Abstract
Posterolateral corner injuries of the knee are relatively rare; however, they can result in significant long-term disability without appropriate treatment. They often occur in the setting of multiligament knee injuries, and as a result, diagnosis and management can be challenging. Severe injuries often require reconstruction, and both anatomic and nonanatomic techniques exist. We describe our preferred operative technique to reconstruct the fibular collateral ligament and posterolateral corner using a single Achilles tendon allograft.
Injuries to the posterolateral corner (PLC) of the knee commonly occur as a result of high-energy trauma involving hyperextension and either a varus or external-rotation force about the knee. Frequently, other ligaments are also injured; this makes accurate diagnosis and subsequent management challenging.
The anatomy of the PLC is complex. The major structures include the fibular collateral ligament (FCL), the popliteofibular ligament (PFL), and the posterolateral capsule, which are the primary static stabilizers, and the popliteus tendon, which is an important dynamic and static stabilizer. Combined, these structures provide restraint to both posterolateral rotation of the tibia and varus opening forces.
Reconstruction of PLC injuries is an evolving concept, and numerous techniques have been developed with slight variations.1-11 In this article we describe our preferred technique, which uses a single Achilles tendon allograft, with anatomic fibular and femoral tunnels and a posterolateral capsular shift (Fig 1). This technique was developed by the senior author (B.A.L.) and is less complex than some anatomic reconstruction techniques because of elimination of the transtibial tunnel, but it still takes into account the posterolateral stabilizers of the knee and their respective anatomic relations.12
Fig 1.
(A) Pictorial representation of our single–Achilles tendon allograft PLC reconstruction technique depicting the femoral and transfibular tunnel placement and final construct, including fixation with interference screws in the femoral tunnels and (B) posterolateral capsular shift and imbrication to the graft construct. (Reprinted with permission.12)
Illustrative Case
A 16-year-old boy presented with left knee instability after a hyperextension injury during football that occurred approximately 4 weeks before presentation. At the time of the injury, he felt a pop and tearing sensation in the back and lateral aspects of the knee. He had immediate posterolateral knee pain, numbness to the dorsum of the foot, and instability with any attempt at weight bearing. In the 4 weeks that ensued, his numbness spontaneously resolved. Physical examination at presentation showed 1+ effusion, a negative Lachman test, positive posterior drawer and posterior sag tests, positive dial tests at both 30° and 90°, a positive external rotation drawer test, and a positive Marx spin test. In addition, the patient had 2+ opening to varus stress at full extension and at 30°. He was found to be neurovascularly intact on presentation. The examination findings were consistent with a complete disruption of the posterior cruciate ligament (PCL) and the PLC. For the purposes of this illustrative case and technique, we will focus only on treatment of the PLC. Magnetic resonance imaging showed a complete PCL tear and PLC injury, with disruption of the FCL, popliteus tendon, PFL, and posterolateral capsule.
PLC Reconstruction Technique
Graft Selection and Preparation
Our PLC reconstruction technique uses a fresh-frozen, nonirradiated Achilles tendon allograft with a contiguous bone block. A graft length of at least 22 cm is required. The bone block is shaped into a 9 × 23–mm (diameter × length) cylinder. The segment of tendon allograft adjacent to the bone block will re-create the FCL and is 9 mm in diameter; the rest of the allograft, which must pass through the fibular tunnel, will re-create the PFL and is 7 mm in diameter. The free tendon end is secured with a No. 1 Vicryl suture (Ethicon, Cincinnati, OH) to facilitate later graft passage. The graft is also treated with MTF Cascade platelet-rich plasma (MTF Sports Medicine, Edison, NJ).
Patient Preparation and Positioning
Once satisfactory general anesthesia is attained, both knees are examined clinically and with fluoroscopic stress views to confirm the instability pattern. We then perform any arthroscopic procedures that are required, including anterior cruciate ligament (ACL) and/or PCL reconstruction in the setting of a multiligamentous knee injury, as well as any meniscal or articular cartilage treatment. Proceeding to the PLC reconstruction, we position the operative extremity on a Bone Foam ramp (Bone Foam, Plymouth, MN) to allow for easy surgical access and lateral imaging. A tourniquet is used unless a relative contraindication exists, such as recent vascular stent placement, bypass, or severe arterial calcification in the operative extremity.
