Introduction

The fractures of the tibial plateau are represented by all the articular fractures of the upper end of the tibia, except for the fractures of intercondylar eminence. Their surgical treatment profited from technical progress of the arthroscopy and the synthesis. Its complications are not rare. Epiphyseal necrosis, rare but serious, is often the fact of the complex depressions in mosaic .

We present a case of idiopathic osteonecrosis of the lateral tibial plateau occurred at a well followed diabetic patient, after a classic synthesis of a tibial plate mixed fracture (separation and depression).

Case report

A 59 year old patient, diabetic type 2, presented after a traffic accident, a closed traumatism of the left knee. It was received 3 hours after its traumatism. The clinical and radiographic examination had found a mixed fracture (depression and separation) of the lateral tibial plateau without distal vascular and nervous attack (Figure 1).

Figure 1

Figure 1: Lateral mixed fracture of the left tibial plateau (anteroposterior and lateral views)

We performed the surgery 3 days after with an elevation, osseous grafting and fixation by L-plate. We used a lateral Gernez approach and a sub-meniscal arthrotomy to assess the quality of the reduction. Per-operative exploration had found no meniscal or ligamentous injury. The X ray control showed a satisfactory reduction (Figure 2).

Figure 2

Figure 2: Post operative X rays (anteroposterior and lateral views)

The immediate post-operative evolution was without clinical and biological infection. Functional rehabilitation had been undertaken 15 days afterwards. At 1 year, the functional and anatomical evaluation had found a mechanical pain, a slight limping and a secondary depression of the elevated fragment (Figure 3).

Figure 3

Figure 3: X ray control (anteroposterior and lateral views) at 1 year of retreat showing a secondary depression of the elevated fragment

The last evaluation at 3 years of retreat had found an exacerbation of the pain and the slight limping with a perimeter of walk without pain lower than 100m, a lateral laxity in extension, a 0/0/135° mobility of the knee and a lateral tibial plate osteonecrosis (Figure 4).

Figure 4

Figure 4: X ray control (anteroposterior and lateral views) at 3 years of retreat showing lateral tibial plateau necrosis

A material removal associated with a bone puncture was proposed but refused by the patient. It was lost sight of the fact thereafter.

Discussion

The first description of the osteonecrosis of the tibial plate is allotted, in french literature to Angelejan in 1976 and later in english literature to Houpt [₅₁₁]. The primary form known as idiopathic or spontaneous was largely published contrary to the secondary form [₂₆].

Narvaez and al. tried to work out criteria making it possible to make the difference between the primary and the secondary forms [₆]. The idiopathic osteonecrosis occurs without any risk factors while the secondary osteonecrosis would be caused by a number of well-known predisposing factors acting alone or in concert. These risk factors can be local, such gravity of the injuries and the aggressiveness of the surgical treatment, and/or general like the age, osteoporosis, metabolic diseases and the steroid therapy [₃₈]. Therefore there would be significant differences between these 2 forms especially in the clinical presentation, the location and the extension of the necrosis as well as aspects with the MRI [₆₈]. That is due to a difference of the pathogenic mechanism.

The medial tibial plate, more often reached, is the prerogative of the primitive form. When the necrosis occurs on the lateral tibial plate, the secondary aetiology is strongly suspected. Occurred of one necrosis after a surgical treatment is rare [₃₄₁₂]. It is explained by the difficulties of the surgical treatment of the fractures of the upper end of the tibia related to necrosis of a devitalized fragment [₅₁₂]. This necrosis is often ignored and allotted to the failure of synthesis [₃₁₂]. Recently Johnson and al. described occurred of necrosis tibial plate after arthroscopic surgery for meniscal lesions [₄].

Its late diagnosis explains the need for a confirmation [₃₇₁₀]. Before the anatomopathological examination and after the bone scintigraphy or bone scan, the MRI is currently the most significant and most specific examination [_1245811]. The histological confirmation is sometimes difficult to have [₈₁₁]. The evolution of necrosis is variable, often pejorative with a progressive aggravation [₈₉]. It was initially appreciated starting from a modification with the knee of the classification of Arlet and Ficat [₁₁]. Carpintero and al. [₄] proposed a radiological staging with histological proof whereas Lonner and al. [₅] classify necrosis according to the spectrum of subchondral changes observed with the MRI.

The treatment of the osteonecrosis goes from bone grafting, tibial osteotomy to the knee replacement, total or unicompartmental, to measure [[[[7, 9, 10, and 11]]]]. The management of predisposing factors, local and general, in the secondary forms must allow the reduction of which has occurred necrosis it [₃₄₆₈].

Conclusion

The fractures of the tibial plateau are a current pathology in trauma department. Occurred of complication is often due to the surgical gesture. Osteonecrosis is a rare form whose prevention passes by the correct management of general but especially local factors.