Introduction

Fractures of the tibial shaft are the most common long bone fractures, with an incidence of more than 75,000 per year in the US [1]; most of these fractures are found in young males (thought to be related to sports or motor vehicle accidents) with a second peak of incidence among elderly patients, whose injuries likely resulted from a simple fall [2].  While intramedullary fixation has become the mainstay of treatment, many of these fractures are amenable to closed treatment.     

Structure and Function

The tibia carries nearly five times body weight of axial force during walking [3]. It is also subject to bending and twisting forces, especially when the foot is planted, though its resistance against these loads is far less than seen with compression.  The tibia is subcutaneous for much of its course, which subjects it to direct injury and may make healing more difficult. Likewise, the strong, noncompliant fascia around the muscles accompanying the tibia make the likelihood of a compartment syndrome greater than is seen with other long bone injuries. The anterior tibial artery, which gives rise to several periosteal vessels, is often damaged as it passes through a hiatus in the interosseus membrane; when the tibia fractures, this artery can be the source of substantial bleeding and elevated compartment pressure.

Diagnosis and Classification

Because the tibia is subcutaneous, the diagnosis of a fracture is usually patently obvious. Rather, the diagnostic task is to exclude an open fracture, an incipient compartment syndrome or an associated injury to the ligaments of the knee and ankle. Plain film radiography is often sufficient to demonstrate the injury and allow for its classification. 

Tibial shaft fractures are defined by their location within the bone (proximal, middle or distal third), the orientation of the fracture line (transverse, oblique, spiral or comminuted) Further mention is made regarding displacement and angulation.

The AO/OTA classification designates the region of the bone, a letter (A, B, C) for the severity of the fracture, and a number (1, 2, 3) indicating increasing complexity and comminution [4].  

Tscherne and Gotzen developed a classification system to evaluate soft tissue injury in closed tibial shaft fractures.  A type 0 injury usually results from an indirect, torsional force resulting in a simple fracture pattern and minimal soft tissue injury.  Type 1 represents mild to moderately severe fractures with superficial abrasions or contusions.  High energy fractures and deep abrasions with associated swelling comprise type 2 injuries, often with impending compartment syndrome.  Finally, type 3 injuries include extensive skin and muscle damage, often caused by a crush injury, a severe fracture pattern, and compartment syndrome [5].

Treatment

The goals of treatment are to promote bone healing;  to establish and maintain the normal length, alignment and rotation of the bone; to establish and maintain the normal anatomic  relationships between the knee and ankle joints for weight bearing, motion and propulsion; and to foster  pain-free, function of the lower limb. Whether these goals can be best met with surgery(intramedullary nailing, primarily) or with closed treatment (usually cast immobilization followed by functional bracing) depends on the particular circumstances of the injury; and even then, many such treatment recommendation are based on expert opinion and not studies with high levels of evidence.

According to experts [2], the non operative management may be employed when there is  minimal soft tissue injury and when the fracture is not displaced or deformed very much. The upper limits of tolerable  deformity are said to be:

  • 5 degrees of angulation in the coronal plane
  • 10 degrees of angulation in the sagittal plane
  • 5 degrees of rotational deformity
  • shortening of less than 1cm

If pursuing closed treatment, the patient should be placed in a long leg cast with the ankle in neutral and the knee positioned in 10-15 degrees of flextion to initiate early weight bearing.  A careful mold should be applied to the supracondylar area to prevent the cast from slipping.  Radiographs should be taken at 1-2 week intervals to verify maitenence of the reduction.  While some shortening from the initial reduction is to be expected, if greater than 1.5 cm of shortening is noted or the alignment criteria for closed management is no longer met, operative fixation is indicated [2].  As soon as the patient can comfortably bear weight, transition to a patellar bearing functional brace can be made. 

Interlocking reamed intramedullary nailing has become the standard for management of displaced tibial shaft fractures [7] (Figure 1).  For displaced tibial fractures, or those with significant soft tissue injuries, multiple studies [6,7] have demonstrated that intramedullary fixation results in quicker union, less malunion, and faster return to work than closed management.  

