Distal humeral coronal plane fractures: management, complications and outcome

J Shoulder Elbow Surg (2013) 22, 560-566

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Distal humeral coronal plane fractures: management, complications and outcome Mehmet Oguz Durakbasa, MD*, Gurkan Gumussuyu, MD, Mutlu Gungor, MD, Mehmet Nurullah Ermis, MD 2nd Department of Orthopaedics and Traumatology, Haydarpasa Numune Education and Research Hospital, Istanbul, Turkey Background: Coronal plane fractures of the distal humerus have special characteristics in classification, imaging, surgical approaches, materials used, treatment modalities, and complications. The purpose of this study is to comment on these topics. Materials and methods: A retrospective analysis was done for patients with distal humeral coronal plane fractures. They were classified according to Dubberley and functionally evaluated by Mayo Elbow Performance Index (MEPI). The long-term complications were evaluated. Results: There were 15 patients, with type 1 fractures in 2, type 2 in 6, and type 3 in 7. All patients were treated by open reduction and internal fixation either by lateral or posterior approach. The average MEPI score was 83.3 (range, 60-100) points with 7 excellent, 2 good, and 6 fair results. The MEPI scores of type 3 fractures were significantly lower than those of types 1 and 2 fractures (P ¼ .037 and P ¼ .002, respectively). The complications were avascular necrosis in 4 (27%) patients, degenerative arthritis in 6 (40%), joint step-off in 6 (40%), heterotopic ossification in 7 (47%), nonunion in 1 (7%), and implant failure in 1 (7%). The presence of avascular necrosis and joint step-off were significantly associated with degenerative arthritis (P ¼ .004 and P ¼ .005, respectively). Heterotopic ossification was significantly associated with presence of lateral epicondyle fracture (P ¼ .004). Conclusion: Type 1A and 2A coronal plane fractures typically had an excellent outcome. However, type 3 and subtype B fractures are prone to developing complications which are primarily avascular necrosis, degenerative arthritis and heterotopic ossification. Level of evidence: Level IV, Case Series, Treatment Study. Ó 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Coronal plane fracture; headless screws; surgical approach; complications

Coronal plane fractures of the distal humerus involve basically the capitellum and the trochlea, or both. These are entirely cartilage structures and have special characteristics

IRB approval was not required for this study as it was a retrospective review of patient records. *Reprint requests: Mehmet Oguz Durakbasa, MD, SOYAK Gokyuzu Konutlari, C Blok, D: 45, Barbaros Mah., Karayollari Site Sok., no: 5, 34662 Uskudar, Istanbul, Turkey. E-mail address: [email protected] (M.O. Durakbasa).

in classification, imaging, surgical approaches, materials used, treatment modalities, and complications. Several classifications are proposed for coronal plane fractures with some modifications.4,6,17,25 The most recently proposed Dubberley classification takes posterior condylar comminution into account which can be regarded as a prognostic factor.6 Although routine plain radiography is usually insufficient to demonstrate the extent of the injury, a standard lateral view of the elbow can depict the ‘‘double arc’’ sign,

1058-2746/$ - see front matter Ó 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2012.07.011

Distal humeral coronal plane fractures which is a pathognomonic finding, and a radial headcapitellum view can also demonstrate a missed coronal plane fracture.17,33 On the other hand, recent studies emphasize the importance of computerized tomography (CT) and 3-dimensional (3D) CT.8,28,29 These can give information about the fracture fragments, posterior comminution which will enhance the preoperative assessment of the fracture. Coronal plane fractures can be treated by anterolateral, lateral (Kaplan or Kocher), and posterior surgical approaches.13,27 The most commonly preferred approaches are the lateral approach for isolated capitellum fractures and capitellum fractures that extend to the trochlear ridge, and the posterior approach for the fractures that involve both the capitellum and trochlea.16,31 In terms of surgery, the type of the material, the direction of the screws and the number of the screws to be placed remain controversial. The partially threaded cancellous lag screw, headless screw, antiglade anterior plate, Kirschner wire, absorbable pin, and suture are all used to fix these fractures.7,15,28,30 Currently, open reduction and internal fixation (ORIF) is regarded as the best treatment option for coronal plane fractures.6,12,18,25,26 In selected cases, fragment excision,8,24 arthroscopic reduction and percutaneous fixation,14 ORIF combined with hinged elbow fixator,9 or total elbow arthroplasty16,24 can also be considered as satisfactory alternatives. Avascular necrosis (AVN), degenerative arthritis (DA), heterotopic ossification (HO), and nonunion (NU) are reported complications after surgery.3,6,12,18,25,27 The purpose of this study is to retrospectively evaluate the clinical outcomes and complications of the distal humeral coronal fractures in a relatively large group of patients. This study also emphasizes the diagnostic tools that help to classify these fractures correctly, the proper surgical approaches, and the appropriate treatment modality for each fracture type.

