F Arnaout undertakes a systematic literature review
Abstract
Tibial plateau fractures are common injuries for which a unified approach to treatment and outcome assessment remains elusive. There have been concerns that the associated soft tissue injury may lead to wound complications after internal fixation. These concerns have led to the increased use of external fixation for complex fractures of the tibial plateau.
A systematic literature review of papers comparing these two techniques was performed. The Medline database was searched and the terms associated with tibial plateau fractures were inserted.
Twenty-three studies were retrieved but only three papers were comparative. The first study is a multi-centre RCT, the second one is a biomechanical study and the third one is case series.
External fixation has some advantages in terms of the soft tissues healing, but it has not demonstrated improved outcomes over internal fixation.
Introduction
Problem: A bicondylar tibial plateau fracture is defined as a fracture of both medial and lateral proximal tibial condyles involving the central articular surface, which supports the opposing femoral condyles.2
Tibial plateau fractures are often the result of blunt trauma and are associated with severe soft-tissue injury. Fixation techniques demand considerable surgical skills and mature judgment. The available surgical options do not always guarantee a favorable outcome.
Operative treatment includes internal and external fixation, hybrid fixation and arthroscopically assisted techniques. Operative management of high-energy fractures remains difficult and challenging and may be associated with serious complications: knee stiffness, ankylosis, deep infection, post-traumatic arthritis, mal-union and non-union. Prevention of the complications can optimise the clinical outcome in these patients.4
Incidence: Tibial plateau fracture is a common injury with an incidence of approximately 1% of all fracture and 9.2% of all tibial fractures. As an intra-articular fracture, it involves the medial or lateral or both tibial condyles. Bicondylar tibial plateau fractures are difficult to treat with a complication rate that varies from 20% to 70%.8
Current treatments: A non-operative approach with a hinged knee brace is indicated for minimally displaced fractures and in medically unfit or non-ambulatory patients. Current internal fixation techniques using open reduction, bone graft and plating techniques often with a locking plate provide the basis for internal fixation of these injuries.
New treatments: Standard open reduction and internal fixation techniques have been successful in restoring osseous alignment for bicondylar tibial plateau fractures. However, surgical morbidity, especially soft-tissue infection and wound necrosis, has been frequently reported. When extensive comminution and damaged soft tissues prohibit their use, external fixators provide an excellent fallback option for their management. For this reason, several investigators have proposed minimally invasive methods of fracture reduction followed by circular external fixation as an alternative approach.
Consequences: The results of treatment are dependent on the amount of intra-articular comminution, the presence or absence of a step deformity on the weight-bearing surface, and residual angulation deformity. Inappropriately treated fractures could lead to soft tissue infection, necrosis, and knee stiffness.6
Results
The first study for discussion is ‘Open Reduction and Internal Fixation Compared with Circular Fixator for Bicondylar Tibial Plateau Fractures’ by the Canadian Orthopaedic Trauma Society (COTS).
The authors performed an interventional multi-centre, prospective, randomised clinical trial in which standard open reduction and internal fixation with medial and lateral plates was compared with percutaneous and/or limited open fixation and application of a circular fixator for displaced bicondylar tibial plateau fractures. This is a very important clinical research question, to our knowledge the only RCT addressing it.
The null hypothesis was that there is no difference between circular external fixation and open reduction and internal fixation. The eligible population was patients with bicondylar tibial fractures of Schatzker types V and VI and Orthopaedic Trauma Association types C1, C2, and C3. Eighty-three fractures were randomised to operative treatment (forty-three fractures were randomised to circular external fixation and forty to open reduction and internal fixation).
The method of randomisation was carried out in the gold standard manner using sequentially numbered opaque sealed envelopes. Therefore we can exclude selection bias from this study.
Follow-up consisted of obtaining a history, physical examination, and radiographs; completion of the Hospital for Special Surgery (HSS) knee score, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Short Form-36 (SF-36) General Health Survey; as well as recording the complications and re-operation rates.
These outcome measures were validated and reproducible. The authors identified HSS as a primary outcome measure to decide on the difference between the two treatments. Sixteen different surgeons were involved which allows for external validity of their results.
The two groups were controlled adequately; and as a result, there were no significant differences between the groups in terms of demographic variables, mechanism of injury, or fracture severity and/or displacement. Type I error was reduced. A large number of fractures (83) were included, but a power calculation was not performed to determine if this sample size was adequate to show a significant difference. In addition, the statistical methods used to analyse data were not given.
The results showed no significant differences between the groups in terms of demographic variables, mechanism of injury, or fracture severity and/or displacement. However, patients in the circular fixator group had less intraoperative blood loss than those in the open reduction and internal fixation group (p = 0.006), and spent less time in the hospital (p = 0.024).
The quality of osseous reduction was similar in the groups. There was a trend for patients in the circular fixator group to have superior early outcomes in terms of HSS scores at six months (p = 0.064), and the ability to return to pre-injury activities at six months (p = 0.031) and twelve months (p = 0.024).
