International Orthopaedics (SICOT) DOI 10.1007/s00264-017-3451-0
ORIGINAL PAPER
Paediatric lateral humeral condylar fracture outcomes at twelve years follow-up as compared with age and sex matched paired controls Juha-Jaakko Sinikumpu 1 & Tytti Pokka 1 & Sarita Victorzon 2 & Eija-Leena Lindholm 3 & Willy Serlo 1
Received: 3 August 2016 / Accepted: 13 March 2017 # SICOT aisbl 2017
Abstract Introduction Lateral humeral condylar fractures are the second most common elbow fractures in children. We present the long-term clinical and radiographic results. Material and methods All children (5° in 13 cases (40.6%) and in four controls (12.5%, P = 0.013). One in four (N = 8, 25%) of the cases showed cubitus varus >5° and 15.7% (N = 5) had cubitus valgus >5°, compared to one cubitus valgus (3.1%) in controls (P = 0.002). Conclusion The majority of the adolescent and young adult patients (59.4%) with a previous paediatric lateral humeral condylar fracture had recovered well and showed good or excellent overall outcomes according to Flynn’s criteria for elbow assessment after a mean of 12.4 years post-injury. Long-term sequelae was unchanged regardless of treatment.
* Juha-Jaakko Sinikumpu
[email protected]
1
Department of Children and Adolescents, Pediatric Surgery and Orthopedics, Oulu University Hospital, Oulu University, Medical Research Center Oulu, PEDEGO Research Group, P.o. BOX 23, FIN-90029 OYS Oulu, Finland
2
Department of Radiology, Vaasa Central Hospital, Vaasa, Finland
3
Department of Radiology, Oulu University Hospital, Oulu, Finland
Keywords Long-term outcome . Children . Humeral fracture . Lateral condyle
Introduction Lateral humeral condylar fractures are the second most common paediatric elbow fracture after supracondylar humeral fractures [1, 2]. It comprises about 10–20% of all childhood elbow fractures having the annual incidence of 1.6/10,000 [3–5]. Injuries to the elbow are becoming increasingly common [6], partly because of the increasing number of young athletes participating in highly competitive athletics [7]. The mechanism of injury includes either avulsion forces from the lateral ligaments with the elbow extended, or impaction of the radius on the capitellum after a fall on an outstretched arm [8]. Diagnosis is made based on radiographs and it may be difficult in children [9]. Non-displaced and stable fractures may be treated by cast immobilization with close follow-up, but fractures displaced >2 to 3 mm may indicate surgical fixation [10, 11]. Many complications are known to be associated with childhood lateral condylar humeral fractures, with poor outcomes often related to delayed or inadequate initial treatment [9, 12]. Lateral humeral condylar fractures are the most common injuries that involve the growth line around the elbow region [13]. There are also intra-articular fractures, which may affect bone healing and the joint surface [14]. Lateral humeral condylar fractures more commonly result in a decreased range of movement than any other elbow fractures [15]. Up to 20% of patients with lateral condylar fracture show a cubitus varus deformity and >10% show a cubitus valgus deformity [16–18]. Cubitus varus is a potential finding even in nondisplaced fractures and accurate fracture reduction will not always prevent a change in carrying angle [1, 19, 20]. Nonunion is more frequently associated with lateral humeral
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condylar fractures than any other elbow fractures [15, 21, 22] and it usually follows non-operative treatment [23]. Lateral overgrowth of the elbow is a frequent abnormal finding (40– 73%) after lateral humeral condylar fracture [19, 24] but it may have no or only slight effect on function [16]. On the contrary to widely known and relatively usual shortterm risks of lateral humeral condylar fractures, there is just sparse understanding about the long-term outcomes of these fractures in children [22, 25]. Nevertheless, outcomes of childhood lateral humeral condylar fractures are thought to be less satisfactory than outcomes of any other paediatric elbow fracture [1, 8]. In general, the outcomes of children’s injuries need to be evaluated not only by short-term but also by long-term follow-up [26]. The poor results may not be obvious until months or years after the primary injury [8, 20, 27]. This study aimed to evaluate the long-term clinical and radiographic outcomes of childhood lateral condyle humeral fractures after long follow-up.