Materials and methods A retrospective review of patient files and operation logs between the years 2003-2009 was done. In this period, we treated 51 patients having distal humeral fracture and 19 of them had partial articular fracture. Of these 19 patients, 17 patients had distal humeral coronal plane fractures. Among these, 2 were excluded from the study. One of them had Kocher-Lorenz type fracture and was treated by fragment excision; the other died of chronic renal failure and had insufficient follow-up. Thus the patient population was made up of 15 patients. The fractures were classified according to Dubberley classification system (Fig. 1). Preoperative examination included anteroposterior (AP) and lateral (LAT) x-ray views (Figs. 2, A, and 3, A) and CT scan of the elbow. Postoperative radiographs were taken in the following order: 15 days, 1 month, 2 months, 3 months, 6 months, 1 year, and every year thereafter. The functional evaluation was done by Mayo Elbow Performance Index20 (MEPI) at the last follow-up. At the follow-up visits, the presence

561 of AVN, DA, joint step-off (JS), HO, NU, and implant failure (IF) were evaluated. DA was graded according to Broberg and Morrey system1 and HO was classified by using the Brooker system applied to the elbow2 (Fig. 1). Fracture union was defined as the absence of a visible fracture line on the radiographs and the lack of tenderness along the lateral column.25

Statistical analyses Statistical analyses were made by using the NCSS (Number Cruncher Statistical System, 2007 Statistical Software, UT, USA) programme. The descriptive methods to evaluate the data were the median and the interquartil range. The analytic methods were Kruskal Wallis test for the comparison of groups, Mann-Whitney U test for the comparison of 2 groups, Dunn’s test for the comparison of subgroups, and Fisher exact test for the comparison of the qualitative data. The statistical significance level was set to P < .05.

Results All patients with distal humeral coronal fractures were treated by ORIF. The surgical procedures were carried out by the same surgeon. There were 5 males and 10 females (Table). The mean age was 36 years with a range of 11-76 and the mean follow-up period was 50 months with a range of 24-91. The trauma mechanism was a fall on an outstretched hand in 9 patients, traffic accident as a pedestrian in 3, and a direct blow to elbow in 3. The nondominant, left side was injured in 12 of the cases. Double-arc sign was detected in all type 2 and 3 fractures except for 1 patient with a type 3 fracture. There were two Dubberley type 1 fractures, 6 type 2 (five 2A, one 2B), and 7 type 3 (two 3A, five 3B). The mean time from admission to operation was 8 days with a range of 1-19. The lateral approach which was described by Kaplan as the interval between extensor digitorum communis (EDC) and extensor carpi radialis brevis (ECRB) was used for all of type 1 and 2 fractures and for 3 of type 3 fractures. In these patients, the origin of the wrist extensors and lateral collateral ligament complex (LCLC) were elevated from the lateral epicondyle and the lateral joint space was opened with a medial translation of the elbow joint by exerting a varussupination force on it (Fig. 2, B). After fixation of the fracture, the elevated structures were secured to their anatomical place by using suture anchors or number 2 polyglactin 910 through a tunnel created in the lateral epicondyle. The remaining 4 type 3 fractures were managed by posterior approach. The technique was the posterior approach described by Bryan-Morrey in 1 patient (Fig. 3, B) and transolecranon approach in 3. Among these latter 3 patients, a chevron osteotomy was done in 2 patients, and it was fixed by an intramedullary spongios screw. There was already an olecranon fracture present in the remaining

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Figure 1

Classification and evaluation methods used in the study.

patient that was fixed by Kirschner (K-) wires with a tension band technique. An osteosynthesis with multiple K-wires was done in 1 patient with type 3B fracture. The remaining 14 fractures were fixed with more than 1 screw (Herbert or Acutrak screws) with K-wires added to the osteosynthesis when needed. Active range of motion (ROM) exercises were begun immediately after the operation in type 1 and 2 fractures. In type 3 fractures, an above-the-elbow splint was used for a maximum period of 10 days postoperatively until edema subsided and active ROM exercises were initiated thereafter.