These outcomes were not significantly different at two years. There was no difference in total arc of knee motion, the WOMAC scores at two years after the injury, and there were no significant differences between the groups with regard to the pain (p = 0.923), stiffness (p = 0.604), or function (p = 0.827).
The SF-36 scores at two years after the injury were significantly decreased, compared with the controls for both groups (p = 0.001 for the circular fixator group and p = 0.014 for the open reduction and internal fixation group). Seven (18%) of the patients in the open reduction and internal fixation group had a deep infection.
The number of unplanned repeat surgical interventions, and their severity, was greater in the open reduction and internal fixation group compared with the circular fixator group (p = 0.001). Any difference in the results was given as a P value only, without giving the Standard Deviation, and the statistical tests used were not mentioned. In general, the conclusions of the authors were somehow justified by the results.
Second study
The second study for discussion is ‘The strength of different fixation techniques for bicondylar tibial plateau fractures: a biomechanical study’ by Ahmad et al.7
This is a biomechanical experimental comparative study. Sawbones’ tibiae were used to create models of bicondylar tibial plateau fracture. The bicondylar tibial plateau fractures were created using a thin blade saw. The fractures were stabilised with one of five fixation methods:
- (A) dual buttress plating
- (B) a two-ring hybrid fixator with one inter-fragmentary screw on each side
- (C) a bar-ring hybrid fixator with one inter-fragmentary screw on each side
- (D) lateral buttress plate with medial monolateral external fixator
- (E) lateral buttress plate with medial inter-fragmentary screws
There were seven specimens in each fixation group. This was based on a pilot study to assess the variance in the measurement of fixation strength. The authors performed a power calculation to find the number of specimens needed to detect a difference. With seven specimens in each group, it is possible to detect a difference of 100N in the mean fixation strength with a power of 80% and alpha error at 0.05. The method of randomisation was not explained.
The main outcome measurement was clearly defined as the failure load of the fracture fixation defined as the applied load when the plastic displacement measured by any extensometers exceeds 3mm. The pattern in which failures happened was similar in all types of fixation studied, in the form of collapse of the medial tibial plateau followed by collapse of the lateral plateau.
The authors further closely examined failures; their results showed that the failure was due to the screw or wires cutting through the bone. Neither metalwork breakage, nor collapse in any external fixator has been observed. Although the dual buttress plating produced the highest mean failure load, it was not significantly higher than that of the two-ring fixator. All the fractures were reduced and fixed by a single orthopaedic surgeon. This does not allow for external validity when it comes to the assessment of outcome.
The authors gave most of the results in both P values and Confidence Interval (CI), which is more meaningful, and the conclusions were justified by the results. However, because it is done on bone models, we have to be cautious when generalising the results on human bones which could have different qualities, as well as the presence of soft tissues, as injuries could present an additional challenge in the management of these injuries.
Third study
The third study is ‘External fixation and limited internal fixation for complex fractures of tibial plateau fractures’ by Marsh et al.3
This was a prospective observational single-centre follow-up study of patients, level IV evidence. Twenty-one complex fractures of the tibial plateau in twenty patients were treated with closed reduction, interfragmental screw fixation of the articular fragments, and application of a unilateral half pin external fixator.
The included population was patients with tibial plateau fractures types IV-VI schatzker, bicondylar fractures, a dissociation of the shaft from the condyles in conjunction with an intra-articular fracture, or a tibial condylar fracture of the medial plateau, as well as a severe associated soft-tissue injury. As this is a case series study, there was no comparison with any other group.
Outcome measures used were radiological, looking at articular displacement, angulation and later on for post-traumatic osteoarthritis. These are all observer dependent, not validated and subject to interobserver difference as they have been monitored by three different observers.
Other outcome measures were subjective based on questionnaire, all patients were given two questionnaires: one to assess the function of the knee (the Iowa knee score) and one to assess the general health-related quality of life (the SF-36 general health survey), both of them are validated. However, the authors did not identify a primary outcome measure to decide the success of the treatment.
The average duration of external fixation was twelve weeks. The fixator was left in situ until the fracture had united in all but two patients. All of the fractures healed.
The complications with this technique were attributable primarily to the proximal half-pins of the external fixator. Seven patients needed antibiotics for an infection at a pin site, and two had septic arthritis that necessitated arthrotomy and debridement.
The average duration of follow-up was thirty-eight months. The range of motion of nineteen of the twenty-one knees was at least a 115º arc. Laxity was evident in seven knees, but no patient complained of instability of the knee. Radiographs showed malalignment of more than six degrees in three knees compared with the normal, contralateral knee and evidence of post-traumatic osteoarthritis in five knees.
The Iowa knee score, determined for nineteen patients, averaged 87 points. The SF-MI general health survey demonstrated that most patients had function close to that of age-matched controls. The authors concluded that external fixation with limited internal fixation is a satisfactory technique for the treatment of selected complex fractures of the tibial plateau.
Data from all eligible and included patients were analysed and accounted for. The statistical methods used to analyse data were not explained, therefore we do not know the significance of the results. Therefore, the conclusion of this study is not justified based on the results.
