ACL reconstruction with unicondylar replacement in knee with functional instability and osteoarthritis

Abstract

Severe symptomatic osteoarthritis in young and active patients with pre-existing deficiency of the anterior cruciate ligament and severe functionally instability is a difficult subgroup to manage. There is considerable debate regarding management of young patients with isolated unicompartment osteoarthritis and concomitant ACL deficiency. A retrospective analysis of was done in 9 patients with symptomatic osteoarthritis with ACL deficiencies and functional instability that were treated with unicompartment knee arthroplasty and ACL reconstruction between April 2002 and June 2005. The average arc of flexion was 119° (range 85° to 135°) preoperatively and 125° (range 105° to 140°). There were no signs of instability during the follow up of patients. No patients in this group were reoperated. In this small series we have shown that instability can be corrected and pain relieved by this combined procedure.

ACL-deficient knee and unicompartmental OA: state of the art

“…The reason for most of the failures was related to eccentric or increased loading of the tibial plateau that leads to tibial loosening and UKA failure. More encouraging results after combined medial UKA and ACL reconstruction in a single surgical step were reported by Tinius et al ,61 Krishnan et al ,11 and Tian et al, 68 Krishnan et al 11 and Tian et al 68 noted no signs of instability and no need for reoperation during the follow-up. Tinius et al 61 reported improvement in Knee Society Scores and anterior translation of the tibia as compared with preoperative data without any complications at 53 months of follow-up.…”

“…In the last century, surgeons11 52 used a bone-patellar tendon-bone (BPTB) graft, while others23 61 68 preferred to use hamstrings. Krishnan et al 11 claim that a BPTB graft offers the advantage that it can be harvested through the same UKA incision and thus reduce surgical morbidity but this graft might create a patella baja, which is biomechanically less favourable for the extensor mechanism. After the graft is harvested with a tendon stripper, or a saw in BPTB, the harvested tendon is looped to create a four-stranded graft or adapted to the tunnel diameter in case of BPTB.…”

“…The tibial tunnel is created with an outside-in technique using a standard tibial guide set at an angle between 50° and 55°23 in the horizontal plane on the tibial plateau; it is important to position the tunnel slightly lateral or just next to the tuberosity in order to prevent medial tibial plateau fracture and impingement on the tibial component of a UKA 11…”

“…While Ventura et al 23 and Kirshnan et al 11 prefer brace-free postoperative rehabilitation, other authors place the operated knee in a dynamic brace set between 0° and 90°. Patients are able to walk with physiotherapist supervision and the aid of crutches and protected weight-bearing on the first postoperative day.…”

“…The problems arising from functional ACL insufficiency or its complete absence are related to movement of the central pivot and sidestepping during which joint failure can limit sports activity and restrict activities of daily living 10. Knee joint instability due to ACL insufficiency produces various degenerative changes to the joint, including intra-articular damage, meniscal tears and varus morphology, leading to gradual thinning of the cartilage and resulting in posteromedial OA, which can be appreciated on weight-bearing knee radiographs 11. The incidence of OA onset in patients with ACL tears varies widely from 24%12 to 86% 13…”