TARSOMETATARSAL ARTHRODESIS: TECHNIQUE AND RESULTS OF TREATMENT AFTER INJURY
April 5th, 1996
Mark S. Myerson, MD
Introduction
Although injuries to the tarsometatarsal joints are not very common, they are associated with substantial morbidity, sometimes regardless of initial treatment. I have identified these injuries in a variety of settings, associated with higher energy motor vehicle accidents, falls, and crushing of the foot, as well as more minor athletic twisting injuries.7,9,15 Regardless of the mechanism of injury, the treatment goal should always be to provide a stable and anatomic reduction, which has been identified with improved functional outcome.4-6,8,9,12,15,19
Over the past decade, the approach to treatment of injury to the tarsometatarsal joints has evolved, and reflects our increased understanding of the magnitude of forces involved. There has clearly been a trend toward operative treatment using more rigid forms of internal fixation. Although some of these injuries may be treated satisfactorily by conservative means, we now recognize that surgical treatment with closed reduction and percutaneous pin or screw fixation, or open reduction and internal fixation yields better results.2,4,7,12,14,15
Unfortunately, the incidence of painful arthrosis associated with these injuries has been reported to be quite high.1,5,7,12,19 Although most studies report an increased morbidity associated with nonanatomic forms of treatment, this arthrosis may occur despite appropriate reduction and rehabilitation to maximize function. Unfortunately, the true extent of the injury is often not appreciated, and often the more subtle forms of this injury are misdiagnosed. Perhaps far greater injury to the articular surfaces occur when dislocation is masked by partial spontaneous relocation.
The Anatomy and Physiology of Injury and Subsequent Deformity
It is important to understand the structure and function of the tarsometatarsal joint complex to provide treatment for the acute injury as well as the subsequent deformity. Most now recognize the important role of the second metatarsal base in the diagnosis and subsequent treatment. Structural rigidity of this complex articulation is provided by the dove-tailing of the second metatarsal base. With the exception of the second, the metatarsals are connected at their bases by strong interosseous ligaments, located slightly toward the plantar surfaces. There is no ligament between the first and second metatarsal, and a thick and extremely strong ligament extends from the medial base of the second metatarsal obliquely into the medial cuneiform. This ligament and the mortise effect created by the base of the second metatarsal are the main stabilizers of the entire tarsometatarsal articulation.
For practical purposes, the tarsometatarsal articulation consists of three separate parts or columns. This division has important practical implications for treatment, as recognition of the segmental patterns of injury and deformity that occur will aid in subsequent reduction of deformity. The medial column consists of the first metatarsal and the medial cuneiform; the middle column, of the second and third metatarsals and the middle and lateral cuneiforms; and the lateral column, of the fourth and fifth metatarsals and the cuboid. This columnar division is based on the relative movements of each, since they vary significantly. The fourth and fifth metatarsals move more in both the sagittal and horizontal planes than does the third metatarsal. The second metatarsal is held rigidly in the mortise and moves minimally, whereas the first metatarsal is again more mobile. 13,16 Despite the disparate movements of the three columns, as a functional unit the movement at the tarsometatarsal joint is that of pronation and supination.
Once dislocation of the tarsometatarsal joints occur, the secondary supportive structures, including the plantar fascia, intrinsic muscles, and tendons, are often secondarily involved and attenuated. Uniplanar dislocation of the tarsometatarsal joints seldom occurs, as other forces shift the metatarsals on the tarsus, causing abduction and lateral displacement as well as rotation. With indirect trauma, the forces produced are generally longitudinal and are applied to the foot with elements of torque, rotation, and compression. It is for this reason that associated deformity of the foot commonly occurs after an injury that is untreated or partially treated. The forefoot is abducted, the midfoot is pronated, and the medial column is shortened and dorsiflexed, and associated with hallux valgus deformity. A flatfoot deformity results with attenuation of the abductor hallucis and posterior tibial tendons and contracture of the peroneals, particularly the peroneus brevis tendon.
