigonum in the first case and nonunited os trigonum in the second case. MRI of the patients revealed bone marrow edema in the area of os trigonum in both cases and syndesmosis between the nonunited os trigonum and lateral process of the talus in the second case.
Fig. 1 Lateral x-ray of the first case
Patients The first case was a 25-year-old female competitive hockey player, who had posterior ankle pain over a period of 12 months, while the second case was a 19-year-old female Olympic water polo player, who had posterior ankle pain for 6 months. The onset of pain in the two cases was gradual. Neither had a his-
Fig. 2 MRI of the first case shows bone marrow edema in the area of the os trigonum
FussSprungg 2
2006
114
M. E. M. Fadel and J. Jerosch
Fig. 3 MRI of the second case shows nonunion area of os trigonum and bone marrow edema
Surgical technique
Results
The patients were placed in the prone position. The patient’s feet were pulled away from the table to allow free ankle movement. The nonoperated foot was placed lower than the operated leg, which makes manipulation of the instruments easier. A tourniquet was applied. The posterolateral portal was made by stab incision through skin just lateral to the achillis tendon at the level of the tibiotalar joint at the tip of the lateral malleolus or slightly above, then blunt dissection with a clamp in the anterior direction to the bone. Blunt trocar with the shaft of the arthroscope was introduced in the same direction. The level of the tibiotalar joint could be determined by palpating the bone alon the sagittal plane. The blunt trocar was removed and a 30 degree arthroscope was introduced. The posteromedial portal was made just medial to achillis tendon at the same level of the posterolateral portal. A spinal needle was inserted through the skin and directed to anterior tip of arthroscope to be visualized. The needle was removed and a stab skin incision was made, then a blunt dissection with a clamp all the way to the bone until the tip of the clamp came into view was performed. Identification of the flexor hallucis longus tendon including the joint capsule, and posterior tibiofibular joint, is a major step. Debridment of the soft tissue with a shaver, identification of os trigonum and resection by acromonizer (Fig. 4 A, B, C) were performed. Synovectomy of the FHL was done in both cases. Inspection of the ankle and subtalar joint were performed to exclude other intra-articular pathologies. Post-operatively, no plaster cast or splint was applied to the foot and bearing of weight was allowed on the second post-operative day.
Both patients were symptom-free within 2 weeks post-operation. They resumed their professional sport activities after a period of 4 weeks. The first patient with a longer follow-up period o f 24 months and the second patient with a 6-month follow-up showed no complications or recurrent symptoms.
FussSprungg 2
2006
Discussion Posterior ankle impingement syndrome (PAI) refers to a group of pathologic entities that result from repetitive or acute forced planter flexion [15]. This syndrome has been extensively described in classical ballet dancers [23, 24], but it also has been described in individuals who are active in sports, including soccer, basketball, running, and volleyball, as well as in those who participate in non-sport-related activities [7, 15]. The condition arises from compression of the soft tissues between the posterior process of the calceneus and the posterior tibia upon planter flexion of the ankle. The lateral posterior process of the talus is also important because if this is prominent or if an os trigonum is present, additional bony impingement with these structures can occur [25, 26]. Diagnosis of PAI is based primarily on patient clinical history and physical examination [14]. It is supported by radiographic findings. Scintigraphy can effectively localize osseous injuries in and around the talus [27]. A computed tomography scan enables the surgeon to determine the exact location, size, and shape of the ossicle, but it is less sensitive for detection of soft tissue involvement [28]. MRI is useful in the assessment of PAI; it clearly depicts the soft tissue abnormalities associated with PAI syndrome. It could also manifest bone marrow edema, a fracture line, or fluid in synchondrosis (in-
Arthroscopic resection of symptomatic ”os trigonum“
A
B
C Fig. 4 A Os trigonum after soft tissue debridment. B Resection with acromonizer. C After resection
dicating os trigonum fracture), posterior capsular or ligament thickening with intermediate or low signal intensity on T2-weighted images [13, 25, 26]. When conservative treatment fails to decrease the symptoms of os trigonum syndrome, surgical excision of the ossicle is the treatment of choice [1, 28]. Stenosing tenosynovitis of the flexor hallucis longus tendon may coexist with os trigonum syndrome,
115