While the SPRINT study group recently reported that reamed IM nails resulted in a lower re-operation rate than unreamed nails in closed tibial shaft fractures [8], the debate over reaming is still on-going.  Reaming may disrupt the endosteal blood supply, theoretically, yet experimental studies have shown its re-establishment prior to healing and some clinical studies report better outcomes with reaming [9,10].   Reaming of course enlarges the canal and permits insertion of a larger nail, thus reducing the risk of fatigue failure of the implant.

If the fracture is transverse, the mechanical properties of the bone-implant construct allow for immediate weight bearing.

As a special consideration, fractures of the proximal third of the tibia shaft present a unique fixation challenge.  Malunion is an unfortunate consequence of nailing these fractures, occurring in 84% of patients in one case series [11], versus up to 37% of all closed tibial shaft fractures [12].  Careful selection of a starting point and the proper use of blocking screws can help prevent deformity [2,13].  

Because of the lack of soft tissue covering the tibia and mechanical disadvantage, internal fixation with plates is generally avoided.  Plating is a reasonable treatment option for management of tibial shaft nonunions or for fractures with articular or periarticular extension.  

External fixation may be chosen instead of intramedullary nails in patients with severe soft tissue injury or in the setting of damage control surgery in polytrauma [14].  If converting to an intramedullary nail, the procedure should be done as soon as possible, preferably with four weeks to minimize the likelihood of pin sepsis [15].  

Outcomes

The prognosis following tibial fracture depends on the extent of bone and soft tissue damage.  Most low energy closed tibial fractures achieve union by 10-13 weeks.  High energy fractures can often require as much as 20 weeks time to union [16].  

The expected union rates for  tibial diaphyseal fractures (in the absence of extensive soft tissue damage) is on the order of  95% or higher [17].  Even among  patients with high energy tibial fractures, 76% who were working at the time of injury eventually returned to work in an average of 11 months time [18].

Despite high general healing rates and good return to function, tibial shaft fractures still pose a surgical challenge. Complications of closed tibial shaft fractures include vascular injury, fat embolism, and compartment syndrome. Several studies have shown that the rate of compartment syndrome in AO Type A fractures is 5.8-15.6%, in Type B from 11.4-16.7%, and 9.6-28.6% in Type C fractures [19,20].  

Infection is a rare complication in closed fractures, with an incidence of less than 1% [21].  Intramedullary fixation is generally well tolerated, but can be complicated by nonunion, malunion, and implant failure [13].  Anterior knee pain is not uncommon after tibial nailing [22], an observation that should be conveyed to the patient early in treatment.  While the exact cause of knee pain is still unknown, it can present significant functional impairment.  In one study, 33.7% of patients reported pain at rest, 57% with running, and 92% with kneeling [22].

Pearls

  1. Tibial shaft fractures are associated with compartment syndrome. Consider admitting and observing all patients treated with cast immobilization, even if they appear comfortable enough for discharge from the Emergency Department.
  2. Classic cast immobilization of a long bone fracture involves the joint above and the joint below.  For tibia fractures, prolonged immobilization of the joint above and the joint below may impede knee and ankle function, even after the cast is removed. Consider converting to a patellar bearing functional brace as soon as possible.
  3. There are putative benefits to both reaming and not reaming –the debate remains unsettled even after the large-scale SPRINT trial.
  4. Many cases of delayed union ultimately go on to heal. Consider waiting at least 6 months before re-operating on a tibia fracture that has not healed.
  5. Small screws can be inserted into the tibia, adjacent to the canal, prior to the insertion of the intramedullary nail to guide the passage of the nail. These so-called “Blocking Screws” are especially useful in the prevention of malreduction of proximal tibial shaft fractures, where the metaphyseal canal is much wider than the nail itself.

