Large Versus Small Opening Wedge High Tibial Osteotomies Performed With a Protective Wire Over the Lateral Hinge: Incidence of Lateral Hinge Fracture and Early Clinical Outcomes

High tibial osteotomy versus unicompartmental knee arthroplasty in advanced medial compartmental knee arthrosis: A comparative study with propensity score matched analysis

BACKGROUND

Isolated knee medial compartmental osteoarthritis(MOA) can be treated with High Tibial Osteotomy (HTO) or Unicompartmental Knee Arthroplasty (UKA). This study aims to describe and compare outcomes of HTO and UKA in patients with isolated severe MOA. The authors hypothesized that similar outcomes can be achieved.

METHODS

Data was collected prospectively of HTOs and UKAs performed between January-2016 and April-2021 by a knee surgeon. Oxford Knee Score (OKS), Knee Society Knee Score (KSKS) and Function Score (KSFS) were collected pre-operatively, six-months and two-years post-surgery. OA severity was graded on pre-operative radiograph. Medial Proximal Tibia Angle (MPTA), Lateral Distal Femoral Angle (LDFA), Joint Line Convergence Angle (JLCA) and Hip-Knee-Ankle Angle (HKAA), were measured on full-length radiograph. 47 HTO and 74 UKA were included. Propensity score matching was performed, accounting for preoperative scores, age, gender and body mass index (BMI), before statistical analysis. Level of significance was set at 0.05.

RESULTS

Both groups were similar in age(56.42 vs 58.57, p = 0.067), BMI(29.82 vs 29.09, p = 0.484), gender distribution (p = 0.663) and laterality (p = 0.836). Pre-operatively, both groups were similar in clinical scores and lower limb alignment. On follow-up, both groups achieved similar improvements in clinical scores. However, the HTO group reported poorer extension at 6-months (7.91° vs 4.80°, p = 0.013) and 2-years (5.57° vs 3.24°, p = 0.018). Three cases of hinge fracture and six cases of implant removal occurred in the HTO group. One case of tibial fracture occurred in the UKA group.

CONCLUSIONS

In severe MOA, similar outcomes were achieved with HTO and UKA at two years.

A systematic approach to managing complications after proximal tibial osteotomies of the knee

Proximal tibial osteotomy (PTO) is an effective procedure for active and young adult patients with symptomatic unicompartmental osteoarthritis and malalignment. They were considered technically demanding and prone to various complications related to the surgical technique, biomechanical or biological origin. Among the most important are hinge fractures and delayed or non-healing, neurovascular complications, loss of correction, implant-related problems, patellofemoral complaints, biological complications and changes in limb length. Being aware of these problems can help minimizing their prevalence and improve the results of the procedure.The aim of this narrative review is to discuss the potential complications that may occur during and after proximal tibial osteotomies, their origin and ways to prevent them.