From the Guidelines
Clinical misdiagnosis of nonunion after a Lapidus procedure is estimated to occur in around 5-10% of cases, as some patients with radiographic "nonunion" are actually asymptomatic and have achieved clinical union with fibrous tissue. This estimate is based on the fact that around 5-10% of bone fractures experience delayed healing or non-union of the fracture, as reported in a clinical practice guideline published in the BMJ in 2017 1. The primary reason for misdiagnosis is that radiographic assessment often fails to accurately represent the true healing status of the fusion site.
- Key factors contributing to misdiagnosis include:
- Normal postoperative pain that may persist for 3-6 months
- Hardware-related discomfort that mimics nonunion symptoms
- Adjacent joint arthritis that develops after fusion
- For accurate diagnosis, clinicians should correlate clinical symptoms with imaging findings, specifically looking for pain directly at the fusion site with manipulation, progressive deformity, or hardware failure.
- Weight-bearing CT scans, as mentioned in the context of bone healing 1, provide the most reliable assessment when nonunion is suspected, as they are significantly more accurate than plain radiographs for evaluating fusion.
From the Research
Clinical Misdiagnosis of Nonunion after Lapidus Procedure
- The frequency of nonunion after a Lapidus procedure varies across studies, with reported rates ranging from 2.7% to 8.3% 2, 3.
- A study published in 2015 found a union rate of 97.3% in 182 feet that underwent the modified Lapidus procedure, indicating a nonunion rate of 2.7% 2.
- Another study from 2014 reported a nonunion rate of 8.3% in 36 feet that underwent Lapidus arthrodesis using staple fixation 3.
- A 2022 study identified risk factors for nonunion associated with the modified Lapidus procedure, including previous bunionectomy, increased body mass index, and preoperative HV angle 4.
- However, there is limited information available on the clinical misdiagnosis of nonunion after a Lapidus procedure, and the provided studies do not directly address this topic.
- Studies on diagnostic errors and misdiagnosis-related harms in general medical practice suggest that vascular events, infections, and cancers are the most common causes of serious misdiagnosis-related harms 5, 6.
- While these studies do not specifically address the Lapidus procedure or nonunion, they highlight the importance of accurate diagnosis and the potential consequences of misdiagnosis in various medical contexts.