Ankle Fractures

Introduction

Ankle fractures refer to fractures of the malleoli. Although pilon and talar body fractures are included in the ankle joint anatomically, they are considered distinct injuries in their own right and will be discussed elsewehere.

 

Epidemiology

The incidence of ankle fractures is ~180 fractures per 100,000 people in the population per year. They are the second most common fracture in adults (9%) after femoral neck fractures. They have a bimodal age distribution with peaks in younger males and older females.

Isolated distal fibular or lateral malleolus fractures occur in two thirds of patients, bimalleolar fractures occur in a quarter and trimalleolar fractures in the remaining 7%.

 

Presentation

  • Low-energy fall (38%-80%)
  • Inversion injuries (31%)
  • Sporting injuries (10%)
  • Fall from stairs (8%)
  • Fall from a height (4%)
  • Motor vehicle accident (4%)

Patients typically present after an injury (although note neuropathic patients including diabetics may not recall one due if they are insensate) with pain, swelling and deformity. Subluxed or dislocated ankles will classically have the foot in a more anterior or externally rotated position than normal with tenting of the bone on the skin.

 

Classification

Danis-Weber Classification

A - Fracture below the syndesmosis

B - Fracture at the level of the syndesmosis

C - Fracture above the syndesmosis

Lauge-Hansen Classification

​This is based on (1) the position of the foot at the time of injury and; (2) the deforming force on the ankle.

Supination-adduction – (SA; 2 stages)

Transverse fracture of the lateral malleolus inferior to the ankle joint (SA1) with classically vertical shear fracture of the medial malleolus (SA2).

Supination-external rotation (SER; 4 stages)

Most common ankle fracture occuring at the level of the syndesmosis. The SER2 has no medial injury, is mechanically stable and do not require surgery. The SER4 fracture has a medial component: either a medial malleolar fracture or a deltoid rupture, and may require surgery depending upon on reduction in a weight bearing position.

Pronation-external rotation (PER; 4 stages)

Fracture is proximal to the syndesmosis and may be as high as fibular neck (Maisonneuve) with associated syndesmotic injury.

Pronation-abduction (PA; 3 stages)

Fracture is either at the level of above the level of the syndesmosis. It can be distinguised from the SER or PER patterns through the display of of comminuted fracture of fibula which occurs with a bending force that spits out a butterfly fragment. 

 

​Management

Patients should be treated according to BOA standards for trauma (BOAST).

Plain radiographs will give the diagnosis in most cases although CT may be useful in understanding complex fracture patterns to map out fracture anatomy and for surgical planning.

​Management of ankle fractures depends on accurate determination of the nature and severity of the injury. The choice of conservative or surgical management depends on the patient and whether the fracture is ‘stable’ or ‘unstable’.

Non-operative management

​Non-operative management includes immobilisation with plaster cast or boot, either weight-bearing or non-weight-bearing, for 6 weeks or functional management with controlled range of motion and combinations of non-weightbearing or weight-bearing may also be considered.

Hutchinson and Barrie suggested that the majority of ankle fractures seen in clinic are stable, are not likely to displace and do not require plaster casting to achieve union in a good position. They reviewed 163 patients with stable ankle fractures over a period of 8 years. Patients were offered a choice of a weight bearing below knee cast; a functional ankle brace; or a regime of rest, ice, compression bandage and elevation. This requires a detailed discussion with the patients and a shared decision-making.

In potentially unstable fractures treated non-operatively with cast application, it may be necessary to follow the patient weekly with serial x-rays to assess the position of the fracture, with cast removal at approximately 6 weeks depending on clinical and radiographic evidence of healing.

Non-operative treatment of unstable ankle fractures is associated with a non-union rate of between 48 and 73% compared to 0 and 19% after operative treatment. Non-operative treatment is also associated with an increased risk of loss of reduction and subsequent posttraumatic arthritis.

Non-operative vs. Operative Treatment

Some studies have directly compared the outcome of conservative and surgical treatment, however it is difficult to establish a sound conclusion due to flaws in study designs, smaller number of patients and variation in fracture patterns.

A systematic review of literature by Donken et al. showed there was insufficient evidence to justify surgical management of type B ankle fractures. This was because the prevailing RCTs identified by the review included patients with either different pattern of ankle fractures and/or with significant talar shift that potentially confounds the need for surgery.

​Long-term observational studies of ankle fractures also revealed good results for surgical or non-surgical management. Van Shcie-Can der Weert et al. conducted a retrospective study on 124 patients with type Weber B ankle fractures, 59% treated non-surgically and 41% were treated surgically and revealed good clinical outcomes in both groups.

