By Al Kline DPM

 

The Jones fracture was first described by Sir Robert Jones in 1902 after sustaining the fracture during a Maypole dance.  It has also been called a dancers fracture.  The fracture is usually the result of stressed inversion and plantarflexion of the foot.  Sir Robert Jones treated his fracture conservatively, with good results.  However, over the years, there has been some controversy over when to treat the Jones fracture conservatively versus surgically.  There has also been some confusion over what consititutes a true ‘Jones’ fracture.  There are a number of reports in the literature sighting the high incidence of non-union in Jones fracture.  It is thought that the significant tendonous pull of the peroneus longus and brevis tendon accompanied by the inherent decreased vascularity to the styloid process can lead to a  high incidence of non-unions. High rates of non-union can also be due to improper determination for surgical intervention or when surgical intervention was not performed early enough.  Stress fractures have also been shown to progress to more involved cortical fractures that can also lead to non-unions or refracture.  Ortiguera and Fischer reported up to 50% non-union rate after 2 months of conservative casting in athletes treated for Jones fractures.  In a randomized study, Mologne et al reported a 44% failure rate including non-union, delayed union and refractures after conservative casting for Jones Fractures.   

When is conservative treatment preferred over surgical treatment and vice-versa?  It is the authors attempt in this article to introduce a simple classification for determination of conservative versus surgical treatment of a Jones fracture. 

 

Anatomy 

It is important to review the anatomy to the base of the fifth metatarsal.  The metatarsal is divided into the metatarsal head, distal metaphysis, central diaphysis and proximal body of the fifth metatarsal base and its most proximal styloid process or tuberosity.  Cadaveric studies by Theodorou et al showed how the anatomical attachments of the plantar aponeurosis and the peroneal tendons can influence fracture pathogensis at the tuberosity.  The entire styloid process and body of the base of the metatarsal is encompassed by broad fibrous bands formed by fibers converging from the lateral component of the plantar aponeurosis and  fibers of the peroneal brevis tendon. There are also ligamentous structures inserting into the proximal portion of the tuberosity. There is an anterior frenular ligament extending from the long peroneal tendon to the base of the fifth metatarsal.  This would suggest strong ligamentous and tendonous structures that can cause spontaneous avulsion of the styloid process or even body fractures to the fifth metatarsal base on stress.  Because of these stresses , it is the authors opinion that any fracture to the styloid process or base of the fifth metatarsal should be fixated or reduced surgically.  It is also my opinion that metatarsal stress fractures involving the fifth metatarsal distal to the body of the fifth metatarsal base, should also be repaired surgically. 

When we look closer at the base of the fifth metatarsal, the fracture region of the metatarsal  is divided into three distinct regions:  1)  the most proximal tuberosity or styloid process (T), 2) the body to the base of the fifth metatarsal  (B) and  3) the tubular surface just distal to the body of the base of the fifth metatarsal extending into the diaphysis (D).    

In reviewing the literature, these ‘zones’ differ and some are delineated by distance from the end of the bone.  For instance, fractures that are within 1.5 cm to the end of the styloid process is considered a ‘avulsion’ fracture.  Anything distal to that is a ‘metatarsal’ fracture. 

 

There has also been 3 zones of fracture descrbed in metatarsal base fractures:  1) zone of tuberosity fracture,  2) zone of Jones fracture and  3) zone of diaphyseal stress fracture. 

For our simplified classification, it is fractures that involve the styloid process that are considered true ‘avulsion’ fractures (T).  Fractures to the body of the fifth metatarsal base are considered ‘base fractures’ (B) and fractures distal to the body of the fifth metatarsal base  are considered ‘metatarsal’  or diaphyseal fractures (D).  In most of the literature, this is also the most common region for stress fractures associated with a Jones fracture. 

 

History of Classifications for Jones Fracture 

Historically, there are basically three types of proximal fifth metatarsal fractures 1) avulsion type, 2) fractures within 1.5cm of the tuberosity or styloid process or body fracture and 3) diaphyseal stress fractures.  A number of classifications have been sited over the years to differentiate the types of fractures to include 1) type of fracture and 2) whether the fifth metatarsal cuboid articulation is involved (intra-articular fracture).  One of the first classifications we learned in podiatry was the
I. M. Stewart Classification.  Stewart described a simple classification (Type 1A, 1B, 2A and 2B)  and a radiographic classification (Types 1-5).  Torg also described a classification (Type 1-3) outlining that conservative treatment is indicated for Type 1, conservative and sometimes surgical treatment for Type 2, and always surgical treatment for Type 3 fractures (nonunions that have intermedullar sclerosing). 

