Surgical Management of Concomitant Proximal Tibiofibular Instability and Medial Collateral Ligament Tear: A Case Report

Abstract

Introduction: Proximal tibiofibular instability is a relatively rare cause of lateral-sided knee pain, and it can be difficult to diagnose. However, medial collateral ligament (MCL) tears are much more common and are much easier to diagnose. Concomitant management of these injuries, however, is uncommon and not well described.

Case report: We present the case of a 26-year-old female who was struck on the lateral side of the knee by a motor vehicle. She suffered a Grade III MCL tear involving both the superficial and deep bands of the ligament, as well as proximal tibiofibular instability. She failed a course of non-operative management with bracing, and the decision was made to proceed with surgery. The procedure entailed peroneal nerve neurolysis, proximal tibiofibular joint stabilization with Tight Rope™ construct, deep MCL repair, and the superficial MCL reconstruction.

Conclusion: A heightened suspicion for proximal tibiofibular instability must be had in patients with trauma to the knee and lateral-sided pain. In this case, concurrent MCL reconstruction and proximal tibiofibular joint stabilization were necessary to return the knee to normal kinematics.

Keywords: Proximal tibiofibular instability; knee; medial collateral ligament tear.

Figure 1

Presenting left knee X-rays and magnetic resonance imaging coronal views. (a) Anterior posterior X-ray with medial fleck along joint line. (b) Lateral X-ray. (c) Medial collateral ligament disruption including capsular avulsion.(d) Edema around the proximal tibiofibular joint as seen in both tibia and fibula at the joint.

Figure 2

Intraoperative stress radiography showing gross medial opening in full extension to valgus stress. Fleck of bone also seen from capsular avulsion of deep medial collateral ligament tissue.

Figure 3

Left knee surgical sequence. (a) Medial (longer incision) and lateral planned incisions. (b) Decompressed peroneal nerve (scissor pointing at nerve), *indicates biceps femoris tendon near attachment to fibular head. (c) Superficial (clamp) and deep (forceps) medial collateral ligament (MCL) tissue damage. (d) Deep MCL repair. Circle indicates sutures from suture anchor in distal femur. Other sutures are free sutures as part of deep repair.

Figure 4

(a) Tibial sided button from proximal tibiofibular joint stabilization sitting just proximal to the pes anserine tendons. (b) Fully reconstructed superficial medial collateral ligament (MCL) reconstruction with Achilles tendon allograft. The distalization of fixation with the staple (circle) >6 cm distal to joint line is to avoid pes anserine with large graft. The square indicates sutures from the proximal tibial fixation for the MCL at approximately 1 cm distal to the joint line.

Figure 5

Intraoperative anterior posterior (a) and lateral (b) after proximal tibiofibular joint stabilization and medial collateral ligament (MCL) reconstruction. Note the posterior to anterior nature of the tightrope on the lateral view. The white circle indicates deep MCL repair anchor just proximal to the joint line.

Figure 6

Two weeks post-operative anterior posterior radiographs comparing both sides. Proximal tibiofibular Tightrope™ buttons and tibial staple for medial collateral ligament reconstruction well visualized.

Figure 7

Left knee X-rays before surgery no stress (a), intraoperative with stress (b), and post-fixation no stress, but with fixation for proximal tibiofibular joint instability and medial collateral ligament reconstruction (c).