Patient Evaluation
Posttraumatic arthritis is a frustrating complication after tarsometatarsal injury. Other investigators and I have previously correlated the subsequent development of arthritis with inadequate or incorrect treatment of the initial injury. However, these are high-energy injuries, and if the articular surfaces are abraded or crushed during impact, arthritis may develop regardless of the apparent success of initial treatment even with anatomic reduction and appropriate fixation. Critics of more rigid methods of open reduction with screw fixation have suggested that arthritis may be the result of the trauma of screw fixation itself, but this is quite unlikely. Minimal motion occurs at these joints, and the joint with the least motion is the articulation most commonly involved with subsequent painful arthrosis. Conversely, the lateral column moves the most in both the sagittal and horizontal planes, but is the least likely to be involved in later symptomatic arthritis. Therefore, it is apparent that the rigidity of the middle column is the least forgiving, and the use of screws is unlikely to increase the potential for subsequent arthritis.
As noted above however, it is uncommon for symptomatic arthritis to develop if an anatomic reduction had been achieved and maintained. More likely, subtle deformity or incongruity still remains as the most likely precursor of arthritis. Each patient will present with a slightly different constellation of physical findings and complaints, depending on the extent of arthrosis, deformity, and soft-tissue compromise. Under normal circumstances, my colleagues and I offer most patients a trial of conservative, nonoperative care before recommending arthrodesis. However, there are some patients who present with more substantial deformity and symptomatology for whom delay in surgical salvage does not make sense.
When confronted with a patient who has sustained an injury to the tarsometatarsal joint complex, one must appreciate the initial mechanism of injury and the subsequent treatment, and attempt to localize the patient's symptoms carefully. For example, injury due to direct forces and crushing are quite different than those from indirect or twisting injury. In addition to the obvious consequences of fracture or dislocation, direct injury causes marked damage to the skin and other soft-tissue structures. When planning subsequent reconstruction, the potential for soft-tissue compromise and wound complications must therefore be recognized.
The extent of deformity and arthrosis does not correlate fully with symptoms, particularly since arthrosis of the lateral column is rarely symptomatic. I commence with a history of the injury and treatment, current symptoms, and activities of daily living (including work requirements and athletic interests). It is important to examine the patient while he or she is standing and walking, and to check the structure and function of the entire foot and ankle. The range of motion of the ankle, hindfoot, and forefoot is assessed, and the midfoot is stressed with a maneuver that involves passive pronation and simultaneous abduction of the forefoot. It is important to assess the areas of maximum tenderness, as well as the presence of neuritis, synovitis, and metatarsalgia. Pain under the second and third metatarsals may occur as a result of dorsal elevation of the medial column after injury or treatment, particularly if an acquired flatfoot deformity is present. As the forefoot abducts and the midfoot pronates in these patients, posterior tibial tendon insufficiency may occur with increasing deformity.
Decision-Making in Planning Treatment
Posttraumatic arthrosis may certainly be treated initially by conservative measures, including nonsteroidal antiinflammatory medications, molded insoles, rocker-bottom soles, and more rigid immobilization with a polypropylene ankle foot orthosis. If these methods fail to relieve the pain, arthrodesis of the tarsometatarsal joints has been recommended by various authors.5,7,19 I base the extent of the arthrodesis on the location of pain and the radiographic appearance of the foot. Weight-bearing anteroposterior, oblique, and lateral radiographs of both feet are obtained. The angle subtended between the talus and the first metatarsal and the height of the medial cuneiform from the floor on the lateral projection should be compared for each foot. On the anteroposterior and oblique views, the relationship between the middle and lateral columns are evaluated for lateral subluxation.
I typically use passive manipulation of the midfoot, which involves simultaneous pronation and abduction of the forefoot to determine which joints are symptomatic. I do not use local anesthetic injections to determine which joints are painful since these joints are small, and selective anesthesia into one or more joints is difficult and not sufficiently accurate. Although technetium bone scans may be useful to localize the involved joints, I have not found them to be particularly helpful since increased uptake is often present in joints which are not painful. This is particularly relevant with respect to the lateral column, where arthrodesis is rarely performed; yet, in these patients for whom a bone scan is obtained, increased uptake is often present. It has been my experience, therefore, that these additional diagnostic modalities are unnecessary to determine which joints are painful.