Material and methods Study design and study setting It is a gender and age matched case–control study, that was performed with on average 12.4 years of follow-up (range 10.6 to 16.0 years) to include children 8 years, P = 0.646) or prepubertal age (5° was taken to be a clinically significant change, while it was classified into four groups (I 15°). Finally, the carrying angle change of every single patient was compared with the corresponding change (difference) in the matched control. The loss of range of rotational motion (RROM) of the forearm was another secondary clinical outcome. In the examination, the subjects were sitting, adducting their arms against the chest and elbows in 90°of flexion. The forearms were in a neutral position while the thumbs were upward. The forearm was first rotated inwards (pronation) and the rotation arch from the neutral position to the maximum pronation was measured by a transparent goniometer. Supination was correspondingly measured by rotating the palm outwards (supination) and measuring the arch from the neutral position to the maximum supination (Table 2). Both injured and uninjured sides were investigated by the same manner, and the difference between the injured and uninjured sides in every patient was calculated and classified in four groups, where a decrease of >5° was taken to be a clinically significant change (I 15°). Supination and pronation movements of every matched control were determined and the potential difference in the RROM between the left and right sides were classified in the same manner. As a consequence, the loss of RROM of every case was finally compared with the corresponding difference (between the sides) of the matched control case. Grip strength, as another secondary outcome variable, was measured from a randomly selected subgroup of the patients (50%, N = 15) and their matched controls with similar handedness, by using a hydraulic Jamar grip dynamometer
(Sammons Preston, Rolyan, Bolingbrook, IL, USA). The best of three attempts was recorded (Table 2). The grip strength of the injured side was compared with the corresponding side of the matched control and no calculations between the injured and uninjured sides of the individuals (patients/controls) were performed because of the known difference between the dominant and non-dominant hands [32]. Physician-based and elbow specific Mayo Elbow Performance Score (MEPS) was used to assess pain, motion, stability and function [33]. A MEPS score of >75 was considered satisfactory while it was recognized that a minimum clinically important difference (MCID) is 15 points [34]. Further, regarding current symptoms, the patients were asked about pain and tolerance of physical activity and work, elements referring to the Quick Disabilities of the Arm, Shoulder and Hand questionnaire (quick-DASH) [35]. Radiographic outcome variables As a separate secondary outcome of the study, the long-term radiographic recovery of lateral humeral condylar fractures of all participants was evaluated by plain radiographs in two projections (anterior-posterior, AP, and lateral). The radiographs were analysed by experienced radiologists (SV, ELL) familiar with paediatric skeleton and trauma. Deformity and degenerative signs were systematically evaluated. Joint space was measured taking 2 mm) displacement) of unsatisfactory Flynn’s criteria. Statistical analyses were carried out using IBM SPSS
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Statistics software version 22.0. All P-values were two-tailed and the threshold of statistical significance was set at P < 0.05.
Grip strength
Results
Grip strength of the injured hand was lower in the patients (38.8 Nm), as compared with the respective side of the paired controls (43.1 Nm), (N = 15, P = 0.046).
Overall long-term recovery
Mayo elbow performance score (MEPS)
The overall outcomes of the elbow, according to the Flynn’s criteria for elbow assessment was decreased in the patients (40.6% fair or poor), compared with the controls (6.3%, P = 0.003). However, most patients (59.4%; N = 19) still reached satisfactory outcome; 12 (37.5%) reached excellent, seven (21.9%) good, eight (25.0%) fair and five (15.6%) poor long-term outcomes according to Flynn’s criteria. No difference in Flynn’s criteria was found between the genders (P = 0.892) or 5° of decrease in flexion-extension range, while the corresponding proportion was 12.5% among the controls (P = 0.013) (Table 3).
Particular subjective symptoms The most frequent long-term symptom was pain (25%, N = 8). Two patients suffered from permanent pain while the other six had occasional pain. Five out of eight patients with pain were operatively treated and three were treated non-operatively. Six patients had decreased tolerance of exercise. No patient had such a severe pain that medical treatment was needed. One patient reported that the injured extremity felt cold (3.1%). Three (9.4%) had symptoms referring to instability (mistrust, clicking). Three (9.4%) of the fractures were tender. Eight (25%) showed crepitus with motion. Radiographic findings Six (18.8%) presented lateral overgrowth. Six (18.8%) had loose bone fragments; five of them were operatively treated. Five (15.6%) had decreased joint space 5° and 15.7% (N = 5) had cubitus valgus >5° compared to the contralateral, uninjured side at follow-up. In contrast, 93.9% showed no deformity regarding the carrying angle in the control group (P = 0.002). The risk of carrying angle change >5° was 8.6-fold in Milch type 1 compared with type 2 (OR 8.6; 95% CI 1.1 to 69.1; P = 0.042). Range of movement of the forearm The cases more frequently showed >5° decrease in rotation movement of the forearm (18.7%), compared with their gender and age matched controls (6.2%) (P = 0.036) (Table 3).