usually when the condition is chronic, as in ballet dancers; this leads to poorer outcome if surgical treatment is delayed [1, 7, 28]. When an open procedure is used, the surgical approach used to excise the ossicle is controversial. The posterolateral approach is easier and safer than the medial approach [7, 28]. The disadvantage of posterolateral approach is the relatively high number of sural nerve complications reported. Arthroscopy of the ankle is now a well-established procedure used for both accurate diagnosis and operative management of certain ankle disorders. Since Burman’s [29] first description in 1931, ankle arthroscopy has continued to present new challenges. Improvements in the technique and methods have expanded the indications for ankle arthroscopy. Many reports in the literatures dealing with lateral ankle ligament injuries and anterior ankle lesions are available. Pathologies of the posterior ankle are published comparatively rarely. Although anterior and posterior portals for ankle arthroscopy have been well documented [30, 33], the standard posteromedial portal has recognized risks because of the proximity of the posterior neurovascular structures [34, 35]. Several investigators have reported technical difficulties in addressing posterior ankle synovectomy [36, 37]. The posterolateral approach has been advocated by some authors in combination with routine anterior ankle arthroscopy [38, 39]; this makes systemic assessment of the posterior ankle joint possible but instrumentation from the front to the back of the joint is difficult. This also allows only intra-articular pathology to be assessed. Periarticular pathology, such as post-traumatic calcifications, periarticular scar tissue, symptomatic os trigonum, or FHL can not be assessed [20]. Frekel et al. [40] reported on a large consecutive series of 612 ankle arthroscopies; they recommended placement of the patient in the supine position and the use of antrolateral, anteromedial and posterolateral portals for routine procedures. They stated that anterocentral, transachillis, and posteromedial portals should never be used because of the potential neurovascular and tendon injury. Voto et al. [35] noted that the posteromedial portal is potentially hazardous even if placed adjacent to the achillis tendon, because of the location of neurovascular bundle. Recent anatomical and clinical studies have showed that the postero-medial portal for ankle arthroscopy is safe as well as the well established postero-lateral portal. Finally, Parisien et al. [37], in cadaveric study, noted that posterior lesions and loose bodies within the posterior pouch where seen better and were treated more effectively through two posterior portals when the limb was in the prone position.
FussSprungg 2
2006
116
M. E. M. Fadel and J. Jerosch
Feiwell and Frey [34] showed the posteromedial portal to be an average 7.5 mm from posterior tibial nerve with actual contact in some cases and also reported that the average distance between the posterolateral portal and the sural nerve was 6.0 mm. Acevedo et al. [41], in a cadaveric anatomic study, described a new coaxial procedure with two posterior portals for ankle arthroscopy with no cases of penetration or contact of any of the posterior neurovascular structures, neither medially nor laterally. Van Dijk et al. [20] reported 86 consecutive endoscopic hindfoot procedures through 2 posterior portals without any complications. Abramowitz et al. [28], demonstrated in his study on 41 patients undergoing open os trigonum resection, that the clinical outcome is similar between open and arthroscopic approaches, whereby the advantage of arthroscopy is early ambulation and healing and more patient satisfaction. In open techniques, the time to full recovery averaged five months and ranged from one to twelve months [7, 23, 28]. Van Dijk et al. [20] described only one case of arthrscopic treatment of os trigonum with excellent results. The average postoperative AOFAS score for eleven patients treated with arthroscopic excision in
the clinical series reported by Marumoto and Ferkel [21] was 86.4 points. In this study we used the two posterior portals of the ankle (posteromedial and posterolateral) to perform complete resection of symptomatic os trigonum in two young females in competitive sports. Both patients were pain-free within 2 weeks post-operation. They resumed their professional sport activities after a period of 4 weeks. There were neither complications nor recurrent symptoms recorded.
Conclusion We concluded that arthroscopic removal of symptomatic os trigonum through two posterior portals is an effective and safe treatment and facilitates early rehabilitation. It also allows dynamic tests and assessment of intra-articular pathology. We also believe that a high level of suspicion and early diagnosis and treatment os trigonum syndrome are important not only to relieve current pain but also to improve the prognosis. More prospective studies on a larger number of patients is needed.
