European Journal of Orthopaedic Surgery & Traumatology

, Volume 23, Issue 7, pp 809–818

Anatomical evaluation of the modified posterolateral approach for posterolateral tibial plateau fracture


  • Hui Sun
    • Department of Orthopaedic Surgery, Shanghai Sixth People’s HospitalShanghai Jiaotong University
    • Department of Orthopaedic Surgery, Shanghai Sixth People’s HospitalShanghai Jiaotong University
  • Guang Yang
    • Department of Orthopaedic Surgery, Shanghai Sixth People’s HospitalShanghai Jiaotong University
  • Hui-Peng Shi
    • Department of Orthopaedic Surgery, Shanghai Sixth People’s HospitalShanghai Jiaotong University
  • Bing-Fang Zeng
    • Department of Orthopaedic Surgery, Shanghai Sixth People’s HospitalShanghai Jiaotong University
Original Article

DOI: 10.1007/s00590-012-1067-z

Cite this article as:
Sun, H., Luo, C., Yang, G. et al. Eur J Orthop Surg Traumatol (2013) 23: 809. doi:10.1007/s00590-012-1067-z



The study was undertaken to evaluate the efficacy and safety of a posterolateral reversed L-shaped knee joint incision for treating the posterolateral tibial plateau fracture.


Knee specimens from eight fresh, frozen adult corpses were dissected bilaterally using a posterolateral reversed L-shaped approach. During the dissection, the exposure range was observed, and important parameters of anatomical structure were measured, including the parameters of common peroneal nerve (CPN) to ameliorate the incision and the distances between bifurcation of main vessels and the tibial articular surface to clear risk awareness.


The posterolateral aspect of the tibial plateau from the proximal tibiofibular joint to the tibial insertion of the posterior cruciate ligament was exposed completely. There was no additional damage to other vital structures and no evidence of fibular osteotomy or posterolateral corner complex injury. The mean length of the exposed CPN was 56.48 mm. The CPN sloped at a mean angle of 14.7° toward the axis of the fibula. It surrounded the neck of the fibula an average of 42.18 mm from the joint line. The mean distance between the opening of the interosseous membrane and the joint line was 48.78 mm. The divergence of the fibular artery from the posterior tibial artery was on average 76.46 mm from articular surface.


This study confirmed that posterolateral reversed L-shaped approach could meet the requirements of anatomical reduction and buttress fixation for posterolateral tibial plateau fracture. Exposure of the CPN can be minimized or even avoided by modifying the skin incision. Care is needed to dissect distally and deep through the approach as vital vascular bifurcations are concentrated in this region. Placement of a posterior buttressing plate carries a high vascular risk when the plate is implanted beneath these vessels.


Tibial plateau fracturePosterolateralSurgical approachAnatomy


Tibial plateau fractures are commonly encountered in clinical practice, whereas the posterolateral fractures of tibial plateau are relatively rare. The injury results from the tibial articular surface being stressed by the valgus and by axial force when the knee joint is in a flexed or semi-flexed position [1, 2]. Unstable flexion usually occurs unless residual impaction of the posterolateral tibial plateau is reduced [3]. Most of the current classification systems for tibial plateau use two-dimensional images, which usually direct surgeons to pay attention to medial and lateral fixation without thinking of posterior fixation. With careful review and application of the CT scan for the evaluation for these fractures, surgeons have realized the importance of posterior fixation in tibial plateau fractures and proposed the new three-column fixation conception [4]. By using an artificial bone fracture model, we have confirmed that the posterolateral buttress plate is biomechanically the strongest fixation for posterolateral shearing tibial plateau fracture [5]. But posterior column fractures, especially those involving the posterolateral section, are quite difficult to manage clinically.

