The Baker Classification for Capsular Contracture in Breast Implant Surgery Is Unreliable as a Diagnostic Tool

Abstract

Background: Breast implants are frequently used in cosmetic and reconstructive breast surgery. Capsular contracture, the most common long-term complication, is usually graded using the Baker classification. Despite its widespread use, the reliability of the Baker classification has never been established. The aim of this study was to determine the interobserver reliability and agreement of the Baker classification. Methods: Sixty women who had undergone cosmetic breast augmentation were included. They were examined independently by two plastic surgeons from an observer pool. The Baker score was determined, along with firmness, dislocation, symmetry, and pain using four-point scales. Patients were asked to complete the BREAST-Q postaugmentation module. The interobserver reliability and agreement were calculated for all variables with a quadratic weighted kappa. Results: The interobserver reliability of the Baker classification was poor (kappa, 0.55; 95 percent CI, 0.37 to 0.72). Interobserver reliability of the clinical parameters firmness (0.64; 95 percent CI, 0.49 to 0.79), dislocation (0.49; 95 percent CI, 0.26 to 0.73), and symmetry (0.61; 95 percent CI, 0.34 to 0.88) was also poor. Pain scores seemed more reliable (0.72; 95 percent CI, 0.56 to 0.89); however, most patients had no pain. The interobserver agreement for the Baker score was 48 percent; in 43 percent, the observers differed one category; and in 12 percent, the difference was more than one category. Conclusions: Interobserver reliability and observer agreement of the Baker classification for capsular contracture were poor. Consensus about how to adequately rate the symptoms of capsular complaints is lacking. A more reliable method of measurement or description is needed, especially for scientific research purposes, to assess the long-term problems associated with breast implants. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.

SEM and TEM for identification of capsular fibrosis and cellular behavior around breast implants – a descriptive analysis

“…In fact, studies report a prevalence of CF of 2.8 to 20.4% [2][3][4][5][6][7][8]. The degree of severity is clinically classified by the Baker score system which includes four stages [9,10]. The first stage is the least severe and is characterized by a lack of clinical symptoms, while the fourth stage represents the most severe form of CF characterized by breast deformity, stiffness, and pain.…”

Current Concepts in Capsular Contracture: Pathophysiology, Prevention, and Management

“…To help objectify and grade the severity, both the Baker and then Baker-Spear classifications were created. 48,49 Baker Classification Augmentation…”

“…The grading systems mentioned above have sparked some controversy, especially in the reconstructive literature due to the fact that no validation studies have been performed. 48 One study which utilized two independent plastic surgeons found that the interobserver reliability of the Baker grading scale is quite poor. 48 This is likely due to the broad spectrum of clinical presentations associated with each strata of the classification.…”

Breast softness in patients randomised to postmastectomy breast reconstruction with an expander prosthesis or DIEP flap

“…A limitation is that no interobserver agreement was tested for the objective examinations. A recently published study reported low interobserver agreement for grading capsular contracture according to the Baker scale, emphasising the importance of this matter [17]. In order to strengthen the role of applanation tonometry as an objective breast softness measurement tool, an assessment of the interobserver agreement is warranted.…”

“…It is a four-grade scale and grades III-IV correspond to a symptomatic hard breast defined as showing capsular contracture [16]. The Baker scale is based on a combination of clinical palpation and breast appearance and is thus dependent on the examiner's experience and subjective assessment [17].…”