Relative Risk of Different Operations for Medial Compartment Osteoarthritis of the Knee

Abstract

The relative risk of total knee arthroplasty (TKA), high tibial osteotomy (HTO), and medial unicompartment (UKA) replacement for medial compartment arthritis is presented. Risk is defined as the product of the probability of an event occurring and its consequence. To define consequence, 2 related scales of impact (1 systemic and 1 local) are suggested. The probability of a complication is derived from the incidence as found in the published literature and expressed as a decimal of 1. The cumulative risk is expressed as the sum of the risks of all individual complications. The overall impact of specific comorbidities has been calculated when their influence on the incidence of a particular complication is known. Of the 3 operations, TKA has the highest cumulative risk of systemic complications and HTO is the most likely to produce local technical problems. UKA is the safest of the procedures. The relative risk of TKA:HTO:UKA is 1.00:1.01:0.31. For TKA, the greatest additional risk is morbid obesity, which increases overall risk by 31% by virtue of a 7.8-fold increase in infection rate. Cardiorespiratory disease, diabetes mellitus, smoking, and cirrhosis of the liver increase cumulative risk by 20%, 17%, and 17%, respectively.The authors conclude that a quantitative assessment of operative risk is possible and useful. However, it depends on the availability of reliable complication incidence data.

Outcome of unicompartmental knee arthroplasty in octogenarians with tricompartmental osteoarthritis: A longer followup of previously published report

“…Traditionally reserved for nonobese, less active, young patients with advanced noninflammatory UCOA,13 the UKA procedure has (within these indications) demonstrated good success in function and longevity 111629. However, patients with marginal other compartment involvement and ACL incompetence have shown matched good results in the short term as well 93031.…”

“…), or surgeon-related (improper technique, partial injury to cruciate ligaments or unresurfaced tibiofemoral articular cartilage, failure to treat the underlying pathology producing the UCOA, etc.) issues 31015. More recently, however, Seyler et al 30.…”

“…Surgical treatment of advanced UCOA (with functionally intact ligaments) is possible with corrective femoral or tibial osteotomy (lateral closed wedge, medial open wedge, and/or modifications thereof), and has shown success when judiciously selected 23. An apt alternative in properly selected younger patients is the unicompartmental knee arthroplasty234 (UKA).…”

“…An apt alternative in properly selected younger patients is the unicompartmental knee arthroplasty234 (UKA). UKA functions primarily by recreating joint space in the compartment that has collapsed, and partially realigning the mechanical axis.…”

“…UKA functions primarily by recreating joint space in the compartment that has collapsed, and partially realigning the mechanical axis. In both high tibial osteotomy (HTO) and UKA, the cruciate ligaments and extensor mechanism are left intact, providing for near-normal knee kinematics 35. Literature review shows slightly better results for UKA in terms of survivorship and functional outcome, compared to HTO 26.…”