Discussion
Bicondylar tibial fractures are difficult to manage. The treatment of such fractures needs to pay specific attention to the soft tissue envelope around the knee.
Non-operative treatment for tibial plateau fractures is advised for minimally displaced closed fractures. Surgical treatment is advised for fractures with greater than 5mm displacement or greater than five degrees instability with varus or valgus stress.
The objective of treatment of tibial plateau fractures is precise reconstruction of the articular surfaces, stable fragment fixation allowing early motion, and repair of all concomitant lesions.
Operative techniques demand considerable surgical skills and mature judgment. If good results are to be achieved, the surgeon must have a thorough understanding of the local anatomy, the biomechanics of fracture fixation and patterns of fracture healing after fixation.
Pre-operative planning for surgical repair of these injuries is most important. The surgeon should individualise operative treatment with respect to a variety of factors, such as the patient’s age, pre-existing levels of activity, medical morbidity and expectations. Injury considerations should include the extent of fracture comminution and joint impaction, associated injuries, and most importantly, the condition of the soft tissues.4
Whether internal or external fixation techniques are used, appropriate management of the soft tissues is an important factor in the successful management of these severe injuries of the proximal tibia.
Although, the prognosis for surgically treated tibial plateau fractures has been improved as a result of a better understanding of soft tissue handling, pre-operative planning and fixation techniques. In a study by Moore et al2 of 320 patients with tibial plateau fractures and an average follow-up of 3.7 years, the complication rate after non-operative treatment (traction) was 8%. The complication rate of patients who underwent open reduction and internal fixation was 19%, infection being the main problem. The infection rate following open reduction and internal fixation in tibial plateau fractures varies between 2% and 11%.
Deep vein thrombosis in patients treated non-operatively is reported at 9% and at 6% for patients treated with open reduction and internal fixation. The surgical treatment of tibial-plateau fractures with ring, or hybrid, frames is an accepted alternative to non-operative management, or internal fixation. It combines the use of pins in the diaphysis with proximal wires in the periarticular region.
The discussed studies show that treatment of tibial plateau fractures with external fixation produce satisfactory results and is comparable to other methods such as internal fixation. Therefore, it could be utilised effectively in the selected group of patients who have very communited fractures of major soft tissue disruption. The advantage of our search results is that we had an RCT and an experimental study.
These studies discussed have demonstrated that external fixation must be combined with limited open or percutaneous reduction or articular surfaces and a possible minimal internal fixation. But we could not find a study comparing the external fixation with the relatively new device, the locking plate, which functions as an internal external fixator.
Further improvement of operative techniques and treatment protocols are necessary to improve the results in these serious injuries. There are relatively few papers regarding tibial plateau fractures according to the search strategy used for this review. This could be improved by looking at non-English published articles and by looking at unpublished studies from other sources such as conferences and congresses presentations to avoid coming to wrong conclusions due to publication bias. There is a need for long-term studies comparing open reduction and internal fixation for tibial plateau fractures with external fixation.
Author
Firas Arnaout, Trauma & Orthopaedics. Firas is currently working in Trauma & Orthopaedics as a Speciality Doctor at Worcester Royal Hospital. He obtained his MSc (Tr & Ortho) from Warwick University, researching the treatment of periprosthetic fractures with locking plates. His main interests are trauma and hand surgery, and he is also the editor of www.orthoguidance.com, an educational resource for orthopaedic professionals.
References
- Wyrsch, M.A. McFerran and M. McAndrew et al., Operative treatment of fractures of the tibial plateau: A randomized, prospective study, J Bone Joint Surg Am 78 (1996) (11), pp. 1646–1657.
- T.M. Moore, M.J. Patzakis and J.P. Harvey, Tibial plateau fractures, definition, demographics, treatment rationale and long term results of closed traction management or operative reduction, J Orthop Trauma 1 (1987) (2), pp. 97–119
- J.L. Marsh, S.T. Smith and T.T. Do, External fixation and limited internal fixation for complex fractures of the tibial plateau, J Bone Joint Surg Am 77 (1995) (5), pp. 661–673
- Panayiotis J. Papagelopoulos, Antonios A. Partsinevelos, George S. Themistocleous, Andreas F. Complications after tibia plateau fracture surgery Injury Volume 37, Issue 6, June 2006, Pages 475-484
- Jeremy A. Hall, Murray J. Beuerlein, Michael D. McKee and the Canadian Orthopaedic Trauma Society. Surgical Technique Application for Bicondylar Tibial Plateau Fractures, 2009; 91:74-88. doi:10.2106/JBJS.G.01165 J Bone Joint Surg Am.
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- Ahmad M. Alia, Michael Salehb, Stefano Bolongarob and Lang Yang. The strength of different fixation techniques for bicondylar tibial plateau fractures––a biomechanical study. Clinical Volume 18, Issue 9, November 2003, Pages 864-870.
- David G. Stevens, Rani Beharry, Michael D. McKee, James P. Waddell, and Emil H. Schemitsch, The Long-Term Functional Outcome of Operatively Treated Tibial Plateau Fractures, Journal of Orthopaedic Trauma Vol. 15, No. 5, pp. 312–320
