Abstract
Purpose
Exclusion or detection of non-displaced radial head fractures can be difficult in radiographs, because they might lack conclusive radiographic signs, such as fracture lines or distracted articular fragments. Based on the typical injury mechanism of a radial head fracture, causing the head to hit the capitulum and leading to a depression of the anterolateral border of the radial head, we hypothesized that even slight cortical irregularities in the transition zone of the radial neck and head result from that depression and may be a reliable radiographic sign of an underlying radial head fracture. Secondarily, we tested the null hypothesis that the lack of cortical irregularities is sufficient to exclude a fracture of the radial head.
Methods
84 patients with sets of anteroposterior and lateral radiographs of the elbow were identified from the database of a level 1 trauma center and divided into 2 groups. Group A was formed out of 42 patients with non-displaced radial head fractures, group B out of 42 patients without a history of previous elbow trauma, whose medical history also contained radiographic images. After the radial head was blackened, the transition zone of the radial neck and head was assessed by two attending orthopedic surgeons for presence of a cortical irregularity. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of cortical irregularity were calculated for the assessment of radial head fractures. The kappa measure of agreement was utilized to evaluate interrater agreement.
Results
The specificity was 87.80 and 97.56 %, respectively, its sensitivity 86.04 and 75.61 %. A high NPV (85.71 %; 80.00 %) and PPV (96.88 %; 88.10 %.) were observed. The interrater agreement for the proposed diagnostic method was high, with a Cohen kappa score of 0.737 (p < 0.001).
Conclusions
A cortical irregularity in the transition zone of the radial neck and head seems to be a reliable radiographic sign of an underlying radial head fracture. The absence of the cortical irregularity can be used to correctly identify a non-fractured radial head.
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References
Burkhart KJ, Wegmann K, Muller LP, Gohlke FE (2015) Fractures of the radial head. Hand Clin 31(4):533–546
Burkhart KJ, Wegmann K, Dargel J, Ries C, Mueller LP (2012) Treatment of radial head and neck fractures: in favor of anatomical reconstruction. Eur J Trauma Emerg Surg 38(6):593–603
Ruchelsman DE, Christoforou D, Jupiter JB (2013) Fractures of the radial head and neck. J Bone Joint Surg Am 95(5):469–478
Mason ML (1954) Some observations on fractures of the head of the radius with a review of one hundred cases. Br J Surg 42(172):123–132
Dillon MT, Getz CL, Beredjiklian PK, Wiesel BB, Carolan GF, Ramsey ML (2010) Evaluation of reliability of the Mason classification for radial head fractures. Am J Orthop (Belle Mead NJ) 39(9):430–432
Johnston GW (1962) A follow-up of one hundred cases of fracture of the head of the radius with a review of the literature. Ulster Med J 31:51–56
van Riet RP, Morrey BF (2008) Documentation of associated injuries occurring with radial head fracture. Clin Orthop Relat Res 466(1):130–134
Kaas L, Turkenburg JL, van Riet RP, Vroemen JP, Eygendaal D (2010) Magnetic resonance imaging findings in 46 elbows with a radial head fracture. Acta Orthop 81(3):373–376
Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C (2005) Radial head fractures: MRI evaluation of associated injuries. J Shoulder Elbow Surg 14(4):421–424
Burkhart KJ, Franke S, Wegmann K, Ries C, Dehlinger F, Muller LP, Hollinger B (2015) Mason I fracture—a simple injury? Unfallchirurg 118(1):9–17
Greenspan A, Norman A (1982) The radial head, capitellum view: useful technique in elbow trauma. AJR Am J Roentgenol 138(6):1186–1188