In order to achieve anatomical reduction and firm buttress fixation for posterolateral fracture, growing understanding of the posterior column concept has resulted in efforts to surgically stabilize these fractures by using various posterior approaches in the knee joint [612]. In a case series of 11 patients [9], the reduction satisfaction rate was up to 91 % (10/11) by using a modified posterolateral reversed L-shaped approach. All patients had acceptable alignment, and only one had an approach-related complications: a sanguinous effusion lasting for more than 1 week postoperatively. This previous study suggests that a modified posterolateral approach may result in better exposure, for the treatment of the posterolateral shearing tibial plateau fracture with no need for fibular osteotomy. By reviewing literature, it is not difficult to find the existence of more or less complication in all various posterolateral approaches (Table 1).
Table 1

Comparison of different approaches for posterolateral tibial plateau fractures





Anatomical interface

Important structures

Exposure range



Complication or risk

Lobenhoffer et al. [6]


12 PL; 3 PL and PM

Lateral transfibular approach

Skin incised laterally; fibular neck osteotomy


PL and posterior of plateau

Posterior directly

PL buttressing

3 valgus or retrocurvatum

Bhattacharyya et al. [2]



An S-shaped incision midline superiorly and medial distally centered on popliteal fossa

MHGM retracted laterally, P and SM origin elevated off from medial to lateral


Entire posterior aspect of proximal tibia

Posterior directly

PL buttressing and lag screw

1 flexion contracture; 1 wound dehiscence

Carlson et al. [7]



Posterolateral approach (curvilinear S-shaped incision)

Between CPN and LHGM; SM divided from its attachment of fibula and tibia


PL plateau

Posterior directly

PL buttressing; subchondral screws and Kirschner wires

1 significant early knee flexion contracture

Egol et al. [8]


L-shaped or a “lazy S” lateral approach

ITB incised; anterior tibialis muscle elevated


No expose posterolateral directly

Indirectly; through split component, or a separate cortical window anteromedially

Plating laterally; subchondral screws

No statements

Tao et al. [9]



Modified PL approach (reversed L shaped)

Between CPN and LHGM; SM takes its origin off fibula and tibia


PL plateau

Posterior directly

PL buttressing; subchondral screw

1 sanguinous effusion

Chang et al. [10]



PL approach (straight incision)

Between CPN and LHGM; SM divided from its attachment of fibula and tibia


PL plateau; distal dissection be restricted to no more than 5 cm below articular level

Posterior directly

PL buttressing; at least 2–3 plate holes distal to fracture

1 peroneal nerve distribution paresthesia

Solomon et al. [11]



PL transfibular approach (longitudinal incision)

Fibular neck osteotomy; between ITB and CPN


PL aspect; PM to PCL and AL to posterior margin of ITB

Posterior directly

Lateral buttressing

No complications to approach. No symptoms to CPN

Frosch et al. [12]



PL approach (one PL incision)

PL exposure between LHGM and SM for reduction; a lateral standard arthrotomy for visualization


L-shaped area at dorsal side approximately 4–5 cm length from cranial to caudal direction

Posterior directly

PL buttressing and lateral buttressing

No complications

This study


Modified PL approach (reversed L shaped)

Between CPN and LHGM; SM takes its origin off fibula and tibia


PL plateau from PTFJ to PCL

Posterior directly

PL buttressing

N Number of cases, PL posterolateral, PM posteromedial, AL anterolateral, FH fibular head, CPN common peroneal nerve, ITB iliotibial band, MTL meniscotibial ligament, LCL lateral collateral ligament, PTFJ proximal tibiofibular joint, SN sural nerve, SSV small saphenous vein, MHGM medial head of gastrocnemius muscle, P popliteus, SM soleus muscle, LHGM lateral head of gastrocnemius muscle, BFT biceps femoris tendon, LIGA lateral inferior genicular artery, LSCN lateral sural cutaneous nerve, ATA anterior tibial artery, OIM opening of interosseous membrane, PLM peroneus longus muscle, TAM tibialis anterior muscles, DPN deep peroneal nerve, PLCC posterolateral corner complex, PCL posterior cruciate ligament, PA and PV popliteal artery/vein, TN tibial nerve, “–” unavailable

These approaches consist of varying effects of exposure and different impacts on surgical safety. There were few posterolateral approaches that do not require common peroneal nerve (CPN) dissection. With the nerve exposure, it will pose a great challenge and damage sometimes inevitably appear over the surgical course. It was believed from clinical experience and analysis that the posterolateral exposure cannot be extended distally by Carlson et al. [7]. They proposed that the trifurcation vessels traversing the interosseus membrane and the mass of muscle and tissue medial to the fibula make gaining an exposure past approximately 8–10 cm distal the lateral joint line difficult to safely obtain. Until now, there was no related anatomical study to confirm or rebut that statement. Besides, there is no clear conclusion about whether the existence of these important anatomical structures would affect the hardware implanting location. How about the risk?