Operative Treatment

Conventional approach for fixation of ankle fractures is increasingly viewed as an overly simplified as ‘one strategy fits all’ method, whilst ankle fractures vary in their morphology and stability.

Operative fixation techniques for ankle fractures are varied. Unstable or potentially unstable fractures are treated with ORIF. There are no guidelines for fixation devices.

Following the basic principles, good outcomes are expected if the talus is reduced and held anatomically within the mortise until the fracture heals. Anatomical reduction of fractures and restoring joint congruity are vital, as studies have shown that a 1mm lateral shift of the talus in the ankle mortise reduces the contact area of the ankle joint by 42% resulting in high contact stresses. The contact stress increases the most with shortening of the fibula, followed by lateral translation and followed by external rotation.

Simple lateral malleolar fractures are usually fixed with an interfragmentary lag screw and a neutralisation plate, or a posterior anti-glide plate, or a fibular intramedullary device. Comminuted fractures are fixed with a bridge plate technique.​

Vertical type medial malleolar fractures are fixed with a buttress plate technique (shearing fractures). Transverse medial malleolar fractures are usually fixed with 2 cancellous lag screws or tension band technique.

Timing of Surgery

Surgery should be performed as soon as reasonably possible and when soft tissues permit. A delay in operative treatment is associated with an increased rate of complications such as infection and lowered patient satisfaction as reported by some studies.

A systematic review reported 3.6% wound-related complications in patients treated within one week of sustaining the injury compared to 12.9% in patients treated after one week. This increase in complication rate has been shown to have a direct negative effect on functional outcomes.

Syndesmosis Stabilisation

Intraoperatively, the syndesmosis should be tested for stability and if unstable, an anatomical reduction and stable fixation with syndesmotic screws or tightropes is recommended.

Boden et al. and Yamaguchi et al. attempted to clarify the indications for syndesmosis fixation. They suggested that syndesmosis fixation is indicated only for a fibula fracture located at least 4.5 cm above the ankle joint in the presence of a deltoid ligament injury. This recommendation is based on two assumptions: first, that fixation of a medial malleolar fracture is equivalent to an intact deltoid, and second, that the interosseous membrane tear is limited to the level of the fibula fracture.

Satisfactory clinical outcome is associated with adequate reduction and stabilization of the syndesmosis. Controversies still surround regarding the size of screws (small vs large fragment), number of cortices engaged (3 vs 4), composition of implants (cortical vs cancellous, 1 vs 2 screws), position of the ankle joint during syndesmosis fixation, postoperative weight-bearing status, and the need for and timing of implant removal. Overall, there is no evidence that strongly supports one technique over the other, which may mean that each technique can be effective when applied properly.

Some recent studies have shown that the routine removal of syndesmotic screws has been associated with a high complication rate of over 20%, with both recurrent diastasis and wound infection following elective screw removal occurring in up to 10%.

New suture-button fixation devices (tightropes) are being used increasingly for stabilising syndesmotic injuries. These have been compared with screw fixation and shown that the use of tightropes leads to an earlier return to work, similar functional outcome (AOFAS score) and less frequent need for implant removal compared to screw. However, long-term follow-up data are lacking.

Locking vs. Non-Locking Plates

Biomechanical studies have advocated the use of locking plates for isolated distal fibula fractures in osteoporotic bone and comminuted fractures. These studies have shown that there were no statistically significant differences between the locking and conventional plate constructs during both fatigue and torque to failure testing. Hence in a normal bone and in the absence of fracture comminution, locking plates do not provide any mechanical advantage over one third tubular plates.

Plates vs. Fibular Nails

At present, there is insufficient evidence for changing practice from plating of unstable distal fibular fractures to intramedullary fixation based on the current literature, however, some studies have reported favourable results with nailing.

Advantages of locked intramedullary fibular nail include better rotational control, improved stability, less soft tissue disruption and reduced risk of nail migration. Initial reports were associated with higher rates of complications, however, with improved implants and techniques, their complications rates have reduced.

Rajeev et al. reported on a larger cohort of elderly patients treated with the fibular nails and all fractures healed uneventfully with no complications.

Bugler et al. reported radiological and functional outcomes of locked IM nails in a large series of patients with 6 years follow-up. Only half of their patients responded to the postal questionnaires regarding functional outcome, indicating a significant loss to follow-up. All fractures eventually united, and acceptable functional results were achieved through a variety of validated scoring systems. However, the overall complication rate was 22.8 %.