Surgical Approach
A curvilinear lateral incision centered over the anterior border of the fibula and over the lateral epicondyle of the femur is used (Fig 2, Table 1). Full-thickness flaps are created both anteriorly and posteriorly to expose the iliotibial band (ITB) and biceps femoris muscle. Next, careful blunt dissection posterior to the biceps femoris is performed to isolate the peroneal nerve (Fig 3), which is then protected throughout the procedure.
Fig 2.
Curvilinear skin incision for PLC reconstruction of left knee. The patient is supine. Shown in the photograph are the fibular head (rightward-pointing arrow), joint line (downward-pointing arrow), and lateral epicondyle (upward-pointing arrow).
Table 1.
Key Points for Reconstruction of PLC
| Adequately expose the lateral-sided structures with an incision running from the proximal one-third of the fibula to the lateral femoral epicondyle. |
| Ensure that the peroneal nerve is adequately exposed and protected throughout the case. |
| Obtain adequate exposure of the fibular head anteriorly and posteriorly. |
| Confirm accurate femoral socket and fibular tunnel placement using fluoroscopic guidance. |
| Place the femoral sockets at the anatomic insertions of the popliteus and FCL as described by LaPrade et al.13 |
| Ensure isometry of the graft throughout the full range of motion before final fixation. |
| Advance the posterolateral capsule using FASTak suture anchors placed at the distal femoral articular margin. |
| Mold the hinged knee brace into slight varus to help protect the reconstruction. |
Fig 3.
Soft-tissue dissection exposing peroneal nerve (downward-pointing arrow) with retraction of biceps femoris tendon (upward-pointing arrow). The retractor is 1 cm proximal to the fibular head.
Next, we turn our attention to the fibular head. We perform a subperiosteal dissection using electrocautery both anteriorly and posteriorly to expose landmarks and gain access for the fibular tunnel. Posteriorly, the dissection is continued until the entire posterior aspect of the fibular head is cleared and the posteromedial tubercle can be palpated. This will be the exit point for the fibular tunnel. The anterior dissection exposes the anterolateral insertion point of the FCL, which will be the starting point for the fibular tunnel.
We then expose the lateral aspect of the femur. The ITB is split longitudinally midway between its anterior and posterior borders from the proximal extent of the incision to the Gerdy tubercle. Once through the ITB, we make a capsular incision near the joint line and dissect the capsule off of the distal aspect of the femur, being careful not to damage the lateral meniscus or its attachments. This creates a posterolateral capsular flap for the capsular shift. To facilitate the capsular shift, we place 2 or 3 FASTak anchors (Arthrex, Naples, FL) near the articular margin of the distal femur, and after shifting the capsule anteriorly, we pass the suture ends through the capsule. These will be tied near the conclusion of the case.
At this time, we also locate the proximal femoral insertion of the popliteus in the anterior fifth of the popliteal sulcus, which is a kidney bean–shaped indentation on the lateral aspect of the distal femur. If the damage to the popliteus muscle is only midsubstance, the popliteus tendon can be located here (Fig 4), dissected free, and then captured with a No. 1 Vicryl suture for later incorporation into the reconstruction. Dissection of the popliteus tendon is continued distally through the popliteal hiatus toward the fibular head to create a soft-tissue tunnel for eventual graft passage.
Fig 4.
Soft-tissue dissection exposing popliteus tendon (leftward-pointing arrow), lateral femoral condyle including popliteal sulcus (rightward-pointing arrow), and tunnel created in fibular head (downward-pointing arrow).
PLC Reconstruction
The next step in PLC reconstruction is the creation of sockets or tunnels in the femur and fibula that will function as fixation points for the graft. These tunnels are positioned based on palpable bony landmarks and are verified by fluoroscopy. The first socket is created at the insertion point of the native popliteus tendon (at the anterior one-fifth of the popliteal sulcus on the lateral aspect of the lateral femoral condyle). A Beath pin is drilled at this location, heading in a slightly anterior and proximal direction (Fig 5), which will avoid both the femoral notch and the ACL tunnel if a concomitant ACL reconstruction has been performed. The Beath pin is used as a guide to create a 9 × 25–mm (diameter × depth) socket. The bone plug of the allograft is docked into this socket and secured with a 7 × 23–mm BioComposite screw (Arthrex). The soft-tissue component of the graft is then passed through the popliteal hiatus to the posterior aspect of the fibula.