In the present study, we evaluated the efficacy and safety of this approach using an anatomical method. Our objectives were to provide anatomical foundation for the future clinical application of this approach and to emphasize risk awareness while using this technique. By measuring the CPN parameters in approach, we want to ameliorate the incision to minimize or even avoid the CPN exposure. Through careful dissection and quantitatively measuring, the relationship between the possible implant site and the bifurcation of main vessels is clear-cut.

Materials and methods

Specimens preparation

Sixteen fresh, frozen (un-embalmed) lower extremities (thigh to toe) from eight adult cadavers with no bone pathology (trauma, or bone or soft tissue tumor) were experimented. The sex ratio of donors was balanced, and mean age was 49.3 years (39–61 years). The specimens were kept at −30 °C and thawed for 12 h at room temperature (20 ± 2 °C) before the experiment.

All specimens were dissected for a posterolateral reversed L-shaped approach. All knee joints were placed in a straight position, with popliteal fossa facing upwards. The dissection process was documented in detail.

Anatomy and observations

The skin incision of a posterolateral reversed L-shaped approach was a composite of horizontal and vertical incisions (Fig. 1a). It was designed as a right angle at the turning part, which would be beneficial for measurements and analysis. The horizontal incision began at medial point of the transverse crease of popliteal fossa. It traversed along the crease to the outside, then curved at lateral point of transverse crease and ran along the lateral margin of the lateral head of gastrocnemius muscle (LHGM) distally, parallel to the longitudinal line of fibula for a distance of about 10 cm.
Fig. 1

a Reverse L-shaped skin incision; b the SSV in the superficial layer of the popliteal fascia in the midline; c the CPN travels in the superior lateral quadrant of the approach, and the LSCN descends on the surface of LHGM, both nerves are located deep within the popliteal fascia. d The angle between the CPN and the longitudinal axis of fibula

The skin flap thus created was reflected inferomedially by ligating small saphenous vein (SSV) that identified in the midline, superficial to the popliteal fascia (Fig. 1b). The popliteal fascia was opened in line with horizontal incision. The CPN and lateral sural cutaneous nerve (LSCN) all located deep in popliteal fascia were dissected and preserved. Both nerves were identified in the superior lateral quadrant of the reversed L-shaped incision (Fig. 1c). The CPN was found beneath medial margin of the biceps femoris, between the tendon of biceps and LHGM. The CPN sloped at an angle close to the fibula and then surrounded the neck of fibula (Fig. 1d). The LSCN originates and emerges at a certain angle from the CPN in the upper corner of the popliteal fossa. It descended to cross the superficial surface of the LHGM to middle of leg. A clear distance between these two nerves could be seen in horizontal incision.