References 1. McDougall A (1955) The os trigonum. J Bone JointSurg Br 37:257–265 2. Mann RW, Owsley DW (1990) Os trigonum. Variation of a common accessory ossicle of the talus. J Am Podiatr Med Assoc 80:536–539 3. Grogan DP, Walling AK, Ogden JA (1990) Anatomy of the os trigonum. J Pediatr Orthop 10:618–622 4. Bizarro AH (1921) On sesamoid and supernumerary bones of the limbs. J Anat 55:256–268 5. Quirk R (1994) Commom foot and ankle injuries in dance. Orthop clin north am 25:123–133 6. Burman MS, Lapidus PW (1931) The functional disturbances caused by the inconstant bones and sesamoids of the foot. Arch Surg 22:936–975 7. Brodsky AE, Khalil MA (1986) Talar compression syndrome. Am J Sports Med 14:472–476 8. Sarrafian SK (1983) Anatomy of the foot and ankle: descriptive, topographic, functional. Lippincott, Philadelphia, pp 18, 52-3, 94 9. Lapidus PW (1972) A note on fracture of the os trigonm syndrome. Bull Hosp Joint Dis 33:150–154
FussSprungg 2
2006
10. Stieda L (1869) Über secondäre Fußwurzelknochen. Arch phsiol WissenechMed 108:111 11. Turner W (1882) A secondary astragalus in the human foot. J Anat Physiol 17:82–83 12. Shepherd FJ (1882) A hitherto undescribed fracture of the astragalus. J Anat Physiol 17:79–81 13. Bureauf NJ, Cardinal E, Hobden R, Aubin B (2000) Posterior ankle impingement syndrome: MR imaging findings in seven patient. Radiology 215(2):497–503 14. Blake RL, Lxllas RJ, Ferguson H (1992) The os trigonum syndrome: a literature review. J Am Podiatr Med Assoc 82:154–161 15. Hedrick MR, McBryde AM (1994) Posterior ankle impingement. Foot Ankle Int 15:2–8 16. Martin BF (1989) Posterior triangle pain: the os trigonum. J Foot Surg 28:312–318 17. Howse AJ (1982) Posterior block of the ankle joint in dancers. Foot Ankle 3:81–84 18. Feiwell LA, Frey C (1993) Anatomic study of arthroscopic portal sites of the ankle. Foot Ankle 14:142–147
19. Ferkel RD, Fasulo GJ (1994) Arthroscopic treatment of ankle injuries. Orthop Clin North Am 25:17–32 20. Van Dijk CN, Scholten PE, Krips R (2000) A 2-portal endoscopic approach for diagnosis and treatment of posterior ankle pathology. Arthroscopy 16:871–876 21. Marumoto JM, Ferkel RD (1997) Arthroscopic excision of the os trigonum: A new technique with preliminary clinical results. Foot Ankle 18:777–784 22. Lohrer H, Arentz S (2004) Posterior approach for arthroscopic treatment of posterolateral impingement syndrome of the ankle in a top-level field hockey player, A case report. Arthroscopy 20:e15–e21 23. Hamilton WG, Geppert MJ, Thompson FM (1996) Posterior aspect of the ankle in dancers: differential diagnosis and operative treatment. J Bone Joint Surg Am 78:1491–1500 24. Marotta JJ, Micheli LJ (1992) Os trigonum impingement in dancers. Am J Sports Med 20:533–536 25. Karasick D, Schweitzer ME (1996) The os thgonum syndrome: imaging features. Am Roenrgenol l66:125–129
Arthroscopic resection of symptomatic ”os trigonum“
26. Wakeley CJ, Johnson DP, Watt I (1996) The value of MR imaging in the diagnosis of the os trigonum syndrome. Skeletal Radiol 25:133–136 27. Johnson RP, Collier D, Carrera GF (1984) The os trigonum syndrome: use of bone scan in the diaqosis. J Trauma 24:761–764 28. Abramowitz Y, Wollstein R, Barazilay Y, London E, Matan Y, Shabat S, Nyska M, MD (2003) Outcome of the resection of a symptomatic os trigonum. J Bone Joint Surg Am 85:1051– 1057 29. Burman MS (1985) Arthroscopy of direct visualization of joints: An experimental cadaveric study. J Bone Joint Surg 13:669 30. Andrews JR, Previte WJ, Carson WG (1985) Arthroscopy of the ankle: Technique and normal anatomy. Foot Ankle 6:29–33 31. Drez D, Guhl JF, Gollehon DL (1981) Ankle arthroscopy: Techniques and indications. Foot Ankle 2:138–143
117