Operative Technique
General Principles
Two methods of arthrodesis are used, depending on the extent of deformity: in the presence of minimal deformity, an in-situ arthrodesis is performed with no attempt at realignment; when deformity is present, realignment in both the sagittal and transverse planes must be attempted before arthrodesis. One should also be prepared to perform additional procedures as required, including arthrodesis of the naviculocuneiform and calcaneocuboid joints for arthrosis, osteotomy of the calcaneus and tendon transfer for posterior tibial tendon insufficiency, neurectomy and nerve transposition for intractable dorsal neuritis, and clawtoe procedures for forefoot deformity.
The surgery may be performed under local ankle block anesthesia, depending on patient acceptance and the need for obtaining bone graft. Although bone graft is occasionally necessary, this may be harvested from the ipsilateral calcaneus and general anesthesia is therefore not necessary. The decision to use bone graft is based on the size of the defect created by debridement of the joints. Intraoperative radiographs are routinely obtained when any realignment of the forefoot is performed, and fluoroscopy is used routinely to determine the position of the internal fixation. When realignment is performed, radiographs should be obtained, since the fluoroscopic image does not give a sufficient two-dimensional picture of the entire foot.
Arthrodesis is performed using partially threaded cannulated screws. I currently use self-drilling, self-tapping cannulated screws (Orthopedic Biosystems, Phoenix, AZ), which I have found to be extremely useful for procedures about the midfoot and hindfoot (Fig. 1). These screws are designed with an odd facet on the head that has a low profile and is not prominent over the dorsum of the metatarsal or cuneiform. The screws are available in different sizes (2.7, 3.5, 4.3, 5.5, and 6.8 mm) that facilitate arthrodesis procedures about the midfoot.
In-situ Arthrodesis
This procedure is indicated for minimal deformity with arthritis limited to the medial and/or middle column, although more often limited to the middle column. I prefer to use local bone graft wherever possible; if any is required, local anesthesia is often sufficient. One incision, centered over the second tarsometatarsal joint, is used. If only the medial column is fused, the incision is dorsal to the shaft of the first metatarsal. The dorsocentral incision is made with care to identify and protect the superficial and deep peroneal nerves, dorsalis pedis artery, and the vertical descending arterial branch in the first web space. One should carefully identify the position of the second metatarsal, since the dorsocentral incision is often made too far medially, and this limits the visualization of the third metatarsocuneiform joint. I therefore always try to err slightly laterally toward the third metatarsal when planning this dorsal incision.
When exposing the space between the first and second metatarsals, one should avoid injury to the perforating branch of the dorsalis pedis artery. However, this is not always possible, particularly if the interspace requires debridement, and if so, the vessel should be ligated. The exposure of the neurovascular bundle is performed by subperiosteal dissection between the first and second metatarsals once the extensor hallucis brevis tendon is identified. This tendon lies immediately dorsal to the bundle and, once retracted, exposes the deeper tissues. The joints to be fused are exposed, the capsules are opened, and all fibrous tissue that blocks reduction is removed. Digital traction and plantar flexion of the distal metatarsals improves distraction of the joints. The cartilage and subchondral bone are then removed with a bevelled chisel. Excessive debridement of the joint should be avoided since doing so creates an unstable articulation that requires large amounts of bone graft to fill. It is important to remove the plantar aspect of the joint to prevent dorsal angulation and malunion. By inserting a lamina spreader into the dorsal joint space, the deeper plantar surface may be inspected and any remaining cartilage removed with a long thin rongeur.
Minimal reduction should be required with this in-situ technique. Once alignment is corrected after debridement, the position is temporarily secured with the cannulated guide pins, and radiographs are obtained. The screw size is selected according to the size of the metatarsal. In the tarsometatarsal joints, I typically use either 3.5- or 4.3-mm cannulated screws (Orthopedic Biosystems, Phoenix, AZ). To avoid splitting the dorsal cortex of the metatarsal, the cannulated countersink is used routinely, or the screw must be inserted from the cuneiform proximally into the metatarsal distally. A high-speed burr is then used to debride the joint edges and, if a gap is created, it is filled with local bone graft, which may be obtained from the calcaneus. Additional bone graft is usually unnecessary with these in-situ fusions (Fig. 2).