Once the gap between the LHGM and the soleus muscle (SM) was obtained by blunt dissection, the LHGM together with LSCN and the popliteal neurovascular bundle (popliteal artery/vein (PA/PV) and tibial nerve (TN)), which lies medially and deep to LHGM, were retracted medially (Fig. 2a). Slightly distal to the origin of fibular head (FH), the SM was sharply dissected vertically to its FH fibers and partial tibial fibers and retracted inferiorly (Fig. 2b). The posterolateral articular capsule, popliteus (P), proximal tibiofibular joint (PTFJ) and extracapsular posterolateral corner complex (PLCC) were then exposed. Beneath SM and distal to fibular neck, a large oval aperture for passage of the anterior tibial artery (ATA) was seen. It was the opening of interosseous membrane (OIM) (Fig. 2c). Near OIM, the ATA and posterior tibial artery (PTA) both originated at the bifurcation of PA, at the lower border of the P. Before the P and LHGM retracted medially, the lower border of the P was differentiated, and the PTA and ATA were preserved carefully with knee flexion. This procedure enabled the posterior surface of proximal tibia to be exposed. The fibular artery (FA) arose from PTA, distal to the bifurcation and passed obliquely toward the fibula, and then descended along the medial side of fibula (Fig. 2d). Sometimes, a small branch of FA, the arcuate artery, was also present. The lateral inferior genicular artery (LIGA) from the PA traversed horizontally on the surface of P and just proximally to FH in some specimens. It was always slender and exhibited significant anatomical variations among specimens.
Fig. 2

a The LHGM was retracted medially to protect the popliteal neurovascular bundle and expose the deep SM; b a part of SM was dissected vertically to its belly and retracted inferiorly. The FH, PTFJ and the posterolateral articular facet (asterisk) of tibial plateau were exposed after following capsulotomy. c Measurement of the distance between OIM and articular facet (asterisk); d measurement of the distance between FA origin and articular facet (asterisk)

A horizontal traverse incision was made through the posterolateral capsule to open the joint. The tibial insertion of the posterior cruciate ligament (PCL) was visible (Fig. 3a). The lateral sural neurovascular bundle, the lateral sural artery/vein (LSA/LSV) emerging from the PA/PV and the muscular branch of LGMB originating from TN, was subsequently dissected through the gap between the two heads of gastrocnemius muscle (Fig. 3b). In most specimens, the LSA arose from PA at the level of femoral condyles and entered the proximal LHGM. Its course was mainly covered by LHGM. The vein and muscular branch were accompanied by the artery.
Fig. 3

a The posterior aspect of plateau and the tibial insertion of PCL were exposed by knee flexion; b the interval between two heads of gastrocnemius muscle was revealed by dissection. The LSA/LSV emerged from the PA/PV. The muscular branch of LHGM originated from the TN


The following parameters were measured: the length of exposed CPN; the angle at which the CPN sloped toward the longitudinal shaft of fibula; the distance between the articular line and the position where CPN surrounded the fibular neck, and the origin of LIGA, OIM and FA; the neurovascular data of the LHGM.

Parameters were measured using a slide calipers (0.02-mm precision) and an angle gauge (0.1° precision). Measurements were made without structures damaging or torsional deformation. All measurements were confirmed by two independent experienced orthopedists.


The mean length of exposed CPN in incision was 56.48 mm (range: 50.12–62.56 mm). The CPN sloped at a mean angle of 14.7° (range: 12–18°) toward the axis of fibula. The point at which the CPN wound around fibular neck was on average 42.18 mm (range: 38.12–46.44 mm) from articular line.

The LIGA diverged from PA at a mean of 10.22 mm (range: 8.68–12.18 mm) distal to the joint line. The mean distance between the OIM and articular surface was 48.78 mm (range: 45.86–51.36 mm). The FA originated from PTA at a mean of 76.46 mm (range: 72.56–80.44 mm) from the joint line. The LSA originated from PA at a mean of 12.60 mm (range: 10.56–14.74 mm) proximal to articular surface. The mean length of LSA was 32.16 mm (range: 30.20–34.52 mm).