32. Guhl JF (1986) New techniques for arthroscopic surgery of the ankle: Preliminary report. Orthopedics 9: 261–269 33. Parisien JS, Vangsness T (1985) Operative arthroscopy of the ankle: Three years’ experience. Clin Orthop 199:46–53 34. Feiwell LA, Frey C (1993) Anatomic study of arthroscopic portal sites of the ankle. Foot Ankle 14:142–147 35. Voto SJ, Ewing JW, Fleissner PR (1989) Ankle arthroscopy: Neurovascular and arthroscopic anatomy of standard and trans-Achilles tendon portal placement. Arthroscopy 5:41– 46 36. Ferkel RD (1993) Arthroscopy of the ankle and foot. In: Mann RA, Coghlin MJ (eds) Surgery of the foot and ankle. Vol 2, Ed 6. Mosby, St. Louis, pp 1277–1310
37. Parisien JS, Vangsness T, Feldman R (1987) Diagnostic and operative arthroscopy of the ankle: An experimental approach. Clin Orthop 224:228–236 38. Ferkel RD, Fischer SP (1989) Progress in ankle anhroscopy. Clin Orthop Res 240:210–220 39. Ferkel RD, Scranton PE Jr (1993) Athroscopy of dIe ankle and foot. J Bone Joint Surg Am 75:1233–1242 40. Ferkel RD, Heath DD, Guhl JF (1996) Neurological complications of ankle arthroscopy. Arthroscopy 12:200–208 41. Acevedo JI, Busch MT, Ganey TM, Hutton WC, Ogden JA (2000) Coaxial portals for posterior ankle arthroscopy: an anatomic study with clinical correlation on 29 patients. Arthroscopy 16:836–842
FussSprungg 2
2006
CASE REPORT
M. E. M. Fadel J. Jerosch
Arthroscopic resection of symptomatic ”os trigonum“ Report of 2 cases
Arthroskopische Resektion eines symptomatischen Os trigonum " Zusammenfassung Ein symptomatisches Os trigonum ist eine nicht seltene Ursache für Beschwerden im posterioren Sprunggelenksbereich. Dies trifft vor allem Sportler und Tänzer.
Received: 28 December 2004 Accepted: 25 January 2005
Prof. Dr. med. Dr. h.c. Jörg Jerosch ()) Klinik für Orthopädie und Orthopädische Chirurgie Johanne-Etienne-Klinik Am Hasenberg 46 41462 Neuss, Germany Tel.: + 49-21 31 / 5 29-20 01 Fax: + 49-21 31 / 5 29 20 15 E-Mail: [email protected] Mohie Eldin Mahmound Fadel Alexandria University Alexandria, Egypt
Das Os trigonum ist ein sekundäres Ossifikationszentrum des Talus lateral des Sulcus für den Flexor hallucis longus. Es findet sich mit einer Inzidenz von 1,7% bis 7%. Klinische Beschwerden können sich aufgrund von entzündlichen Veränderungen oder nach einem Unfall manifestieren. Arthroskopische Therapieformen ersetzen auch hier offene OP-Verfahren und können so iatrogene Begleitschäden reduzieren. Das Ziel der vorliegenden Arbeit ist es die Operationstechnik der biportalen arthroskopischen Resektion eines symptomatischen Os trigonum darzustellen und gleichzeitig die klinischen Ergebnisse bei zwei Patienten zu präsentieren. " Schlüsselwörter Os trigonum – posteriores Sprunggelenksimpingement – posteriore Sprunggelenksarthroskopie " Summary Symptomatic ”os trigonum“ is not an uncommon
Introduction Posterior ankle pain can result from many causes and may represent a diagnostic challenge. Symptomatic os trigonum is not an uncommon cause for posterior ankle pain and usually affects athletes and ballerinas.
FussSprungg 2
2006
cause for posterior ankle pain and usually affects athletes and ballerinas. The ”os trigonum“ is a secondary center of ossification of the talus lateral to the groove for the flexor hallucis longus. It is present in 1.7% to 7% of normal feet. Os trigonum syndrome may manifest as inflammation of the posterior ankle soft tissues, as an osseous injury, or as a combination of both. Arthroscopic techniques have been substituted for open operative techniques in many diseases to avoid complications associated with open surgical techniques. The purpose of this study was to describe the technique of arthroscopic resection of symptomatic os trigonum through two posterior portals in two cases and also to evaluate the safety and clinical results of this technique " Key words Os trigonum – posterior ankle impingement – posterior ankle arthroscopy
The os trigonum is a secondary center of ossification of the talus lateral to the groove for the flexor hallucis longus [1, 2]. Grogan et al. [3] observed upon histological analysis that this ossification center forms within a cartilaginous extension from the posterior portion of the talus. It appears between the ages of 11 and 13 in boys and 8 and 10 years in girls [1]. It is present in 1.7% to 7% of normal feet [4].