Realignment Arthrodesis
For patients who have residual displacement and deformity of the forefoot, realignment of the forefoot is preferable to an in-situ arthrodesis.17 The amount of displacement and angulation that requires realignment is not easy to quantify, although I typically use 2-mm displacement and 15o of angulatory malalignment to determine this step.15 This malalignment must be appreciated in both the transverse and sagittal planes since dorsal angulation of the medial column can be debilitating unless corrected. Some patients have a flatfoot deformity associated with forefoot abduction and lateral translation and dorsiflexion of the metatarsals. In these patients, the medial soft tissues including the abductor hallucis and posterior tibial tendon as well as the supportive ligaments are often attenuated and the lateral soft tissues are contracted.
The goal in reducing the deformity should be to restore alignment of the medial base of the first metatarsal with the medial edge of the cuneiform, restore alignment of the medial base of the second metatarsal with the medial edge of the middle cuneiform in the transverse plane, and align the long axis of the talus with the long axis of the first metatarsal in both the sagittal and transverse planes.3,17 The incisions are planned according to the deformity. For severe deformity, three incisions are used, one dorsomedial to the first metatarsal, one between the second and third metatarsals, and one dorsal to the fifth metatarsal, occasionally extending proximally to the calcaneus. If the lateral column is substantially displaced laterally or associated with severe forefoot abduction, the peroneus brevis tendon and other lateral soft tissues are contracted and require lengthening. If the peroneus brevis is noted to be restricting reduction, it may need to be lengthened, but this procedure should be performed only after mobilizing and releasing other joint scar and contracture laterally. To aid with this reduction of severe deformity, I use a small external fixation device intraoperatively. One pin is inserted laterally into the fifth and fourth metatarsals and a second pin is inserted into the calcaneus. The pins are inserted to converge slightly as an aid in the realignment. Before distraction is commenced, all joints are mobilized by resecting the scar tissue, debris, and cartilage since this will aid in the reduction, decreasing the distraction force laterally. A bevelled chisel is used to denude the joint surfaces, but no bone is resected since doing so would create large defects that would be difficult to correct.
The realignment is performed in a stepwise fashion, commencing medially with correction of the position of the first metatarsal. This is performed by grasping the hallux by the hand and forcing it into varus, while the base of the first metatarsal is pushed laterally with the thumb. In most cases, the first metatarsal is not only laterally but also dorsally displaced and angulated. This dorsal angulation is corrected by simultaneously dorsiflexing the hallux during the reduction maneuver, which depresses the first metatarsal head, improving realignment. The first metatarsal is temporarily secured with the cannulated guide pin(s). The second metatarsal is addressed next by placing a large bone reduction clamp obliquely between the base of the second metatarsal and the medial cuneiform to close the gap (Fig. 3). The middle column typically moves together, and the third metatarsal will follow with this reduction of the second. Both the second and the third metatarsals are secured with the cannulated guide pins, by first inserting a pin from the medial cuneiform distally toward the second metatarsal base. Anteroposterior and lateral radiographs are obtained to confirm the corrected alignment.
The lateral joints, which were also mobilized earlier by resection of scar tissue, are now realigned and secured either with Kirschner wires or screw fixation. However, this fixation of the lateral column is temporary and should be removed once weight-bearing is commenced at approximately 8 weeks after surgery. Arthrodesis of the lateral column is rarely required and should not be performed unless absolutely necessary. The arthrodesis is performed with 3.5- or 4.3-mm cannulated screws, determined by the size of the bones. The lateral column of the tarsometatarsal joint is only rarely included in the arthrodesis. It has been my experience that, despite substantial arthrofibrosis and deformity, these joints usually remain painless postoperatively, provided alignment is corrected.17 However, anatomic realignment is essential if displacement is greater than 2 mm.4,5,12,19 The wounds are closed with 4-0 subcuticular sutures and 5-0 chromic simple interrupted sutures used for the skin.
The patient is then placed in a bulky compression dressing, which is changed to a cast at 2 weeks. Weight-bearing is begun in a short leg walking cast or commercially available walking boot at approximately 8 weeks and may be used for an additional 4 to 8 weeks, depending on the healing of the arthrodesis as determined by the radiographs.
Complications of Treatment
Despite careful attention to surgical technique, complications do occur. Perhaps one of the more frustrating of these is neuritis of the deep or superficial peroneal nerves. These nerves are small, particularly the dorsal middle cutaneous branch of the superficial peroneal nerve. If one is not accustomed to exposure of the dorsum of the midfoot after trauma, then loupe magnification may be helpful with the initial dissection until the deeper tissue planes are reached and the nerve(s) can be retracted. Unfortunately, transection of the deep peroneal nerve may also occur due to scarring from previous surgery or to excessive dissection and retraction. This should not happen provided the entire soft-tissue mass is retracted, which is possible with careful subperiosteal dissection.