The majority of the adolescent and young adult patients (59.4%) with a previous paediatric lateral humeral condylar fracture had recovered well and showed good or excellent overall outcomes according to Flynn’s criteria for elbow assessment after a mean of 12.4 years post-injury. In turn, lateral condylar humerus fractures resulted in long-term complications and unsatisfactory outcomes in 40.6% of the patients. This major finding of the study strengthens the previous understanding that lateral humeral condylar fractures result in less satisfactory outcomes than other elbow fractures [8], though only limited evidence of their long-term overall results has so far been available [37, 38]. Altogether 15.6% had >15° loss of flexion-extension movement at long-term follow-up. A slight decrease in
International Orthopaedics (SICOT) Table 3 The overall outcomes of the lateral humeral condylar fractures at mean 12 years’ follow-up, according to the Flynn’s criteria for elbow assessment and the secondary study outcomes (range of flexionextension movement, carrying angle, rotation range of movement, Mayo Elbow Performance Score). The outcomes are compared with the corresponding outcomes of the gender and age (+/− 6 months) matched cases
Cases (N = 32)
Controls (N = 32)
Cases
%
N
%
Excellent Good
12 7
37.5 21.9
27 3
84.4 9.4
Fair
8
25.0
1
3.1
Poor Loss of elbow motion (°) (flexion-extension)
5
15.6
1
3.1
15 Change of carrying angle
3
9.4
1
3.1
Flynn’s criteria
No change (10°
3
9.4
0
0
5–10 >10°
2 3
6.3 9.4
1 0
3.1 0
Loss of rotation motion range (°) (pronation-supination) 0–5 5–10 10–15
0.036** 26 0 1
81.3 0 3.1
30 0 2
93.8 0 6.3
>15 Mayo Elbow Performance Score Excellent
5
15.6
0
0
28
87.5
32
100
Good Fair Poor Overall recovery **** Satisfactory
4 0 0
12.5 0 0
0 0 0
0 0 0
19
59.4
30
93.8
Unsatisfactory
13
40.6
2
6.3
ROM was very common; 40.6% of the cases had >5° of decrease in flexion-extension range, compared with 12.5% among the controls. Previously, there is just sparse and controversial evidence about the decreased ROM after lateral humeral condylar fractures, while Koh et al. found no patients with limited ROM in their retrospective patient series (N = 175) [22]. However, the follow-up was only 1.6 years. Bernthal et al. performed a prospective study of 141 patients with lateral humeral condylar fracture and found good recovery of ROM after temporary elbow stiffness [14]. However, a mean follow-up was seven months and no conclusion about the long-term recovery was available. Despite the statistically significant differences in elbow ROM between the cases and the controls in the present study, we still conclude that decreased elbow movements in the patients did not interfere much with their daily activities: all patients achieved
NA***
0.003**
Bexcellent^ in the MEPS regarding elbow motions. Again, the total raw points of MEPS were 97.7 in the patients vs. 100 in controls; the difference between the groups is less than MCID (15 points) and thus not important. We found high prevalence of carrying angle change, while 25% (n = 8) showed cubitus varus and 15.7% (n = 5) had cubitus valgus at a minimum follow-up of ten years. These numbers at the time of long-term follow-up are similar to those shortly after treatment, while the risk of post-traumatic cubitus varus and valgus have been reported to be 20 and 10%, respectively [16–18, 22, 39]. The finding supports the idea that coronal plane carrying angle change will not remodel in ten years, probably partly because the distal humerus counts only 20% of humeral growth [8, 20]. Carrying angle change is mostly a cosmetic problem but it can still result in an altered arc of motion and mechanical symptoms when the elbow is
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Fig. 1 a Antero-posterior radiograph of a male, 24 years, with lateral bone overgrowth and lateral loose bone parts (white arrow) and diminished joint space determined as the shorted perpendicular distance. The patient had Milch type-2 lateral humeral fracture at the age of 11. b Antero-posterior radiograph of a male, 21 years, shows lateral overgworth (white arrow) and decreased perpendicular joint space (black arrow), resulting from a Milch type-1 lateral condylar humerus fracture at the age of seven
axially loaded [40]. A close follow-up has been suggested to monitor for secondary deformities [8]. We also found lateral overgrowth of the humerus in one in five patients (18.8%). It has traditionally been thought as one of the most common residual deformities with the prevalence of about 22% [17, 22, 24]. Isolated studies have reported higher (77%) rates of lateral Bspurring^ [22, 24]. Bony overgrowth over the lateral aspect of the distal humerus is associated with delayed or unsuccessful treatment of lateral condylar humeral fractures [21, 24] but local hyperemia at the fracture site can also lead to stimulation of growth during consolidation [21]. The present study shows that the lateral overgrowth will not remodel over time. Nevertheless, lateral overgrowth often does not interfere with the function of the elbow in daily activities [16, 19]. Diagnosing lateral condylar fractures is challenging because the distal humerus is largely cartilaginous in young children [15]. Further, the fracture line usually lies posterolaterally and may not be captured in the conventional radiographs [1]. Such cartilaginous anatomy affects the prognosis of the lateral humeral condylar fractures: growth disturbance can occur in the form of a partial lateral growth plate closure or partial closure of the centre of the physis [27]. The central insult between the lateral condylar physis and the trochlea can result in a deep groove, forming the typical Bfishtail deformity^ [17]. In this study population no fishtail deformity was found. There are some limitations that need to be recognized. There were ten patients that did not participate. Similar to participants, most of them were males. The mean age of the non-participants was close to that of the participants (7.7 vs. 7.2 years) However, the fracture displacement was in mean 1.8 mm in the non-participants and 6.7 mm in the participants; 40% of the non-participants were operated upon, while 56%