Arthroscopic resection of symptomatic ”os trigonum“
Normally, this ossification center fuses with the rest of the talus within 1 year of its appearance [1]. However, if this ossification center remains separate; it is referred to as the os trigonum [5].When fusion does occur and there is a large intact posterolateral talar process, it is referred to as a fused os trigonum [6], a Stieda process [7], or a trigonal process [8]. It is bilateral in approximately 1.4% of individuals [9]. The os trigonum is totally corticated and articulates with the lateral talar tubercle through a synchondrosis. Since Rosenmuller first described the os trigonum in 1804 [7], there has been controversy concerning its origin. Steida [10] and Turner [11] believed it to be a secondary ossification center of the talus, whereas Shepherd [12] and Moullin [1] stated that it is an ununited fracture of the posterolateral talar process. Forced plantar flexion causes impingement of the os trigonum between the posterior part of the tibial plafond and superior process of the calceneous [7, 13]. Os trigonum syndrome may manifest as inflammation of the posterior ankle soft tissues, as an osseous injury, or as a combination of both [14]. The osseous injuries include fracture, fragmentation, and pseudoarthrosis of the os trigonum or lateral talar tubercle [14–16].While soft tissue affection may involve FHL tendonitis. The term os trigonum is often used inappropriately. A symptomatic os trigonum, which is characterized mainly by posterior ankle pain, has been given many different names, including talar compression syndrome [7], posterior ankle block [17], posterior ankle impingement, and os trigonum syndrome [1, 5]. Arthroscopic techniques have been substituted for open operative techniques in many diseases to avoid complications associated with open surgical techniques. Ankle arthroscopy is a surgical technique that can be used to diagnose and treat articular lesions of the ankle and subtalar joint at the same time. It is less aggressive and offers better diagnostic accuracy than the open technique [18–21]. The purpose of this study was to describe the technique of arthroscopic resection of symptomatic os trigonum through two posterior portals and also to evaluate the safety and clinical results of this technique.
113
tory of acute trauma nor a response to conservative treatment. They were not able to continue their sport activities. Both cases showed tenderness over the postero-lateral aspect of the ankle joint. They showed classical pain with maximum planter flexion of the ankle. There was no tenderness over the peroneal tendons or the lateral ligaments of the ankle. There were no signs of ankle instability.
Imaging findings (Figs. 1–3) Preoperative lateral radiographs revealed united os trigonum in the first case and nonunited os trigonum in the second case. MRI of the patients revealed bone marrow edema in the area of os trigonum in both cases and syndesmosis between the nonunited os trigonum and lateral process of the talus in the second case.
Fig. 1 Lateral x-ray of the first case
Patients The first case was a 25-year-old female competitive hockey player, who had posterior ankle pain over a period of 12 months, while the second case was a 19-year-old female Olympic water polo player, who had posterior ankle pain for 6 months. The onset of pain in the two cases was gradual. Neither had a his-
Fig. 2 MRI of the first case shows bone marrow edema in the area of the os trigonum
FussSprungg 2
2006
114
M. E. M. Fadel and J. Jerosch
Fig. 3 MRI of the second case shows nonunion area of os trigonum and bone marrow edema
Surgical technique
Results
The patients were placed in the prone position. The patient’s feet were pulled away from the table to allow free ankle movement. The nonoperated foot was placed lower than the operated leg, which makes manipulation of the instruments easier. A tourniquet was applied. The posterolateral portal was made by stab incision through skin just lateral to the achillis tendon at the level of the tibiotalar joint at the tip of the lateral malleolus or slightly above, then blunt dissection with a clamp in the anterior direction to the bone. Blunt trocar with the shaft of the arthroscope was introduced in the same direction. The level of the tibiotalar joint could be determined by palpating the bone alon the sagittal plane. The blunt trocar was removed and a 30 degree arthroscope was introduced. The posteromedial portal was made just medial to achillis tendon at the same level of the posterolateral portal. A spinal needle was inserted through the skin and directed to anterior tip of arthroscope to be visualized. The needle was removed and a stab skin incision was made, then a blunt dissection with a clamp all the way to the bone until the tip of the clamp came into view was performed. Identification of the flexor hallucis longus tendon including the joint capsule, and posterior tibiofibular joint, is a major step. Debridment of the soft tissue with a shaver, identification of os trigonum and resection by acromonizer (Fig. 4 A, B, C) were performed. Synovectomy of the FHL was done in both cases. Inspection of the ankle and subtalar joint were performed to exclude other intra-articular pathologies. Post-operatively, no plaster cast or splint was applied to the foot and bearing of weight was allowed on the second post-operative day.