A postoperative neuroma must be treated promptly upon diagnosis since, if left untreated, it may be associated with the development of a severe and intractable neuritis or even reflex sympathetic dystrophy. I treat posttraumatic neuritis with various physical therapy modalities, including deep tissue massage, phonophoresis, and home use of a transcutaneous electrical nerve stimulator. If the nerve(s) are extremely irritated immediately after surgery, and if these physical therapies cannot be provided, my colleagues and I use a neuroleptic medication such as amitriptyline in low doses (10 to 25 mg) at night. If a neuroma is encountered or the nerve is cut intraoperatively, it is preferable to dissect the nerve more proximally and bury the nerve in deeper tissue or bone to prevent subsequent irritation.
Metatarsalgia may result from malunion of one or more metatarsals. This typically occurs as a result of incorrect or inadequate reduction of the first metatarsal, creating transfer of weight-bearing to the second metatarsal head. In most patients, this may be treated with forefoot padding, although metatarsal osteotomy of the involved metatarsal may be required.
Other complications of soft-tissue healing may occur, particularly if arthrodesis is performed after crush injury associated with any soft-tissue loss. In these patients, the potential for wound problems should be anticipated, and generous, long incisions should be made to minimize retraction on the wound edges. Fortunately, pseudoarthrosis is rare after tarsometatarsal arthrodesis. The metaphyseal bone of the bases of the metatarsals as well as the cuneiforms have broad bleeding cancellous bone surfaces. Only if excessive bone is resected is nonunion likely to occur. Although I have typically used bone graft to fill in any defects created by burring, this step may not be necessary, and is not used by all clinicians.
Discussion
I have presented my preferred approach to the diagnosis and surgical management of posttraumatic arthrosis of the tarsometatarsal joints. Other techniques for achieving arthrodesis have been reported, including the use of dowel bone grafts with no attempt at reduction of the deformity.10 The dowel graft method to obtain arthrodesis is not my preferred method to obtain arthrodesis because the removal of a dowel(s) creates additional instability of the metatarsocuneiform articulation and because this technique is not associated with an acceptable success rate, as originally reported.10
Many patients manifest radiographic evidence of arthritis of the lateral column joints but are painless in this location both pre- and postoperatively. Why this is the case is not well understood. Various authors have quantified the motion of the lateral column of the midfoot.13,16 Interestingly, the lateral column, which has the greatest sagittal plane motion (averaging 10o) is generally the least painful. However, the second metatarsocuneiform articulation, which has the least motion (average, 0.6o)16, is the most painful in most reported studies. In one series of 32 patients, only two required arthrodesis of the lateral column.11 Interestingly, both of these patients who underwent extended fusion of all three columns required subsequent revision surgery for metatarsalgia with metatarsal osteotomies. Although these numbers are small, one may infer that the motion of the lateral column is important for optimal function. Therefore, wherever possible, I recommend that the lateral column not be treated by arthrodesis, particularly since most of these joints are asymptomatic despite radiographic evidence of arthrosis.
