Management of Medial Femorotibial Knee Osteoarthritis in Conjunction with Anterior Cruciate Ligament Deficiency: Technical Note and Literature Review

Abstract

In recent years, there has been increased interest in the management of medial femorotibial knee osteoarthritis (OA) in conjunction with anterior cruciate ligament (ACL) deficiency. Traditional treatment modalities included conservative therapy, high tibial osteotomy with or without ACL reconstruction, and total knee replacement. Since younger patients with higher physical demands are more likely to suffer from this pathological condition, reduced invasiveness, faster recovery time, and improved knee kinematics are preferred to allow for satisfying clinical and functional outcomes. Thus, a new surgical strategy combining medial unicompartmental knee replacement (UKR) and ACL reconstruction has been proposed to allow bone stock preservation, to reduce surgical morbidity and recovery time, and ultimately to improve joint kinematics and clinical outcomes. Based on the data present in the literature, in the setting of unicompartmental OA in association with ACL deficiency, UKR combined with ACL reconstruction provided encouraging early results. Studies evaluating the outcomes of combined ACL reconstruction and UKR demonstrate promising results in select patient populations. Improved knee stability, pain relief, functional recovery, and patient satisfaction improved after surgery. Moreover, the combined approach offered advantages such as reduced surgical trauma, faster rehabilitation, and preservation of native knee anatomy compared with traditional treatment strategies. However, still, high-level studies on this topic are lacking; therefore, more comparative studies reporting long-term outcomes are needed to support the potential of this combined procedure to become mainstream. In this paper, we discuss the relevant features and rationale behind the indications and technique of this combined surgical procedure, to help surgeons choose the correct therapeutic approach for a patient with concomitant medial OA and ACL insufficiency. Continued advancements in surgical techniques, patient selection criteria, and rehabilitation strategies will further enhance the success of this combined approach, offering hope to individuals with concomitant ACL injuries and unicompartmental knee OA.

Keywords: ACL reconstruction; anterior cruciate ligament; knee; medial osteoarthritis; unicompartmental knee arthroplasty; unicompartmental knee replacement.

Figure 1

Preoperative assessment demonstrating isolated medial knee osteoarthritis secondary to ACL incompetency.

Figure 2

Stripping of autologous semitendinosus and gracilis tendon grafts through a minimally invasive incision over the pes anserinus.

Figure 3

Reaming of the tibial tunnel based on graft size slightly more laterally than usual, close to the tibial tubercle. This avoids weakening of the tibial medial plateau and/or impingement on the tibial component with the late distal graft insertion.

Figure 4

A new minimally invasive, vertical incision is performed proximally, medially to the patellar tendon to allow arthroplasty implantation.

Figure 5

Impactor placement filling the tibial tunnel to avoid accidental penetration of the cement into the tunnel before implantation of the components.

Figure 6

Graft fixation is performed at the end of the surgical procedure, in order to prevent the knee valgus effect on the length of the ACL. Proximal fixation is achieved with an adjustable loop button and distal fixation with a bioabsorbable interference screw.