Exposure of the tibial plateau can be gained through a variety of approaches. The selection of a surgical approach for the treatment of tibial plateau fractures is an important decision. An excellent approach should provide adequate articular visualization, combined with preservation of all vital structures and minimal soft tissue and osseous devitalization [13]. The anterior (anteromedial or anterolateral) approaches were previously favored for treating posterior column tibial plateau fractures. The limitations and disadvantages in visualizing and manipulating the posterior column fracture through an anterior approach are becoming increasingly recognized [2, 11]. Moreover, manipulation of posterolateral fragments is seldom successful using a lateral approach alone because both the fibula and the strong ligamentous and tendinous structures of the popliteal corner prevent reduction and fixation [14]. Egol et al. [8] introduced a lateral approach through which posterolateral tibial plateau fractures could be repaired. In an attempt to protect the PTFJ and CPN, the posterolateral masses were reduced indirectly only through a lateral split fracture gap or an additional window opened in the medial cortex. Both procedures caused significant disruption; they did not guarantee effective fracture reduction, made buttressing more difficult and did not always correct instability. In posterolateral tibial plateau fractures, split fragments tend to be displaced posteriorly. The resulting shearing stress is not generally counteracted by simple lateral plating fixation or by sagittal antero-posterior screw fixation. Thus, it is inadvisable to expose and manipulate posterolateral fractures via anterior or lateral approaches.

Consequently, the posterior approach has become increasingly mainstream for the surgical management of posterolateral tibial plateau fractures. A comparison of different posterior approaches and ours for treatment of the posterolateral tibial plateau fracture is reviewed in Table 1. According to the location of incision, the posterior approaches for posterolateral fractures can be divided into two types: midline incision and posterolateral local incision. Bhattacharyya et al. [2] exposed the entire posterior aspect of proximal tibia by retracting the medial head of gastrocnemius muscle together with the neurovascular bundle laterally through a posterior approach, using an S-shaped midline incision superiorly and medial distally. Using this technique, posterior column fractures (including posterolateral fractures) could be exposed, reduced and fixed without dissecting the LHGM. The fact that posterolateral fracture could be successfully managed using this real posteromedial approach warrants careful consideration. So far, for posterolateral fracture, the vast majority approaches were concentrated in local. As far as the local posterolateral approaches were concerned, they could be obviously differentiated according to whether with fibular osteotomy [6, 11] or not [7, 9, 10, 12]. The FH plays the vital role of an attachment structure in the lateral and posterolateral aspect of the knee. Thus, osteotomy of the FH is an obvious iatrogenic trauma. After osteotomy, the PTFJ is divided, and the FH is reflected upward with the meniscotibial ligament, ITB and LCL attachments. During closure, the FH is fixed back with extra internal fixation, such a lag screw or a tension band. Because the FH is placed under different tensions during movement in various directions, there is a risk of fixation failure at the osteotomy site even results in nonunion or delayed union. It also remains unclear whether, and to what extent, the fibular osteotomy and separation of PTFJ influence mechanical transduction in the tibia and fibula and load distribution in the ankle joint.

Although all these posterolateral approaches were largely identical with only minor diversity in terms of exposure range and anatomical interface, there were something that could not be ignored, all these approaches were associated with a damage risk of CPN exposure [612]; most of these approaches with a risk of flexion contractures postoperatively on account of longitudinal skin incisions across the popliteal crease [7, 10, 15]; and no literature could be followed with respect to the spatial relationship of important structures in the posterolateral region, especially impact on hardware implanting.

A reversed L-shaped posterolateral approach to knee was first applied by Minkoff et al. [16] for the management of a single case of osteoid osteoma that involved the posterolateral proximal tibia medial to the PTFJ, 1 cm beneath the articular surface. The skin incision for this approach was slightly different from that used in our study. Our reversed L-shaped approach apart from other posterolateral approaches makes full use of the skin wrinkles of popliteal crease to reduce incision tension, meanwhile to keep away from the tendency of postoperative flexion contractures. Although the posterolateral reversed L-shaped approach has been preliminarily and successfully applied in a relatively small number of fracture patients [9], the actual difficulty and risks of the operation have not been surveyed by anatomical experiments before. The pathway of the CPN was fully exposed in our study. However, we suggest that surgeons should try to avoid exposing the CPN or reduce exposure using a modified incision, further to minimize damage to tiny branches of CPN and the blood supply of nerve. Based on data related to CPN obtained during dissection, we suggest that the incision shape could be changed from a reversed right-angle L shape to an obtuse curved line to avoid exposing the CPN (Fig. 4). At the same time, the accurate course of CPN should be kept firmly in mind. Gentle traction to the superior lateral quadrant of the approach should be adopted intraoperatively.
Fig. 4