Indomethacin, 25 mg, 3 times a day for three weeks, was given orally for HO prophylaxis. The fractures were uneventfully united within 3 months in all but 1. The average MEPI score was 83.3 (range, 60100) points with 7 excellent, 2 good, and 6 fair results. There were no accompanying neurovascular injuries in any patient. There were 8 concomitant lateral epicondyle fractures. No instability was detected in any 1 of the patients at the final follow-up. The complications were AVN in 4 (27%) patients, DA in 6 (40%), JS in 6 (40%), HO in 7 (47%), NU in 1 (7%), and IF in 1 (7%). All patients who developed AVN had had type 3 fractures. DA developed in

Distal humeral coronal plane fractures

Figure 2 A, Preoperative radiographs of case 1. B, Type 2A fracture was exposed by lateral approach with the LCLC stripped off from the lateral epicondyle. The elbow was opened laterally with a medial translation of the elbow joint and the lateral portion of the trochlea could be instrumented. C, The radiological outcome of the case presented in A and B. There were no complications. The clinical result was excellent with a MEPI score of 100 points (follow-up: 46 months).

5 of type 3 fractures and 1 of type 2. HO was detected only in type 3 fractures. At the last follow-up, the median MEPI score was 100 points (IQR 100-100) for type 1 fractures, 100 points (IQR 95-100) for type 2, and 65 points (IQR 60-70) for type 3 (Fig. 2, C, and Fig. 3, C). There was a significant difference among MEPI scores of 3 types of fractures (P ¼ .003). The MEPI scores of type 3 fractures were significantly lower than those of the type 1 and 2 fractures (P ¼ .037 and P ¼ .002, respectively). On the other hand, there was no significant difference between the MEPI scores of type 1 and 2 fractures (P ¼ .564) and between type 3A and 3B fractures (P ¼ .095).

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Figure 3 A, Preoperative radiographs of case 2. B, Type 3B fracture was exposed by posterior (Bryan-Morrey triceps splitting) approach. 1: Ulnar nerve. 2: Olecranon. 3: Distal humeral shaft 4. Triceps splitted from medial to lateral. The capitellum and the trochlea were fixed together by cannulated screws (5) and to the humeral shaft by a K-wire through the medial epicondyle (6) and a conic screw through the capitellum (7). C, The radiological outcome of the case presented in A and B showing BrobergMorrey grade 2 degenerative arthritis and Brooker type 3 heterotopic ossification. The clinical result was fair with a MEPI score of 70 points (follow-up: 34 months).

Among the 6 patients who developed DA, 5 were grade 2 and 1 was grade 3, according to Broberg-Morrey classification. DA developed in all 4 (100%) of those who had AVN and in 2 (18.2%) of those 11 patients who did not have AVN. There was a statistically significant difference between these 2 groups in developing DA (P ¼ .004). DA developed in 5 (83.33%) of those 6 patients who developed JS and in 1 (11.11%) of those 9 who did not, and the difference was statistically significant (P ¼ .005). The MEPI scores of patients who developed DA were significantly lower than those who did not develop DA (P ¼ .002). There were 7 patients all with type 3 fractures who developed HO. That was grade 1 in 1 patient, grade 2 in 2, and grade 3 in 4, according to Brooker classification applied

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Table I

Demographics, results and complications of the patients

No. Age Gender Side

Fracture Time to Follow-up MEPI AVN DA HO Lateral JS type surgery (months) score (Broberg (Brooker) epicondyle (days) Morrey) fracture

IF

Incision

Olecranon osteotomy

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

3A 1A 3B 1A 2A 3B 2A 2A 3B 2A 3A 2A 2B 3B 3B

No No No No No No No No No No No No No No Yes

Lateral Lateral Posterior Lateral Lateral Posterior Lateral Lateral Lateral Lateral Lateral Lateral Lateral Posterior Posterior

No No Yes No No Yes No No No No No No No No Olecranon fracture

20 28 30 76 29 38 12 13 58 11 66 11 31 61 53

Male Female Male Female Female Male Male Male Female Female Female Female Male Female Female