Tawari et al. reviewed two matched groups of patients who underwent fixation for unstable Weber B fractures with either IM nailing or standard AO plating. There was no significant difference between groups in time taken to achieve clinical and radiological union. One patient in the plate group had a wound infection, but there were no wound complications in the nailing group.

Bugler et al., in another study, presented the results of their prospective randomised controlled trial comparing locked IM nailing to plating. Whilst 16 % of patients in the plating group developed wound infections, no infections or wound complications occurred in the IM nailing group. At 1 year, functional outcome favoured the nailing group, but this difference was statistically insignificant. In addition, the overall cost of treatment in the nailing group was lower despite the increased cost of the implant.

Complications

Surgical treatment of ankle fractures may be accompanied by several complications including wound-related complications (most frequent), non-union, malunion, implant failure, venous thromboembolism, stiffness and degenerative joint disease.

Wound complications that may occur include wound edge necrosis, wound dehiscence, superficial infection, and deep infection.

Complications can be categorised in relation to the surgeon, the fracture, and the patient characteristics. The surgeon characteristics include the timing of surgery, placement of incision, soft tissue handling, type of implant being used and postoperative regime. The fracture characteristics include severity of the fracture and the surrounding soft tissue envelope. The patient characteristics include age, obesity, smoking, substance abuse, peripheral vascular disease and diabetes.

Post-traumatic arthritis has been described in 14% of patients despite an anatomic reduction, most likely as a result of chondral damage sustained at the time of initial injury. One arthroscopic study found 79% patients to have sustained some degree of chondral injury after ankle fractures.

A systematic review by Stufkens et al. showed that 79.3% of optimally reduced fractures have a good-to-excellent long-term outcome.

Rehabilitation

Controversies and debate exist as to the most effective postoperative protocol following ankle fracture fixation. Some authors suggest that early motion and weightbearing positively affect patient outcomes, while others maintain a more conservative approach with non-weightbearing and immobilization.

A systematic review reported that there was no significant difference at 1 year in ankle motion or functional outcomes when comparing postoperative immobilization and early range of motion. The review noted that early range of motion provided a quicker return to work; however, this was at the expense of an increased number of wound infections.

Another systematic review suggested that early range of motion and no immobilisation following surgery might provide a benefit to improved ankle range of motion, but at the expense of increased adverse events, which were mainly wound healing problems. It was also reported, based on limited evidence, that manual therapy was not beneficial for ankle range of motion following surgical fixation.

A multicentre randomised controlled trial compared early weight-bearing (after 2 weeks’ immobilization) with late weightbearing after operative fixation of unstable ankle fractures, including 110 patients. At 6 weeks postoperatively, patients in the early weightbearing group had significantly improved ankle range of motion (41 versus 29 degrees), ankle function scores and SF-36 scores. These differences diminished at final follow-up after 12 months. There were no differences with regard to wound complications and no cases of fixation failure or loss of reduction. Patients in the late weightbearing group had higher rates of planned/performed hardware removal due to plate irritation (19% versus 2%) at final follow-up after 12 months.

An RCT to determine the effectiveness of a supervised exercise programme and advice compared with advice alone after ankle fracture (both conservative and operative) showed similar outcome for the two groups. Therefore, a supervised exercise programme or physiotherapy is not routinely advised.

​

References

  • Court-Brown C, McQueen M, Tornetta P 3rd. Ankle fractures. in: Trauma, orthopaedic surgery essentials. Tornetta P 3rd, Einhorn T, eds. Philadelphia, PA; Lippincott Williams and Wilkins: 2006.

  • Weening B, Bhandari M. Predictors of functional outcome following transsyndesmotic screw fixation of ankle fractures. 2005;19:102-108.

  • Court-Brown CM, Caesar B. Epidemiology of adult fractures: a review. Injury 2006;37:691-7.

  • Ramsey PL, Hamilton W. Changes in tibiotalar area of contact caused by lateral talar shift. J Bone Joint Surg [Am] 1976;58-A:356-7.

  • Lloyd J, Elsayed S, Hariharan K, Tanaka H. Revisiting the concept of talar shift in ankle fractures. Foot Ankle Int 2006;27:793-6.

  • Thordarson DB, Motamed S, Hedman T, Ebramzadeh E, Bakshian S. The effect of fibular malreduction on contact pressures in an ankle fracture malunion model. J Bone Joint Surg [Am] 1997;79-A:1809-15.

  • Petrisor BA, Poolman R, Koval K, et al. Management of displaced ankle fractures. J Orthop Trauma.2006;20:515-518.