Both patients were symptom-free within 2 weeks post-operation. They resumed their professional sport activities after a period of 4 weeks. The first patient with a longer follow-up period o f 24 months and the second patient with a 6-month follow-up showed no complications or recurrent symptoms.
FussSprungg 2
2006
Discussion Posterior ankle impingement syndrome (PAI) refers to a group of pathologic entities that result from repetitive or acute forced planter flexion [15]. This syndrome has been extensively described in classical ballet dancers [23, 24], but it also has been described in individuals who are active in sports, including soccer, basketball, running, and volleyball, as well as in those who participate in non-sport-related activities [7, 15]. The condition arises from compression of the soft tissues between the posterior process of the calceneus and the posterior tibia upon planter flexion of the ankle. The lateral posterior process of the talus is also important because if this is prominent or if an os trigonum is present, additional bony impingement with these structures can occur [25, 26]. Diagnosis of PAI is based primarily on patient clinical history and physical examination [14]. It is supported by radiographic findings. Scintigraphy can effectively localize osseous injuries in and around the talus [27]. A computed tomography scan enables the surgeon to determine the exact location, size, and shape of the ossicle, but it is less sensitive for detection of soft tissue involvement [28]. MRI is useful in the assessment of PAI; it clearly depicts the soft tissue abnormalities associated with PAI syndrome. It could also manifest bone marrow edema, a fracture line, or fluid in synchondrosis (in-
Arthroscopic resection of symptomatic ”os trigonum“
A
B
C Fig. 4 A Os trigonum after soft tissue debridment. B Resection with acromonizer. C After resection
dicating os trigonum fracture), posterior capsular or ligament thickening with intermediate or low signal intensity on T2-weighted images [13, 25, 26]. When conservative treatment fails to decrease the symptoms of os trigonum syndrome, surgical excision of the ossicle is the treatment of choice [1, 28]. Stenosing tenosynovitis of the flexor hallucis longus tendon may coexist with os trigonum syndrome,
115
usually when the condition is chronic, as in ballet dancers; this leads to poorer outcome if surgical treatment is delayed [1, 7, 28]. When an open procedure is used, the surgical approach used to excise the ossicle is controversial. The posterolateral approach is easier and safer than the medial approach [7, 28]. The disadvantage of posterolateral approach is the relatively high number of sural nerve complications reported. Arthroscopy of the ankle is now a well-established procedure used for both accurate diagnosis and operative management of certain ankle disorders. Since Burman’s [29] first description in 1931, ankle arthroscopy has continued to present new challenges. Improvements in the technique and methods have expanded the indications for ankle arthroscopy. Many reports in the literatures dealing with lateral ankle ligament injuries and anterior ankle lesions are available. Pathologies of the posterior ankle are published comparatively rarely. Although anterior and posterior portals for ankle arthroscopy have been well documented [30, 33], the standard posteromedial portal has recognized risks because of the proximity of the posterior neurovascular structures [34, 35]. Several investigators have reported technical difficulties in addressing posterior ankle synovectomy [36, 37]. The posterolateral approach has been advocated by some authors in combination with routine anterior ankle arthroscopy [38, 39]; this makes systemic assessment of the posterior ankle joint possible but instrumentation from the front to the back of the joint is difficult. This also allows only intra-articular pathology to be assessed. Periarticular pathology, such as post-traumatic calcifications, periarticular scar tissue, symptomatic os trigonum, or FHL can not be assessed [20]. Frekel et al. [40] reported on a large consecutive series of 612 ankle arthroscopies; they recommended placement of the patient in the supine position and the use of antrolateral, anteromedial and posterolateral portals for routine procedures. They stated that anterocentral, transachillis, and posteromedial portals should never be used because of the potential neurovascular and tendon injury. Voto et al. [35] noted that the posteromedial portal is potentially hazardous even if placed adjacent to the achillis tendon, because of the location of neurovascular bundle. Recent anatomical and clinical studies have showed that the postero-medial portal for ankle arthroscopy is safe as well as the well established postero-lateral portal. Finally, Parisien et al. [37], in cadaveric study, noted that posterior lesions and loose bodies within the posterior pouch where seen better and were treated more effectively through two posterior portals when the limb was in the prone position.
