Stiffness after unicompartmental knee arthroplasty: Risk factors and arthroscopic treatment

Abstract

Introduction: One of the principal complications after total knee arthroplasty (TKA) is stiffness. There are no publications concerning stiffness after unicompartmental knee arthroplasty (UKA). Study objectives were to describe the incidence of stiffness after UKA, to look for risk factors, and to describe safe and effective arthroscopic treatment. Methods: There were 240 UKA performed between March 2016 and January 2019 included. Robotic-assisted surgery was performed in 164 patients and mechanical instrumentation in 76 patients. Stiffness was defined as flexion < 90° or a flexion contracture > 10° during the first 45 post-operative days. Patients with stiffness were treated with arthroscopic arthrolysis. Several factors were studied to look for risk factors of stiffness: body mass index, gender, age, mechanical or robotic instrumentation, preoperative flexion, previous meniscectomy, and anticoagulant treatment. Arthrolysis effectiveness was evaluated by flexion improvement and UKA revision rate. Results: 22 patients (9%) developed stiffness. Mechanical instrumentation significantly increased the risk of stiffness with OR = 0.26 and p = 0.005. Robotic-assisted surgery decreased the risk of stiffness by five-fold. Before arthrolysis, mean knee flexion was 79°, versus 121° (53% improvement) after arthroscopic arthrolysis. Only 2 patients (9%) underwent UKA revision after arthrolysis. Discussion: Stiffness after UKA is an important complication with an incidence of 9% in this study. Arthroscopic arthrolysis is a safe and effective treatment with a range of motion improvement of > 50%. Robotic-assisted surgery significantly decreases the risk of postoperative stiffness. Level of evidence: Level III, therapeutic study, retrospective cohort study

Combined procedures with unicompartmental knee arthroplasty: High risk of stiffness but promising concept in selected indications

“…Fournier et al . [ 22 ] reported a high rate of stiffness after isolated UKA with a good result of arthroscopic arthrolysis to treat this complication similar to our results. Each procedure (ACL reconstruction, HTO, UKA, PFP) could potentially be complicated with postoperative stiffness.…”

Risk Factors for Postoperative Knee Stiffness in Patients with Anteromedial Knee Osteoarthritis Undergoing Unicompartmental Knee Arthroplasty with Cemented Prostheses: A Short-Term, Retrospective, Case-Control Study

“…Different cohorts have different incidences of stiffness in these types of knee joints. According to Fournier et al, the prevalence of stiffness treated with UKA was 9% at the 1-year follow-up [ 7 ]. Hurst et al revealed that 12% of patients experienced stiffness in their knee joints, which subsequently led to treatment failures [ 8 ].…”

“…Stiff knees can cause pain and limited function during daily activities, particularly when ascending or descending stairs, sitting or standing up, and tying shoelaces [ 9 ]. Meanwhile, more complex surgical procedures, such as surgical dissolution of scar tissue (arthroscopic or open surgery) or revision arthroplasty, are required in some recalcitrant cases to relieve pain and restore knee function [ 7 ]. We reviewed many studies.…”

“…Knee stiffness can be disabling and is among the most common causes of patient dissatisfaction following UKA. The treatment of stiffness can range from aggressive physical therapy to revision arthroplasty [ 7 , 10 – 14 ]. Therefore, knowing how to reduce the incidence of knee stiffness after UKA has become crucial.…”

“…Robotic-assisted surgery was performed in 164 patients and mechanical instrumentation in 76 patients. They demonstrated that stiffness after UKA is correlated with mechanical instrumentation as a risk factor [ 7 ]. Researchers such as Saito et al have argued that inserting a component that is too thick into a narrow space can result in joint stiffness.…”