Bohler’s angle’s role in assessing the injury severity and functional outcome of internal fixation for displaced intra-articular calcaneal fractures: a retrospective study

Abstract

BackgroundControversy exits over the role of Böhler’s angle in assessing the injury severity of displaced intra-articular calcaneal fractures and predicting the functional outcome following internal fixation. This study aims to investigate whether a correlation exists between Böhler’s angle and the injury severity of displaced calcaneal fractures, and between surgical improvement of Böhler’s angle and functional outcome.MethodsPatients treated operatively for unilateral closed displaced intra-articular calcaneal fractures from January 1, 2004 to March 31, 2008 were identified. The Böhler’s angles of both calcaneus were measured, and the measurement of the uninjured foot was used as its normal control. The difference in the value of Böhler’s angle measured preoperatively or postoperatively between the angle of the injured foot and that of the contralateral calcaneus were calculated, respectively. The change in Böhler’s angle by ratio was calculated by dividing the difference value of Böhler’s angle between bilateral calcaneus by its normal control. The injury severity was assessed according to Sanders classification. The functional outcomes were assessed using American Orthopaedic Foot & Ankle Society hindfoot scores.Results274 patients were included into the study with a mean follow-up duration of 71 months. According to Sanders classification, the fracture pattern included 105 type II, 121 type III and 48 type IV fractures. According to American Orthopaedic Foot & Ankle Society hindfoot scoring system, the excellent, good, fair and poor results were achieved in 104, 132, 27, and 11 patients, respectively. The preoperative Böhler’s angle, difference value of Böhler’s angle between bilateral calcaneus, and change in Böhler’s angle by ratio each has a significant correlation with Sanders classification (rs=−0.178, P=0.003; rs=−0.174, P=0.004; rs=−0.172, P=0.005, respectively), however, is not correlated with functional outcome individually. The three postoperative measurements were all found to have a significant correlation with American Orthopaedic Foot & Ankle Society hindfoot scores (rs=0.223, P<0.001; rs=0.224, P<0.001; rs=0.220, P<0.001, respectively). However, these correlations were all weak to low.ConclusionsThere was a significant correlation between preoperative Böhler’s angle and the injury severity of displaced intra-articular calcaneal fractures, but only postoperative Böhler’s angle parameters were found to have a significant correlation with the functional recovery.

Long-term Results of Operative Treatment of Calcaneal Fractures

“…Opinions vary as to which one of these features is of key importance in the treatment. Makki, Su, and Isaacs conducted three independent studies and found that it is the postoperative Böhler's angle that allows for pre dicting a good functional result [36][37][38]. The analysis of our study results has led us to similar conclusions.…”

“…Zda nia są po dzielo ne. Mak ki, Su oraz Isa acs, w trzech nie za le żnych ba da niach, do szli do wnio sku, że to po ope ra cyj na war tość ką ta Böhle ra pro gno zu je do bry wy nik funkcjo nal ny [36][37][38]. Ana li zu jąc wy ni ki ba da nej gru py treated with open reduction and internal fixation with a plate and screws, we achieved 16 excellent (35.5%) and 10 good (22.6%) results.…”

Association of pre-treatment radiographic characteristics of calcaneal fractures on patient-reported outcomes

“…In addition, a negative Böhler's angle, a negative calcaneal compression angle, or a fracture into the anterior surface of the calcaneus is associated with worse patient outcomes. The literature reports contrasting results in the predictive value of the Böhler's angle [11][12][13]36]. The studies from Loucks et al (1999) and Persson et al (2015) demonstrated that a negative Böhler's angle in patients with an intra-articular calcaneal fracture is negatively related to health-related quality of life outcome [11,12].…”

Predicting loss of height in surgically treated displaced intra-articular fractures of the calcaneus

“…However, the subtalar joint frequently collapses (calcaneal collapse) post-operatively to some extent, which can be seen at radiological follow-up [11,14,24]. Several authors noted a correlation between initial BA and outcome [3,10,15,18,22,24]. The BA at time of admission appears to be a valuable prognosticator for functional longterm results [18].…”