 

Torg Classification 

Type 1- No signs of intramedullary sclerosis, a sharp, well-delineated fracture line and minimal cortical hypertrophy.

Type 2- A fracture line that involves both cortices with associated periosteal new bone, a widened fracture line with adjacent radiolucency related to bone resorption and evidence of intramedullary sclerosis.

Type 3- A wide fracture line is seen with periosteal new bone and radiolucency, and complete obliteration of the medullary canal at the fracture site by sclerotic bone.

 

Stewart Classification 

Type 1A – A noncomminuted fracture at the junction of the metatarsal shaft and base.

Type 1B- A fracture at the junction of the shaft and base that is comminuted.

Type 2A –A fracture of the styloid process without articular involvement.

Type 2B – A fracture of the styoid process with articular involvement. 

I.M. Stewart also described a radiographic classification attempting to include not only fracture type, but its mechanism of injury. 

 

Stewarts Radiographic Classification 

Type 1- Fracture between the epiphysis and diaphysis, Supra-articular fracture caused by internal rotation of the forefoot while base of the fifth metatarsal remains fixed to the ground. 

Type 2-  Fractures that are intra-articular with one of more fracture lines.  This may include comminuted fractures with displacement of these fragments dependant on the extent of damage to the capsule and/or ligaments.  This is a fracture type usually caused by shearing forces and internal rotation of the forefoot while the peroneus brevis is contracted. 

Type 3- Epiphyseal fractures that are extra-articular.  The fracture lines are usually at right angles with the long axis of the fifth metatarsal.  This fracture is cause by a sudden, sharp contracture of the peroneal brevis tendon. 

Type 4-  Traumatic, comminuted fracture to the base of the fifth metatarsal.  Mechanism of injury is a crushing force between the cuboid and the ground or shoe caused by direct or indirect trauma.

Type 5-  Fractures of children.  A partial avulsion fracture of the epiphysis with or without fracture line or hir line as in type 2 fractures.  

 

Introduction of Simplified Classification 

Fractures to the base of the fifth metatarsal has been classified as acute fractures and chronic fractures.  Acute fractures is associated with acute injury such as twisting or inverting or plantarflexing the foot.  This can occur from accidents such as stepping in holes, running, falls and in sports for example.  Chronic injuries usually occur in sports such as running.  These injuries manifest themselves as stress fractures associated with prodromal pain.  The premise to introduce a new classification is based on the high incidence of nonunion and refracture, even in the presence of early stress fractures.  Simple stress fractures of the fifth proximal metatarsal can lead to more progressive fracture of the fifth metatarsal base if under treated.  This is likely due to the dynamic forces that travel through the fifth metatarsal base that makes it unique amoung the other metatarsals.  These fractures have been surgically treated with percutaneous intermedullary screws in athletes.  They have reported that earlier intervention will allow athletes to return to pre-injury status earlier.  Of course, without proper treatment, there is a high incidence of non-unions and residual swelling and pain that is reported from patients long after they sustained a Jones fracture. 

 

The Simple Classification  

Stage 1:  No signs of fracture, but pain following acute or chronic injury to the structures attached to the base of the fifth metatarsal and is symptomatic. 

Treatment:  Conservative casting for 6 weeks with complete non-weight bearing. 

Stage 2:  Stress fracture to any part of the base of the fifth metatarsal including diaphysis, body and/or tuberosity. 

Treatment:  Open reduction and internal fixation using percutaneous intermedullary screw to prevent overt fractures and promote stability and quicker recovery.    

Stage 3:  Overt fractures that involves the body to the base of the fifth metatarsal, styloid process, intra or extra articular, either one or two cortices, regardless of symptomatology.

Treatment:  All of these fractures should be fixated though standard ORIF techniques including pinning, plating and solitary dynamic compression or tension banding.  

Radiographs highlighting early stress fracture that can progress to overt fracture.  Here, is an example of intermedullary screw fixation as described by Cedric J. Ortiguera, MD and David A. Fischer, MD (Ortiguera, C, et al:  A Review of the Current Treatment for Fracture of the Proximal Fifth Metatarsal as First Described by Jones  Orthopedic Technology Review 2 (4), 2000)

 