FussSprungg 2
2006
116
M. E. M. Fadel and J. Jerosch
Feiwell and Frey [34] showed the posteromedial portal to be an average 7.5 mm from posterior tibial nerve with actual contact in some cases and also reported that the average distance between the posterolateral portal and the sural nerve was 6.0 mm. Acevedo et al. [41], in a cadaveric anatomic study, described a new coaxial procedure with two posterior portals for ankle arthroscopy with no cases of penetration or contact of any of the posterior neurovascular structures, neither medially nor laterally. Van Dijk et al. [20] reported 86 consecutive endoscopic hindfoot procedures through 2 posterior portals without any complications. Abramowitz et al. [28], demonstrated in his study on 41 patients undergoing open os trigonum resection, that the clinical outcome is similar between open and arthroscopic approaches, whereby the advantage of arthroscopy is early ambulation and healing and more patient satisfaction. In open techniques, the time to full recovery averaged five months and ranged from one to twelve months [7, 23, 28]. Van Dijk et al. [20] described only one case of arthrscopic treatment of os trigonum with excellent results. The average postoperative AOFAS score for eleven patients treated with arthroscopic excision in
the clinical series reported by Marumoto and Ferkel [21] was 86.4 points. In this study we used the two posterior portals of the ankle (posteromedial and posterolateral) to perform complete resection of symptomatic os trigonum in two young females in competitive sports. Both patients were pain-free within 2 weeks post-operation. They resumed their professional sport activities after a period of 4 weeks. There were neither complications nor recurrent symptoms recorded.
Conclusion We concluded that arthroscopic removal of symptomatic os trigonum through two posterior portals is an effective and safe treatment and facilitates early rehabilitation. It also allows dynamic tests and assessment of intra-articular pathology. We also believe that a high level of suspicion and early diagnosis and treatment os trigonum syndrome are important not only to relieve current pain but also to improve the prognosis. More prospective studies on a larger number of patients is needed.
References 1. McDougall A (1955) The os trigonum. J Bone JointSurg Br 37:257–265 2. Mann RW, Owsley DW (1990) Os trigonum. Variation of a common accessory ossicle of the talus. J Am Podiatr Med Assoc 80:536–539 3. Grogan DP, Walling AK, Ogden JA (1990) Anatomy of the os trigonum. J Pediatr Orthop 10:618–622 4. Bizarro AH (1921) On sesamoid and supernumerary bones of the limbs. J Anat 55:256–268 5. Quirk R (1994) Commom foot and ankle injuries in dance. Orthop clin north am 25:123–133 6. Burman MS, Lapidus PW (1931) The functional disturbances caused by the inconstant bones and sesamoids of the foot. Arch Surg 22:936–975 7. Brodsky AE, Khalil MA (1986) Talar compression syndrome. Am J Sports Med 14:472–476 8. Sarrafian SK (1983) Anatomy of the foot and ankle: descriptive, topographic, functional. Lippincott, Philadelphia, pp 18, 52-3, 94 9. Lapidus PW (1972) A note on fracture of the os trigonm syndrome. Bull Hosp Joint Dis 33:150–154
FussSprungg 2
2006
