High degree of consensus amongst an expert panel regarding focal resurfacing of chondral and osteochondral lesions of the femur with mini-implants.

INTRODUCTION: The rationale for the use of mini-implants for partial resurfacing in the treatment of femoral chondral and osteochondral lesions is still under debate. The evidence supporting best practise guidelines is based on studies with low-level evidence. A consensus group of experts was convened to collaboratively advance towards consensus opinions regarding the best available evidence. The purpose of this article is to report the resulting consensus statements. METHODS: Twenty-five experts participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted via an online survey of two rounds, for initial agreement and comments on the proposed statements. An in-person meeting between the panellists was organised during the 2022 ESSKA congress to further discuss and debate each of the statements. A final agreement was made via a final online survey a few days later. The strength of consensus was characterised as: consensus, 51-74% agreement; strong consensus, 75-99% agreement; unanimous, 100% agreement. RESULTS: Statements were developed in the fields of patient assessment and indications, surgical considerations and postoperative care. Between the 25 statements that were discussed by this working group, 18 achieved unanimous, whilst 7 strong consensus. CONCLUSION: The consensus statements, derived from experts in the field, represent guidelines to assist clinicians in decision-making for the appropriate use of mini-implants for partial resurfacing in the treatment of femoral chondral and osteochondral lesions. LEVEL OF EVIDENCE: Level V.

All-Polyethylene Tibial Component Does Not Affect Survivorship of Medial Unicompartmental Knee Arthroplasty at Mid-Term Follow-Up.

The present study's primary aim was to determine the survivorship of a large cohort of patients implanted with a single design all-polyethylene tibial component medial unicompartmental knee arthroplasty (UKA). Its secondary purpose was to investigate the reasons underlying implant failure, with specific attention to component positioning and limb alignment. Between 2007 and 2013, 166 patients underwent medial UKA with a single design all-polyethylene tibial component at two centers. Preoperatively and postoperatively, patients were administered clinical outcome scores and radiographic information were collected. Postoperative complications and causes of revision were recorded. A total of 140 patients (80 in Center A and 60 in Center B) who underwent all-polyethylene tibial component medial UKA (82 cases in Center A and 60 in Center B) were taken into account. Kaplan-Meier cumulative survivorship of implants was 96.5% (confidence interval [CI]: 91.7-98.6%) at an average follow-up of 61.1 months. Tibial aseptic loosening was accounted for failure in one case, while no correlation was found between implant positioning and failure. Two revisions were performed in Center A and three in Center B. Slight correction of the preoperative varus deformity was performed at both centers. All-polyethylene tibial component UKA provided satisfactory clinical and functional outcome, with excellent survival rate in the early and mid-term follow-up. Continued patient follow-up is needed to determine long-term survivorship of the examined UKA model.

Mid-Term Clinical Outcome and Reconstruction of Posterior Tibial Slope after UKA.

Unicompartmental knee arthroplasty (UKA) has gained growing popularity over the last decades. The posterior tibial slope (PTS) has been shown to play a significant role for knee biomechanics and is thought to be crucial for clinical function of the UKA. We evaluated the clinical outcome at mid-term follow-up after UKA. Furthermore, the reconstruction of the individual PTS was analyzed. A total of 91 consecutive patients undergoing medial UKA for osteoarthritis were included. Patients were contacted by telephone for a survival analysis at a minimum of 30 months after surgery. Patient-oriented questionnaires and Knee Osteoarthritis Outcome Score (KOOS) were obtained. A retrospective chart review and radiological analysis of component alignment were performed for all patients before and at 6 weeks after surgery. Of 91 patients (93 knees) undergoing UKA, 69 patients (70 knees) were available for clinical follow-up after a mean of 56.0 (range 31-81) months post-surgery. The clinical results of the examined patients in the present study showed mean subscale scores of the KOOS and Western Ontario and McMaster Universities Osteoarthritis Index between 71 and 91%. Overall 7 of 91 patients were revised during the course of follow-up period and underwent total knee arthroplasty. A Kaplan-Meier analysis showed a survival rate for UKA of 90.5% after 48 months. Calculated implant survival was 75.9 months (95% confidence interval 72.3-79.6) at the mean. The radiographic analysis of pre- and postoperative PTS showed no differences (p = 0.113).UKA for osteoarthritis of the medial knee compartment shows encouraging clinical results at mid-term follow-up. The individual PTS could be reconstructed within acceptable ranges. This is a retrospective therapeutic study with Level IV.

Kinematics of monoblock bicompartmental knee arthroplasty during weight-bearing activities.

PURPOSE: There is an increased interest in treating arthritis of the medial and patellofemoral compartments without using a total knee arthroplasty. The purpose of this study was to measure kinematics in knees with a monoblock bicompartmental arthroplasty to see whether maintaining the cruciate ligaments and lateral compartment resulted in consistent kinematics more similar to healthy knees than those observed in replaced knees. METHODS: The kinematics of ten knees with monoblock bicompartmental arthroplasty were observed using fluoroscopy during three weight-bearing activities. Model-image registration techniques were used to quantify the three-dimensional motions of the knee joints. RESULTS: During kneeling, lunging, and stair-step activities, the medial condyle remained relatively close to the centre of the tibial plateau, while the lateral condyle typically moved posteriorly with flexion. Knees generally exhibited motion patterns consistent with retained cruciate ligament function, but individual patterns varied significantly. CONCLUSIONS: Bicompartmental knee arthroplasty has the potential to retain more natural knee function. Improved tools for aligning the implants and increased implant sizing options may be required to achieve highly consistent results and realize the clinical benefit of a knee arthroplasty with intact cruciate ligaments. LEVEL OF EVIDENCE: III.

Bicompartmental knee arthroplasty: a bone-sparing, ligament-sparing, and minimally invasive alternative for active patients.

In the past, treatment of knee osteoarthritis has been limited to unicompartmental knee replacement or total knee arthroplasty (TKA). Neither option is well suited for the active patient with midstage osteoarthritis of the medial and patellofemoral compartments. Now an alternative treatment is available that targets the diseased area without sacrifice of normal bone or both the cruciate ligaments. Minimally invasive surgical techniques are easily used, which reduces tissue trauma and results in a quicker recovery than TKA. Bicompartmental replacement offers decreased pain, stability through normal ligament structure, and the retention of normal bone for patients with medial and patellofemoral osteoarthritis.