Jarraya M, Hayashi D, Roemer FW, Crema MD, Diaz L, Conlin J, Marra MD, Jomaah N, Guermazi A (2013) Radiographically occult and subtle fractures: a pictorial review. Radiol Res Pract 2013:370169
de Beaux AC, Beattie T, Gilbert F (1992) Elbow fat pad sign: implications for clinical management. J R Coll Surg Edinb 37(3):205–206
Goswami GK (2002) The fat pad sign. Radiology 222(2):419–420
O’Dwyer H, O’Sullivan P, Fitzgerald D, Lee MJ, McGrath F, Logan PM (2004) The fat pad sign following elbow trauma in adults: its usefulness and reliability in suspecting occult fracture. J Comput Assist Tomogr 28(4):562–565
Bohrer SP (1970) The fat pad sign following elbow trauma. Its usefulness and reliability in suspecting “invisible” fractures. Clin Radiol 21(1):90–94
Jie KE, van Dam LF, Hammacher ER (2015) Isolated fat pad sign in acute elbow injury: is it clinically relevant? Eur J Emerg Med 23(3):228–231
Swischuk LE (2001) The posterior fat pad sign and use of comparison radiographs in the diagnosis of occult fractures. J Bone Joint Surg Am 83(A(9)):1435–1436
van Leeuwen DH, Guitton TG, Lambers K, Ring D (2012) Quantitative measurement of radial head fracture location. J Shoulder Elbow Surg 21(8):1013–1017
Chen FY, Yang CP, Chen PY (2013) Comment on the correct use of predictive values for evaluating diagnostic tests. Radiology 266(1):364–365 (discussion 365-6)
McGee S (2002) Simplifying likelihood ratios. J Gen Intern Med 17(8):646–649
Cyr L, Francis K (1992) Measures of clinical agreement for nominal and categorical data: the kappa coefficient. Comput Biol Med 22(4):239–246
Smits AJ, Giannakopoulos GF, Zuidema WP (2014) Long-term results and treatment modalities of conservatively treated Broberg–Morrey type 1 radial head fractures. Injury 45(10):1564–1568
Hausmann JT, Vekszler G, Breitenseher M, Braunsteiner T, Vecsei V, Gabler C (2009) Mason type-I radial head fractures and interosseous membrane lesions—a prospective study. J Trauma 66(2):457–461
Al-Aubaidi Z, Torfing T (2012) The role of fat pad sign in diagnosing occult elbow fractures in the pediatric patient: a prospective magnetic resonance imaging study. J Pediatr Orthop B 21(6):514–519
Kaas L, van Riet RP, Turkenburg JL, Vroemen JP, van Dijk CN, Eygendaal D (2011) Magnetic resonance imaging in radial head fractures: most associated injuries are not clinically relevant. J Shoulder Elbow Surg 20(8):1282–1288
Hackl M, Lappen S, Burkhart KJ, Neiss WF, Muller LP, Wegmann K (2015) The course of the median and radial nerve across the elbow: an anatomic study. Arch Orthop Trauma Surg 135(7):979–983
Kniesel B, Huth J, Bauer G, Mauch F (2014) Systematic diagnosis and therapy of lateral elbow pain with emphasis on elbow instability. Arch Orthop Trauma Surg 134(12):1641–1647
Kodde IF, Kaas L, Flipsen M, van den Bekerom MP, Eygendaal D (2015) Current concepts in the management of radial head fractures. World J Orthop 6(11):954–960
Zwingmann J, Schmal H, Bayer J, Strohm PC, Südkamp NP (2015) Radiusköpfchen- und Radiushalsfrakturen. Obere Extremität 10:111–118
Irshad F, Shaw NJ, Gregory RJ (1997) Reliability of fat-pad sign in radial head/neck fractures of the elbow. Injury 28(7):433–435
Duckworth AD, Clement ND, Jenkins PJ, Aitken SA, Court-Brown CM, McQueen MM (2012) The epidemiology of radial head and neck fractures. J Hand Surg Am 37(1):112–119
Kaas L, van Riet RP, Vroemen JP, Eygendaal D (2010) The epidemiology of radial head fractures. J Shoulder Elbow Surg 19(4):520–523
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Leschinger, T., Müller, L.P., Hackl, M. et al. The cortical irregularity in the transition zone of the radial head and neck: a reliable radiographic sign of an occult radial head fracture. Arch Orthop Trauma Surg 136, 1115–1120 (2016). https://doi.org/10.1007/s00402-016-2496-7
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DOI: https://doi.org/10.1007/s00402-016-2496-7