10. Stieda L (1869) Über secondäre Fußwurzelknochen. Arch phsiol WissenechMed 108:111 11. Turner W (1882) A secondary astragalus in the human foot. J Anat Physiol 17:82–83 12. Shepherd FJ (1882) A hitherto undescribed fracture of the astragalus. J Anat Physiol 17:79–81 13. Bureauf NJ, Cardinal E, Hobden R, Aubin B (2000) Posterior ankle impingement syndrome: MR imaging findings in seven patient. Radiology 215(2):497–503 14. Blake RL, Lxllas RJ, Ferguson H (1992) The os trigonum syndrome: a literature review. J Am Podiatr Med Assoc 82:154–161 15. Hedrick MR, McBryde AM (1994) Posterior ankle impingement. Foot Ankle Int 15:2–8 16. Martin BF (1989) Posterior triangle pain: the os trigonum. J Foot Surg 28:312–318 17. Howse AJ (1982) Posterior block of the ankle joint in dancers. Foot Ankle 3:81–84 18. Feiwell LA, Frey C (1993) Anatomic study of arthroscopic portal sites of the ankle. Foot Ankle 14:142–147
19. Ferkel RD, Fasulo GJ (1994) Arthroscopic treatment of ankle injuries. Orthop Clin North Am 25:17–32 20. Van Dijk CN, Scholten PE, Krips R (2000) A 2-portal endoscopic approach for diagnosis and treatment of posterior ankle pathology. Arthroscopy 16:871–876 21. Marumoto JM, Ferkel RD (1997) Arthroscopic excision of the os trigonum: A new technique with preliminary clinical results. Foot Ankle 18:777–784 22. Lohrer H, Arentz S (2004) Posterior approach for arthroscopic treatment of posterolateral impingement syndrome of the ankle in a top-level field hockey player, A case report. Arthroscopy 20:e15–e21 23. Hamilton WG, Geppert MJ, Thompson FM (1996) Posterior aspect of the ankle in dancers: differential diagnosis and operative treatment. J Bone Joint Surg Am 78:1491–1500 24. Marotta JJ, Micheli LJ (1992) Os trigonum impingement in dancers. Am J Sports Med 20:533–536 25. Karasick D, Schweitzer ME (1996) The os thgonum syndrome: imaging features. Am Roenrgenol l66:125–129
Arthroscopic resection of symptomatic ”os trigonum“
26. Wakeley CJ, Johnson DP, Watt I (1996) The value of MR imaging in the diagnosis of the os trigonum syndrome. Skeletal Radiol 25:133–136 27. Johnson RP, Collier D, Carrera GF (1984) The os trigonum syndrome: use of bone scan in the diaqosis. J Trauma 24:761–764 28. Abramowitz Y, Wollstein R, Barazilay Y, London E, Matan Y, Shabat S, Nyska M, MD (2003) Outcome of the resection of a symptomatic os trigonum. J Bone Joint Surg Am 85:1051– 1057 29. Burman MS (1985) Arthroscopy of direct visualization of joints: An experimental cadaveric study. J Bone Joint Surg 13:669 30. Andrews JR, Previte WJ, Carson WG (1985) Arthroscopy of the ankle: Technique and normal anatomy. Foot Ankle 6:29–33 31. Drez D, Guhl JF, Gollehon DL (1981) Ankle arthroscopy: Techniques and indications. Foot Ankle 2:138–143
117
32. Guhl JF (1986) New techniques for arthroscopic surgery of the ankle: Preliminary report. Orthopedics 9: 261–269 33. Parisien JS, Vangsness T (1985) Operative arthroscopy of the ankle: Three years’ experience. Clin Orthop 199:46–53 34. Feiwell LA, Frey C (1993) Anatomic study of arthroscopic portal sites of the ankle. Foot Ankle 14:142–147 35. Voto SJ, Ewing JW, Fleissner PR (1989) Ankle arthroscopy: Neurovascular and arthroscopic anatomy of standard and trans-Achilles tendon portal placement. Arthroscopy 5:41– 46 36. Ferkel RD (1993) Arthroscopy of the ankle and foot. In: Mann RA, Coghlin MJ (eds) Surgery of the foot and ankle. Vol 2, Ed 6. Mosby, St. Louis, pp 1277–1310
37. Parisien JS, Vangsness T, Feldman R (1987) Diagnostic and operative arthroscopy of the ankle: An experimental approach. Clin Orthop 224:228–236 38. Ferkel RD, Fischer SP (1989) Progress in ankle anhroscopy. Clin Orthop Res 240:210–220 39. Ferkel RD, Scranton PE Jr (1993) Athroscopy of dIe ankle and foot. J Bone Joint Surg Am 75:1233–1242 40. Ferkel RD, Heath DD, Guhl JF (1996) Neurological complications of ankle arthroscopy. Arthroscopy 12:200–208 41. Acevedo JI, Busch MT, Ganey TM, Hutton WC, Ogden JA (2000) Coaxial portals for posterior ankle arthroscopy: an anatomic study with clinical correlation on 29 patients. Arthroscopy 16:836–842
FussSprungg 2
2006