Which columns require fusion? I have used clinical examination and plain radiographs to determine which joints require arthrodesis. Although I do not use nuclear imaging to help with this diagnosis, occasionally patients present for evaluation with one already performed, and in these patients, diffuse uptake throughout the midfoot is often present, often in locations that are painless. These scans are very sensitive to bone turnover or increased blood flow secondary to inflammation from arthritis, but they do not always coincide with the painful joints. Although the bone scan has been used by others, I do not recommend it nor do I resort to other imaging modalities to determine the extent of the arthrodesis.18
Realignment and arthrodesis is essential to achieve an optimal result. A correlation exists between the outcome and time between injury and fusion, alignment of the arthrodesis, quality of reduction, and whether the injury was work-related 17. My colleagues and I, as well as other investigators, have demonstrated that a significant factor in predicting outcome is the alignment of the arthrodesis.17
There is a high prevalence of posttraumatic arthritis after tarsometatarsal fractures and dislocations with or without adequate initial treatment, ranging from 0 to 58%.1,5-7,9,12,19 When conservative treatment fails to relieve these patients' symptoms to an acceptable level, arthrodesis of the painful tarsometatarsal joints is the treatment of choice.5,10,17
References
1. Aitken AP, Poulson D: Dislocations of the tarsometatarsal joint. J Bone Joint Surg 45A:246, 1963
2. Arntz CT, Veith RG, Hansen ST, Jr. Fractures and fracture-dislocations of the tarsometatarsal joint. J Bone Joint Surg 70A:173, 1988
3. Foster SC, Foster RR: Lisfranc's tarsometatarsal fracture-dislocation. Diagn Radiol 120:79, 1976
4. Geckeler EO: Dislocations and fracture-dislocations of the foot: transfixion with Kirschner wires. Surgery 25:730, 1949
5. Goossens M, De Stoop N: Lisfranc's fracture-dislocations: etiology, radiology, and results of treatment. A review of 20 cases. Clin Orthop 176:154, 1983
6. Granberry WM, Lipscomb PR: Dislocation of the tarsometatarsal joints. Surg Gynecol Obstet 114:467, 1962
7. Hardcastle PH, Reschauer R, Kutscha-Lissberg E, et al: Injuries to the tarsometatarsal joint. Incidence, classification and treatment. J Bone Joint Surg 64B:349, 1982
8. Hesp WLEM, van der Werken C, Goris RJA: Lisfranc dislocations: fractures and/or dislocations through the tarso-metatarsal joints. Injury 15:261, 1984
9. Jeffreys TE: LisFranc's fracture-dislocation. A clinical and experimental study of tarso-metatarsal dislocations and fracture-dislocations. J Bone Joint Surg 45B:546, 1963
10. Johnson JE, Johnson KA: Dowel arthrodesis for degenerative arthritis of the tarsometatarsal (Lisfranc) joints. Foot Ankle 6:243, 1986
11. Komenda GA, Myerson MS, Biddinger KR: Results of arthrodesis of the tarsometatarsal joints after trauma. J Bone Joint Surg in press:1996
12. Lenczner EM, Waddell JP, Graham JD: Tarsal-metatarsal (Lisfranc) dislocation. J Trauma 14:1012, 1974
13. Lundberg A, Svensson OK, Bylund C, et al: Kinematics of the foot/ankle complex -- Part 2: Pronation and supination. Foot Ankle 9:248, 1989
14. Myerson M: The diagnosis and treatment of injuries to the Lisfranc joint complex. Orthop Clin North Am 20:655, 1989
15. Myerson MS, Fisher RT, Burgess AR, et al: Fracture dislocations of the tarsometatarsal joints: end results correlated with pathology and treatment. Foot Ankle 6:225, 1986
16. Ouzounian TJ, Shereff MJ: In vitro determination of midfoot motion. Foot Ankle 10:140, 1989
17. Sangeorzan BJ, Veith RG, Hansen ST, Jr. Salvage of Lisfranc's tarsometatarsal joint by arthrodesis. Foot Ankle 10:193, 1990
18. Sobel MA, Mann RA: Tarsometatarsal arthrodesis for the treatment of primary degenerative arthritis of the midtarsal joints and delayed treatment of Lisfranc fracture/dislocations. Presented at the 61st Annual Meeting of the American Academy of Orthopaedic Surgeons, New Orleans (LA), February 25, 1994
19. Wilppula E: Tarsometatarsal fracture-dislocation. Late results in 26 patients. Acta Orthop Scand 44:335, 1973
Figure Legends
Fig. 1. This patient sustained a dislocation of the tarsometatarsal joints which was not initially treated. Note the abduction of the forefoot and the malalignment of the medial and middle column on the anteroposterior (A) and lateral (B) preoperative radiographs. The alignment was corrected and arthrodesis was accomplished with cannulated, self-drilling, self-tapping screws (C and D).
Fig. 2. An in situ arthrodesis was possible in this patient with traumatic arthritis of the medial and middle columns (A and B) treated with arthrodesis. Note that the screw heads were not prominent on the dorsal cortex of either the metatarsals or cuneiforms, visible on the postoperative views (C and D).
Fig. 3. The use of the bone reduction clamp applied to the base of the second metatarsal and the medial cuneiform is demonstrated.
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