Fig 5.
Anteroposterior fluoroscopic view of socket placement for popliteus portion of PLC graft.
The next bone tunnel is created in the fibula. A K-wire is drilled from the insertion site of the FCL (a palpable tubercle on the anterolateral aspect of the fibular head), heading in a proximal and medial direction, to a tubercle located on the posteromedial aspect of the fibular head. Placement is confirmed with fluoroscopy (Fig 6), and then a 7-mm tunnel is reamed over the K-wire. The peroneal nerve is protected at all times. The Achilles graft is then passed from posterior to anterior through the tunnel, re-creating the PFL.
Fig 6.
Lateral fluoroscopic view of fibular tunnel placement from anterolateral fibular head to posteromedial insertion of PFL at fibular styloid.
The last socket is created at the proximal insertion site of the FCL. This location is slightly posterior and proximal (approximately 3.1 mm posterior and 1.4 mm proximal) to the lateral epicondyle and approximately 18.5 mm from the center of the insertion of the popliteus tendon.13 A Beath pin is drill into the femur at this location, heading in a direction that parallels the previously drilled popliteal socket. The positioning of the Beath pin is checked with fluoroscopy and, as importantly, is checked clinically for isometry (Fig 7). To do so, the free end of the Achilles graft is looped tightly around the Beath pin while the knee is put through a range of motion. If the graft lengthens during flexion, the Beath pin needs to be moved posteriorly; if the graft shortens during flexion, the Beath pin needs to be moved anteriorly. Once the isometric point is confirmed, a 7-mm socket is reamed at a depth of 30 or 40 mm.
Fig 7.
Anteroposterior fluoroscopic view of pin placement for FCL tunnel from anatomic insertion of FCL to superomedial femur running parallel to popliteal socket.
Next, the soft-tissue end of the graft is trimmed so that no more than 25 to 30 mm of graft will need to be pulled into the femoral FCL socket. A TightRope (Arthrex) is secured to the free end of the Achilles graft, and the Beath pin is exchanged for a spade-tipped guide pin, which allows osseous length measurement and then is used to pass the TightRope through the femur so that it can be flipped medially and tensioned. Tensioning is performed with the knee in 30° of flexion, valgus, and neutral rotation. As backup fixation, a 7 × 23–mm BioComposite screw is inserted into the femoral FCL socket (Fig 8) and a 6 × 23–mm BioComposite screw is inserted into the fibular tunnel.
Fig 8.
(A) Anteroposterior and (B) lateral fluoroscopic views of final graft reconstruction fixation showing popliteus graft with BioComposite screw (arrow with no tail), FCL limb with TightRope button on lateral femur (arrowhead), fibular graft fixation with BioComposite screw (arrow with tail), and 3 capsular suture anchors (triangle).
Finally, if the native popliteus limb is of adequate tissue quality, it is secured to the grafted popliteus limb and FCL with No. 1 Ethibond (Ethicon, Somerville, NJ) (Fig 9). With the knee in full extension, the capsule is closed with the previously placed FASTak anchors. A routine closure of all the fascial intervals, subcutaneous tissue, and skin is then performed. The knee is placed in a hinged rehabilitation knee brace locked in full extension and molded to produce a slightly valgus positioning of the knee (Fig 10).
Fig 9.
Intraoperative photograph of final PLC construct with popliteus portion of graft (downward-pointing arrow) and fibular collateral portion of graft (upward-pointing arrows).
Fig 10.
Postoperative anteroposterior radiograph of knee placed in hinged rehabilitation brace with slight valgus mold.
Postoperative Protocol
Postoperatively, we follow the rehabilitation protocol outlined by Fanelli.14 The rehabilitation brace is locked in full extension for 3 weeks, and then prone passive knee flexion is initiated. The patient remains only toe-touch weight bearing for the first 6 weeks postoperatively. After 6 weeks, progressive weight-bearing, range-of-motion, closed–kinetic chain strengthening, and proprioception exercises are started. Once the swelling has subsided, typically around 6 to 8 weeks postoperatively, a custom unloader brace with a mild valgus moment is fitted; the patient wears this during all weight-bearing activities for the first year postoperatively and during all athletic activities for life.