  • Schepers T, de Vries MR, van Lieshout EM, et al. The timing of ankle fracture surgery and the effect on infectious complications; a case series and systematic review of the literature. Int Orthop. 2013;37:489-494.

  • Hoiness P, Stromsoe K (2000) The influence of the timing of surgery on soft tissue complications and hospital stay. A review of 84 closed ankle fractures. Ann Chir Gynaecol 89:6–9.

  • Lynde MJ, Sautter T, Hamilton GA, Schuberth JM (2012) Complications after open reduction and internal fixation of ankle fractures in the elderly. Foot Ankle Surg 18:103–107.

  • Schepers T, Van Lieshout EMM, De Vries MR, Van der Elst M (2011) Increased rates of wound complications with locking plates in distal fibular fractures. Injury 42:1125–1129.

  • Tim Schepers & Mark R. De Vries & Esther M. M. Van Lieshout & Maarten Van der Elst; The timing of ankle fracture surgery and the effect on infectious complications; A case series and systematic review of the literature, International Orthopaedics (SICOT) (2013) 37:489–494.

  • Boden SD, Labropoulos PA,McCowin P, Lestini WF, Hurwitz SR: Mechanical considerations for the syndesmosis screw: A cadaver study. J Bone Joint Surg Am 1989;71:1548-1555.

  • Yamaguchi K, Martin CH, Boden SD, Labropoulos PA: Operative treatment of syndesmotic disruptions without use of a syndesmotic screw: A prospective clinical study. Foot Ankle Int 1994;15:407-414.

  • Hsu YT, Wu CC, Lee WC, Fan KF, Tseng IC, Lee PC (2011) Surgical treatment of syndesmotic diastasis: emphasis on effect of syndesmotic screw on ankle function. Int Orthop 35:359–364.

  • Tim Schepers; Acute distal tibiofibular syndesmosis injury: a systematic review of suture-button versus syndesmotic screw repair, International Orthopaedics (SICOT) (2012) 36:1199–1206.

  • Y. Asloum∗, B. Bedin , T. Roger , J.-L. Charissoux , J.-P. Arnaud , C. Mabit; Internal fixation of the fibula in ankle fractures. A prospective, randomized and comparative study: Plating versus nailing, Orthopaedics & Traumatology: Surgery & Research 100 (2014) S255–S259.

  • Annie Nguyentat, William Camisa , Sandeep Patel, Pieter Lagaay; A Biomechanical Comparison of Locking Versus Conventional Plate Fixation for Distal Fibula Fractures in Trimalleolar Ankle Injuries; The Journal of Foot and Ankle Surgery; Volume 55, Issue 1, January–February 2016, Pages 132-135.

  • Court-Brown CM, McBirnie J, Wilson G (1998) Adult ankle fractures–an increasing problem? Acta Orthop Scand 69(1):43–47.

  • Rajeev A, Senevirathna S, Radha S, Kashayap NS (2011) Functional outcomes after fibula locking nail for fragility fractures of the ankle. J Foot Ankle Surg 50(5):547–550.

  • Bugler KE, Watson CD, Hardie AR, Appleton P, McQueen MM, Court-Brown CM, White TO (2012) The treatment of unstable fractures of the ankle using the acumed fibular nail: development of a technique. J Bone Joint Surg Br 94(8):1107–1112.

  • Tawari G, Kakwani R, Shankar K (2012) Ankle fracture fixation plate osteosynthesis versus intramedullary fibular nail. Bone Joint J 94(B no. Supp XXXIX):239.

  • Donken Christian CMA, Al-Khateeb H, Verhofstad Michael HJ, van Laarhoven Cornelis JHM. Surgical versus conservative interventions for treating ankle fractures in adults. Cochrane Database Syst Rev.2012;8:CD008470.

  • Stufkens SAS, van den Bekerom MPJ, Kerkhoffs GMMJ, Hintermann B, van Dijk CN. Long-term outcome after 1822 operatively treated ankle fractures: a systematic review of the literature. Injury. 2011;42:119–27.

  • Van Schie-Van der Weert EM, Van Lieshout EMM, De Vries MR, Van der Elst M, Schepers T. Determinants of outcome in operatively and nonoperatively treated Weber-B ankle fractures. Arch Orthop Trauma Surg. 2012;132:257–63.

  • Mittal et al.; Type B ankle fractures: a retrospective study of longer‑term outcomes; BMC Res Notes (2017) 10:352.

  • Stufkens SA, van den Bekerom MP, Kerkhoffs GM, Hintermann B, van Dijk CN. Long-term outcome after 1822 operatively treated ankle fractures: a systematic review of the literature. Injury. 2011;42(2):119–27.