of the participants were operatively treated. It is possible that the participants may have been more concerned about their previous injury and long-term recovery and therefore participated, compared to the non-participants; this may have resulted in the long-term outcomes in this study being worse as compared with the potential situation with full participation. As another limitation, the number of included cases was too small for subgroup analysis regarding different treatment methods. This is an essential question and it would warrant prospective trials to get level-I evidence for or against surgical treatment, especially in the minimally displaced fractures in the future. The natural history of the lateral condylar humeral fractures in the growing skeleton need to be interpreted in view of the growth line injury: type-1 fractures are of SalterHarris type IV, which are more prone to growth disturbance compared to Salter-Harris type II fractures (Milch type-2). Accordingly, there seemed to be higher risk of carrying angle change in connection with more stable Milch type-1 fractures than Milch type-2 fractures in the present study but the subgroups were small. The authentic change of radiographic carrying angle (postoperative vs. long-term) of the patients could not be determined, because not all plain films at the time of cast removal were taken with the elbow in full extension. However, the clinical evaluation of carrying angle (by a goniometer) using the contralateral side as a control is an accepted and widely used method, fundamental in Flynn’s criteria. The risks of both delayed bone healing and non-union have previously been 16% [41] and 15%, respectively [15, 42, 43], but in this long-term study these were not evaluated: by the time of longterm follow-up, bone healing was not an issue any more. We did not assess the quality of reduction, however the findings were still based on a normal children population treated pragmatically in a Western country. We used Flynn’s criteria as the main outcome variable. It is the most widely used scoring system for elbow assessment but it places particular emphasis on the change in carrying angle [44]. In turn, MEPS is excessively affected by pain and it shows high MCID that decreases its value sensitivity [31]. As another limitation, there were a number of outcome variables that were defined prior to study initiation. Repeated tests were therefore performed in order to analyse the hypotheses of primary and secondary outcome variables. It is possible that there was type I error (false positive outcomes), because the statistical significance was not adjusted with the number of tests using, e.g. the Bonferroni method. However, given that several independent tests were performed, the study methods were still clear and the preestablished hypotheses were obvious and reasonable; the reader may reach a reasonable conclusion about the study results. In the future, further studies concerning the sequelae of lateral humeral condylar fractures over a long time period are required to replicate or discard our findings of the high rate of long-term morbidity.
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As a strength, this is the first study to analyse the long-term (mean 12 years) outcomes of childhood lateral humeral condylar fractures by means of sense case–control study setting. The study was performed in a geographical area of two paediatric trauma units. There are no other paediatric trauma centres in the area. Patients treated elsewhere reached the study on the basis of their follow-up visits to study centres. The participation was high enough (76.2%) keeping in mind the long follow-up, and normal age and sex adjusted control cases were evaluated by the same manner as patients. The cases were reasonably similar to the case patients with respect to important determinants of outcome, age and sex, and they represent the population at risk of experiencing the outcome of interest [45]. Statistical comparisons were performed using the matched case–control pairs rather than comparing the groups (cases vs. controls).
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Conclusion 10.
The majority of the pediatric patients with lateral humeral condylar fracture recovered well reaching good or excellent long-term outcomes at 12 years. However, long-term outcome was unsatisfactory in 41% of the patients, while carrying angle change, loss of movements and lateral humeral overgrowth were the most common findings. Compliance with ethical standards Conflict of interests The authors declare that they have no conflict of interest.
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Funding This study was supported by Alma and K.A. Snellman Foundation, Vaasa Foundation of Physicians, The Finnish Medical Foundation, The Emil Aaltonen Foundation, Finska Läkaresällskapet Foundation, the Medical Society of Finland and Foundation for Pediatric Research.
15.
Ethical approval The Ethics Committee of Oulu University Hospital approved the study prior to its initiation (§2008-05-26). Informed consent was obtained from all participants and/or their parents/guardians before inclusion. The study was carried out in compliance with the Helsinki Declaration of 1983.
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Informed consent Informet consent was obtained from all individual participants included in the study.
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