The approach can be modified using a skin incision that enables the CPN to be avoided. The course of CPN is shown by the yellow solid line. The reverse L-shaped skin incision used in our study is shown by the red dotted line. The expected modified incision is shown by the blue dotted line

According to our morphological statistics for the posterolateral fracture of tibial plateau [5] and the findings of other researchers [10], the cortical split length on the coronal plane of the posterolateral fracture is between 28 and 30 mm from the articular rim to the distal tip. In our survey, the OIM was located approximately 48 mm distally to the plateau articular facet (Fig. 5a). Thus, implantation of an antiglide plate often needs to go beyond the level of OIM and cross deep toward the ATA. Owing to the unique morphological characteristic of the posterolateral aspect of proximal tibial metaphysis and the obstruction of FH, the buttressing implant is needed to place medially in a slanting position and have to close to the PA or trifurcation vessels (Fig. 5b), as shown in a real case (Figs. 6, 7). When stripping in the deep posterior compartment underneath the SM, surgeons should be aware that distal and deep exposure may be limited by the presence of ATA, PTA, FA and its arcuate artery. If placement of a long posterior buttressing plate is necessary, these vessels need to be freed and carefully protected, so as to avert huge intraoperative bleeding, hematoma formation or postoperative sanguinous incision effusion.
Fig. 5

a The posterior aspect of proximal tibia. The common cortical split length of the posterolateral fracture on the coronal plane was 28–30 mm (red solid line). The distance between OIM and articular facet is shown by the blackdotted line. The distance between FA origin and articular facet is shown by the bluedottedline. b A posterolateral split fracture pattern on the synbone model was antiglided by a limited contact dynamic compression plate (LC-DCP). Owing to the unique morphology and anatomy of the obstruction of FH, the buttressing implant is needed to place medially in a slanting position, close to the PA or trifurcation vessels
Fig. 6

A case of posterolateral fracture of tibial plateau. a, b The preoperative AP and lateral roentgenograms of the left knee. It is difficult to identify the fracture on both view. c, d, e The CT images of the left knee with transverse scan, and coronal, sagittal plane reformation. A posterolateral fracture of tibial plate is clearly discernible
Fig. 7

The postoperative X-ray views. The buttressing implant was placed medially in a slanting position. The collapsed articular surface has been elevated with bone graft, and the split fragment has been buttressed by a 3.5-metaphyseal locking compression plate (LCP). a The AP view; b the lateral view

According to our clinical experience, there are a few things worth noting in the process of these approaches: (1) Excessive medial traction of LHGM should be avoided. There might also be increased separated tension between LSCN and CPN if it is retracted excessively and might be injury to the nerve. (2) To avoid injury to the neurovascular bundle in popliteal space, dissection from lateral to medial should be undertaken beneath popliteus muscle. (3) Because slender, short neurovascular supplies of the LHGM are located deep within the medial and proximal LHGM, Hoffman retractor, rather than Celiac or S-shaped retractor, should not be placed excessively deep, and the muscle belly should be used to protect against damage to the blood supply and innervation of LHGM. A flow diagram of Fig. 8 may be helpful for surgeons to actually operate this modified posterolateral reversed L-shaped approach for posterolateral fracture.
Fig. 8

A flow diagram simplified the operational process of our approach


The posterolateral reversed L-shaped approach can be effectively modified and safely used as a routine surgical approach for treating the posterolateral tibial plateau fractures. A modified skin incision helps to significantly reduce or even avoid exposing of the CPN. Vital vascular bifurcations (such as the LIGA, ATA, PTA and FA) are concentrated in the posterolateral aspect of proximal tibia, and placement of buttressing plate beneath these vessels in most cases carries a high risk. Because of the limited supply of cadaver specimens, the clinical value of this modified approach needs to be verified in clinical practice.


The authors would like to thank the Department of Anatomy, Tongji University School of Medicine in Shanghai for assistance in the experiments and for supplying the cadaver specimens. No benefits in any format have been or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.

Conflict of interest


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