Discussion
Reconstruction of the PLC is important to help restore knee stability. Untreated or improperly treated injuries can result in significant disability and limit patients' quality of life. Numerous reconstruction techniques have been described in the literature previously, each attempting to re-create the anatomy of and the stability provided by the native PLC structures; however, the results have been inconsistent.1,3,5,6,8,11,15,16
Our preferred technique uses the anatomic tunnel placement described by Arciero2 to reconstruct the femoral and tibial insertions of the FCL and PFL combined with a posterolateral capsular shift technique as described by Fanelli.3 A biomechanical analysis of different PLC reconstruction techniques found that PLC reconstruction with 2 femoral tunnels and an oblique fibular tunnel best restored lateral-side kinematics.17
A comparison of our PLC reconstruction in knees with injuries to 2 ligaments versus multiligament-injured knees showed no significant difference between groups in International Knee Documentation Committee (IKDC) or Lysholm scores or clinical stability.12 Recently, Geeslin and LaPrade18 and Camarda et al.19 reported satisfactory outcomes with mean IKDC scores of 89.5 and 88.5, respectively, for isolated PLC reconstructions using a fibular tunnel. For combined PLC and cruciate injuries, Geeslin and LaPrade reported a mean IKDC score of 78.5.
The described technique has a number of advantages. The primary advantage is the elimination of the transtibial tunnel and extra graft passage and fixation, making it less complex and less surgically invasive, with a lower risk of injury to the popliteal artery, than other techniques. In addition, the inclusion of the posterolateral capsular advancement and imbrication to the graft construct adds an additional static PLC stabilizer to the reconstruction. The primary disadvantage of our technique is that the passage and tensioning of the graft through only the fibula necessitate that the proximal tibiofibular joint be intact because there is no transtibial tunnel.
Reconstruction of the PLC is an important part of the management of the multiligament- injured knee. This article and Video 1 have presented our preferred PLC reconstruction technique, which we have previously reported.12 Careful planning and accurate reconstruction of the injured PLC structures can help restore native knee kinematics and provide satisfactory clinical and functional outcomes.
Footnotes
The authors report the following potential conflict of interest or source of funding: M.J.S. receives support from Arthrex, Stryker, USA Hockey Foundation. B.A.L. receives support from Clinical Orthopaedics and Related Research, Arthrex, National Institutes of Health, VOT Solutions.
Supplementary Data
Open technique for PLC reconstruction after multiligament knee injury in left knee.
References
- 1.Stannard J.P., Brown S.L., Robinson J.T., McGwin G., Jr., Volgas D.A. Reconstruction of the posterolateral corner of the knee. Arthroscopy. 2005;21:1051–1059. doi: 10.1016/j.arthro.2005.05.020. [DOI] [PubMed] [Google Scholar]
- 2.Arciero R.A. Anatomic posterolateral corner knee reconstruction. Arthroscopy. 2005;21:1147.e1–1147.e5. doi: 10.1016/j.arthro.2005.06.008. Available at www.arthroscopyjournal.org. [DOI] [PubMed] [Google Scholar]
- 3.Fanelli G.C. Surgical treatment of lateral posterolateral instability of the knee using biceps tendon procedures. Sports Med Arthrosc. 2006;14:37–43. doi: 10.1097/00132585-200603000-00007. [DOI] [PubMed] [Google Scholar]
- 4.LaPrade R.F., Johansen S., Wentorf F.A., Engebretsen L., Esterberg J.L., Tso A. An analysis of an anatomical posterolateral knee reconstruction: An in vitro biomechanical study and development of a surgical technique. Am J Sports Med. 2004;32:1405–1414. doi: 10.1177/0363546503262687. [DOI] [PubMed] [Google Scholar]
