Unicompartmental Knee Replacement Combined to Anterior Cruciate Ligament Reconstruction: Midterm Results

Abstract

A study was conducted to retrospectively evaluate the outcomes of combined medial unicompartmental knee replacement (UKR) and anterior cruciate ligament (ACL) reconstruction. The hypothesis was that this procedure would lead to satisfying results in patients affected by medial osteoarthritis and ACL insufficiency. Fourteen patients with ACL deficiency and concomitant medial compartment symptomatic osteoarthritis were treated from 2006 to 2010. Twelve of them were followed-up for an average time of 7.8 year (range: 6–10 years). Assessment included Knee Osteoarthritis Outcome score (KOOS), Oxford Knee score (OKS), American Knee Society scores (AKSS), Western Ontario and McMaster (WOMAC) index of osteoarthritis, Tegner's activity level, objective examination including instrumented laxity test with KT-1000 arthrometer, and standard X-rays. KOOS score, OKS, WOMAC index, and the AKSS improved significantly at follow-up (p < 0.001). There was no clinical evidence of instability in any of the knees as evaluated with clinical and instrumented laxity testing (p < 0.001). No pathologic radiolucent lines were observed around the components. In one patient, a total knee prosthesis was implanted due to the progression of signs of osteoarthritis in the lateral compartment 3 years after primary surgery. UKR combined with ACL reconstruction is an effective therapeutic option for the treatment of combined medial unicompartmental knee osteoarthritis and ACL deficiency and confirms subjective and objective clinical improvement up to 8 years after surgery. This study reflects level IV evidence.

Results of Simultaneous Unicompartmental Knee Arthroplasty and Anterior Cruciate Ligament Reconstruction: A Systematic Review

“…Of the seven included studies, two were prospective [ 17 , 18 ] and four were retrospective [ 19 , 20 , 21 , 22 ] of level of evidence (LOE) IV. One was a retrospective cohort study with comparison group of LOE III [ 23 ].…”

“…The overall number of combined procedures amounted to 169, with 169 patients involved. Within the included studies, the number of subjects varied from 8 [ 20 ] to 58 [ 17 ], with a mean age ranging from 44 [ 19 ] to 54 [ 21 ] years. The average follow-up was 6.3 years, ranging from 3.8 [ 22 ] to 14.6 [ 20 ] years.…”

“…The primary complaints of all the patients were knee instability and pain referred at the medial compartment. Some authors highlighted that patients with a higher grade of OA (Ahlbäck’s type 3 and 4) complained of [ 15 , 19 , 20 , 22 ] pain as the most debilitating symptom, while instability was predominant in subjects with a lower degree of articular degeneration (Ahlbäck’s type 2) [ 21 ].…”

“…Manual laxity tests were performed to evaluate the ACL insufficiency. The diagnosis was verified by magnetic resonance image (MRI) in three studies [ 21 , 22 , 23 ], whereas other authors did not use it as a standard preoperative diagnostic tool [ 18 , 19 , 20 ].…”

Biomechanical effect of tibial slope on the stability of medial unicompartmental knee arthroplasty in posterior cruciate ligament-deficient knees

“… 16 During mid-flexion, the ACL and PCL provide knee joint stability, and during high flexion the PCL is responsible for posterior femoral rollback. 16 - 18 Ventura et al 19 showed that UKA combined with ACL reconstruction is an effective therapeutic option for the treatment of combined medial unicompartmental knee OA and ACL deficiency, and confirms subjective and objective clinical improvement up to eight years after surgery. However, long-term results suggest that an insufficient PCL may promote the development of OA in knee joints due to excessive displacements between the tibia and femur.…”