Discussion 

Patient symptomatology and radiographic/MRI findings play an important role in the decision to perform surgery.  For instance, a patient that presents with localized pain to the proximal fifth metatarsal, but no avulsion fracture or stress fracture to the fifth metatarsal either after acute or chronic injury, will likely respond very well to conservative bracing and casting.  If a stress fracture is suspected and not obviously seen on radiograph , a differential of peroneal tendonitis versus actual stress fracture should be ruled out.  The MRI could be ordered to get a more definitive diagnosis in that case.  It must be said, however, that under-treatment of this condition may lead to fracture and avulsion due to the weight bearing forces exerted through the base of the fifth metatrasal on gait.  In the stage 2, if the stress fracture is seen on radiograph or MRI and is  painful, intermedullary screw compression is indicated.  Conservative casting could be attempted, however there is a probability of non or delayed union if in the area of the styloid or body of the fifth metatarsal base.  Refracture or more pronounced fracture may also result.  In the stage 3 fracture, all attempts at surgical correction should be attempted initially without the need for conservative casting.  An attempt at casting a styloid fracture that encompasses either one or two cortices, will likely lead to non-union and improper healing of the fracture.  Early surgical intervention using standard ORIF techniques is recommended.  Once the fracture is fixated, proper non-weight bearing in a posterior splint for 2 weeks and a short leg cast for 4 to 6 weeks is the authors recommendation. 

 

Conclusion: 

The Jones fracture is a common fracture seen through the office or emergency room.  Lack of early intervention and improper treatment of this fracture has led to a high incidence of delayed unions, non-unions and refractures.   A simple classification system is introduced which stresses the need for earlier surgical intervention in stress related and more overt fractures to the base of the fifth metatarsal.  Earlier recognition of stress related injuries and appropriate intervention will lead to a more rapid recovery. 

 

 

References: Mologne, TS:  Early Screw Fixation Versus casting in the Treatment of Acute Jones Fractures.  The American Journal of Sports Medicine 33:970-975. 2005 

Ortiguera, C, et al:  A Review of the Current Treatment for Fracture of the Proximal Fifth Metatarsal as First Described by Jones  Orthopedic Technology Review 2 (4), 2000 Strayer, S. et al:  Fractures of the Proximal Fifth Metatarsal American Family Physician 59: 9 , 1999. 

Jones, R.  Fractures of the Fifth Metatarsal Bone,
Liverpool med. Surg. J.  42: 103-107,1902
 Jones, R.  Fracture of the Base of the Fifth Metatarsal Bone by Indirect Violence, Ann. Surg. 35: 697-700, 1902 

Stewart, I.M.  Jone’s Fracture:  Fracture of Base of Fifth Metatarsal  Clini. Orthop. 16:190-198, 1960 Dameron, T.B.  Fracture and Anatomical Variations of the Proximal Portion of the Fifth Metatarsal JBJS 57A: 788-792, 1975. 

Kavanaugh, J.H., et al.  The Jones Fracture Revisited  JBJS 60A:  776-782, 1978 Pearson, J.B.  Fractures of the Base of the Fifth Metatarsal  Br. Med J.  1:  1052-1054, 1962 

Peltier, L.F.  Eponymic Fractures:  Robert Jones and Jone’s Fracture, Surgery 71:  522-526, 1972. Stone, M.M.  Avulsion Fracture of the base of the Fifth metatarsal, Am.J. Orthop. Surg.  10:  190-193, 1968. 

Torg, J.S., et al  Fracture of the Base of the Fifth Metatarsal Distal to the Tuberosity: Classification and Guidelines for Nonsurgical and Surgical management.  JBJS 66A: 209-214, 1984. Zelko, R.R. et al  Proximal Diaphyseal Fracture of the Fifth Metatarsal:  Treatment of the Fractures and their Complications in Athletes.  Am. J. Sports. Med.  7:  95-101,  1979. 

Pritsch, M., et al An Unusual Fracture of the Base of the Fifth Metatarsal Bone  J. Trauma 20:  530-531, 1980 Soufflet, M.  Fracture of the Base of the 5th Metatarsal (Jone’s Fracture)  Radiologic Classification (After I.M. Stewart)  translated from Courrier des Pedicures Romands, Chiropodist, April 1983.   

Lehman RC, et al Fractures of the base of the fifth metatarsal distal to the tuberosity: a review. Foot Ankle 1987;7:245-52.  Torg JS. Fractures of the base of the fifth metatarsal distal to the tuberosity. Orthopedics 1990;13:731-7.  

Parkinson, D.E. et al Biomechanical Principals of Tension Band Wiring Applied to Fractures of the Distal Fibular and Fifth Metatarsal Base JFS 27(2) :  149-156, 1988.   Lee, P. et al:  Musculoskelatal Collloquialisms:  How Did We Come Up with These Names?  Radiographics 24: 1009-1027, 2004 Theodorou, D.J. et al:  Fractures of Proximal Portion of Fifth Metatarsal Bone: Anatomic and Imaging Evidence of a Pathogenesis of Avulsion of the Plantar Aponeurosis and the Short Peroneal Muscle Tendon.  Radiology (http://radiology.rsnajnls.org/cgi/content/figsonly/226/3/857). 

© Al Kline DPM, 2006