- 5.Zantop T., Petersen W. Modified Larson technique for posterolateral corner reconstruction of the knee [in German] Oper Orthop Traumatol. 2010;22:373–386. doi: 10.1007/s00064-010-9030-9. [DOI] [PubMed] [Google Scholar]
- 6.Kim S.J., Kim T.W., Kim S.G., Kim H.P., Chun Y.M. Clinical comparisons of the anatomical reconstruction and modified biceps rerouting technique for chronic posterolateral instability combined with posterior cruciate ligament reconstruction. J Bone Joint Surg Am. 2011;93:809–818. doi: 10.2106/JBJS.I.01266. [DOI] [PubMed] [Google Scholar]
- 7.Angelini F.J., Helito C.P., Tozi M.R. Combined reconstruction of the anterior cruciate ligament and posterolateral corner with a single femoral tunnel. Arthrosc Tech. 2013;2:e285–e288. doi: 10.1016/j.eats.2013.03.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Jakobsen B.W., Lund B., Christiansen S.E., Lind M.C. Anatomic reconstruction of the posterolateral corner of the knee: A case series with isolated reconstructions in 27 patients. Arthroscopy. 2010;26:918–925. doi: 10.1016/j.arthro.2009.11.019. [DOI] [PubMed] [Google Scholar]
- 9.Rios C.G., Leger R.R., Cote M.P., Yang C., Arciero R.A. Posterolateral corner reconstruction of the knee: Evaluation of a technique with clinical outcomes and stress radiography. Am J Sports Med. 2010;38:1564–1574. doi: 10.1177/0363546510363462. [DOI] [PubMed] [Google Scholar]
- 10.Dickens J.F., Kilcoyne K., Kluk M., Rue J.P. The posterolateral corner: Surgical approach and technique overview. J Knee Surg. 2011;24:151–158. doi: 10.1055/s-0031-1284727. [DOI] [PubMed] [Google Scholar]
- 11.Lee K.H., Jung Y.B., Jung H.J. Combined posterolateral corner reconstruction with remnant tensioning and augmentation in chronic posterior cruciate ligament injuries: Minimum 2-year follow-up. Arthroscopy. 2011;27:507–515. doi: 10.1016/j.arthro.2010.11.007. [DOI] [PubMed] [Google Scholar]
- 12.Schechinger S.J., Levy B.A., Dajani K.A., Shah J.P., Herrera D.A., Marx R.G. Achilles tendon allograft reconstruction of the fibular collateral ligament and posterolateral corner. Arthroscopy. 2009;25:232–242. doi: 10.1016/j.arthro.2008.09.017. [DOI] [PubMed] [Google Scholar]
- 13.LaPrade R.F., Ly T.V., Wentorf F.A., Engebretsen I. The posterolateral attachments of the knee: A qualitative and quantitative morphologic analysis of the fibular collateral ligament, popliteus tendon, popliteofibular ligament, and lateral gastrocnemius tendon. Am J Sports Med. 2003;31:854–860. doi: 10.1177/03635465030310062101. [DOI] [PubMed] [Google Scholar]
- 14.Fanelli G.C. Posterior cruciate ligament rehabilitation: How slow should we go? Arthroscopy. 2008;24:234–235. doi: 10.1016/j.arthro.2007.09.009. [DOI] [PubMed] [Google Scholar]
- 15.LaPrade R.F., Johansen S., Agel J., Risberg M.A., Moksnes H., Engebretsen L. Outcomes of an anatomic posterolateral knee reconstruction. J Bone Joint Surg Am. 2010;92:16–22. doi: 10.2106/JBJS.I.00474. [DOI] [PubMed] [Google Scholar]
- 16.Ibrahim S.A., Ghafar S., Salah M. Surgical management of traumatic knee dislocation with posterolateral corner injury. Arthroscopy. 2013;29:733–741. doi: 10.1016/j.arthro.2012.11.021. [DOI] [PubMed] [Google Scholar]
- 17.Feeley B.T., Muller M.S., Sherman S., Allen A.A., Pearle A.D. Comparison of posterolateral corner reconstructions using computer-assisted navigation. Arthroscopy. 2010;26:1088–1095. doi: 10.1016/j.arthro.2009.12.014. [DOI] [PubMed] [Google Scholar]
- 18.Geeslin A.G., LaPrade R.F. Outcomes of treatment of acute grade-III isolated and combined posterolateral knee injuries: A prospective case series and surgical technique. J Bone Joint Surg Am. 2011;93:1672–1683. doi: 10.2106/JBJS.J.01639. [DOI] [PubMed] [Google Scholar]
- 19.Camarda L., Condello V., Madonna V., Cortese F., D'Arienzo M., Zorzi C. Results of isolated posterolateral corner reconstruction. J Orthop Traumatol. 2010;11:73–79. doi: 10.1007/s10195-010-0088-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Open technique for PLC reconstruction after multiligament knee injury in left knee.