References

  1. Praemer A, Furner S, Rice DP.  Musculoskeletal conditions in the United States.  Park Ridge, IL.  American Academy of Orthopaedic Surgeons; 1992.
  2. Schmidt AH, Finkemeier CG, Tornetta P.  Treatment of closed tibial fractures.  J Bone Joint Surg Am. 2003;85:352-68.
  3. Wehner T, Claes L, Simon U.  Internal loads in the human tibia during gait. Clin Biomech 2009; 24(3):299-302.
  4. Fracture and dislocation compendium. Orthopaedic Trauma Association Committee for Coding and Classification. J Orthop Trauma,1996;10 Suppl 1: 1-154.
  5. Tscherne H, Gotzen L, editors Fractures with soft tissue injuries. New York: Springer; 1984.
  6. Hooper GJ, Keddell RG, Penny ID.  Conservative management or closed nailing for tibial shaft fractures.  A randomised prospective trial.  J Bone Joint Surg Br.  1991;73:83-5.
  7. Bone LB, Sucato D, Stegemann PM, Rohrbacher BJ.  Displaced isolated fractures of the tibial shaft treated with either a cast or intramedullary nailing.  An outcome analysis of matched pairs of patients.  J Bone Joint Surg Am.  1997;79:1336-41.
  8. Bhandari M, Guyatt G, Tornetta P, et al. Randomized trial of reamed and unreamed intramedullary nailing of tibial shaft fractures. J Bone Joint Surg Am. 2008;90:2567-2578.
  9. Schemitsch EH, Kowalski MJ, Swiontkowski MF, Harrington RM, Senft D. Effects of reamed versus unreamed locked nailing on callus blood flow and early strength of union in a fractured sheep tibial model. Orthop Trans. 1995;18:145.
  10. Finkemeier CG, Schmidt AH, Kyle RF, Templeman DC, Varecka TF. A prospective, randomized study of intramedullary nails inserted with and without reaming for the treatment of open and closed fractures of the tibial shaft. J Orthop Trauma. 2000;14:187-193.
  11. Lang GJ, Cohen BE, Bosse MJ, Kellam JF.  Proximal third tibial shaft fractures,  Should they be nailed?  Clin Orthop.  1995;315:64-74.
  12. Williams J, Gibbons M, Trundle H, Murray D, Worlock P.  Complications of nailing in closed tibial fractures.  J Orthop Trauma.  1995;9:476-81.
  13. Cannada LK, Anglen JO, Archdeacon MT, Herscovici D Jr, Ostrum RF. Avoiding complications in the care of fractures of the tibia. J Bone Joint Surg Am. 2008;90:1760-8.
  14. Dall’oca C, Christodoulidis A, Bortolazzi R, Bartolozzi P, Lavini F. Treatment of 103 displaced tibial diaphyseal fractures with a radiolucent unilateral external fixator. Arch Orthop Trauma Surg. Apr 2 2010.
  15. Court-Brown CM, Keating JF, Christie J, McQueen MM. Exchange intramedullary nailing. Its use in aseptic tibial nonunion. J Bone Joint Surg Br. May 1995;77(3):407-11.
  16. Skoog A, Sodergvist A, Tornkvist H, Ponzer S.  One year outcome after tibial fractures.  Results of a prospective fracture registry. J Orthop Trauma. 2001;15:210-15.
  17. Sarmiento A, Sharpe FE, Ebramzadeh E, Normand P, Shankwiler J.  Factors influencing the outcome of closed tibial fractures treated with functional bracing.  Clin Orthop.  1995;315:8-24.
  18. Arangio GA, Lehr Shannon, Reed JF III. Reemployment of patients with surgical salvage of open, high-energy tibial fractures: an outcome study. J Trauma. 1997;42:942-945.
  19. Al-Dadah OQ, Darrah C, Cooper A, et al.  Continuous compartment pressure monitoring vs. clinical monitoring in tibial diaphyseal fractures. Injury.  2008;39:1204-1209.
  20. Park S, Ahn J, Gee AO, et al.  Compartment syndrome in tibial fractures.  J Orthop Trauma.  2006;23:514-518.
  21. Shuler FD, Obremskey WT.  Tibial shaft fractures.  In: Stannard JP, Schmidt AH, Kregor PJ, editors.  Surgical treatment of orthopaedic trauma.  New York: Thieme; 2007. p 742-66.
  22. Court-Brown CM, Gustilo T, Shaw AD. Knee pain after intramedullary tibial nailing: its incidence, etiology, and outcome. J Orthop Trauma. 1997;11:103-105.

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