Left Left Left Left Right Right Left Left Left Left Right Left Left Left Left

9 1 6 18 10 12 6 6 9 11 11 8 9 4 7

91 79 75 63 56 52 49 46 41 40 40 27 35 34 24

70 100 60 100 100 65 100 100 65 100 80 100 80 70 60

No No Yes No No Yes No No Yes No No No No No Yes

to the elbow. A lateral epicondyle fracture was associated in all 7 (100%) of those patients who developed HO and in 1 of 8 (12.5%) who did not. There was a statistically significant difference between these 2 groups (P ¼ .004). There was no statistically significant difference between the time from injury to surgical intervention either between patients who developed AVN and who did not (P ¼ .753) or between patients who developed DA and who did not (P ¼ .955). The time from injury to surgical intervention did not show a significant correlation with the MEPI scores (r ¼ .076, P ¼ .787). AVN, DA, and MEPI scores were not associated with the time from injury to surgical intervention (P > .05). The patient who had an IF had also AVN of the capitellum and the trochlea. This case developed NU but the patient refused any further intervention.

Discussion Distal humeral coronal plane fractures are rare in all age groups.32 In a recent report, 15% of the distal humeral fractures were partial articular fractures and 79% of these were coronal plane fractures.12 In the present study, the relevant ratios were found to be 37% and 89%, respectively. It is noteworthy that 4 patients out of 19 were adolescents in the present study indicating that distal coronal plane fractures should be looked for in the adolescent elbow trauma. Adolescents nearly always have type 1 or 2 fractures.5 The expected and the actual prognosis are good in adolescents mostly because of the type of the fracture. The four adolescents of the present study had also type 2A fractures and had good prognostic outcomes. On the contrary, fractures in the elderly are more frequently type 3 fractures most likely because of presence of osteoporosis. Type 3 fractures are associated with a poorer prognosis.

No No Grade No No Grade No No Grade No No No Grade Grade Grade

2

2

2

2 2 3

Grade No Grade No No Grade No No Grade No Grade No No Grade Grade

2 3

3

3 2

3 1

Yes No Yes No No Yes No No Yes No Yes No Yes Yes Yes

Yes No Yes No No Yes No No Yes No No No Yes No Yes

Female predominance and nondominant side predominance in distal humeral coronal plane fractures were previously reported.18 These constituted 67% and 80% of the cases respectively in the present series. Female predominance was attributed to cubitus valgus and cubitus recurvatum seen mostly in females.23 Nondominant side predominance can be attributed to either decreased bone density observed in the nondominant extremity compared to the dominant one or a human reflex to fall on the nondominant side in order not to injure the dominant one. There are various classification systems defined for the distal humeral coronal plane fractures.4,6,17,25 Dubberley et al recently proposed a new classification system which takes posterior comminution of the distal humeral condyles into account.6 By its virtue of giving information about the prognosis of the fracture, the Dubberley classification seems more suitable than the others. In the present study, there was no significant difference between the MEPI scores of type 3A and 3B fractures. On the other hand, the present study showed that the posterior comminution is likely to have a negative effect on the final outcome because type 2B and 3B fractures had lower MEPI scores compared to type 2A and 3A fractures, respectively. The ‘‘double arc sign’’ detected on the lateral radiograph of the elbow represents a rotated capitellotrochlear fragment.17 This is a pathognomonic sign which distinguishes the isolated capitellum fractures from the fractures that extends to the trochlea, as it was detected in all of the type 2 and 3 fractures except for 1 patient with a type 3 fracture in the present series. In the patient with a type 3 fracture but without the sign, it was later realized that the lateral radiograph of the elbow was not taken in the standard plane yielding a misinterpretation. Therefore, it is essential to take a standard lateral radiograph with the elbow flexed 90 degrees and the forearm in neutral

Distal humeral coronal plane fractures position in the trauma scene to elucidate this pathognomonic sign. CT and 3-D CT are recommended for determining the exact nature of the fracture morphology and for the operative decision-making.10,25,29 CT scan is actually very useful to evaluate the fracture pattern, the number of the fracture pieces and the presence of posterior comminution and lateral epicondyle fracture enabling the determination of the fracture type, the approach for surgical intervention, the fixation material and the probable complications particularly the AVN, DA, and HO. Lateral17,19,31 and posterior approaches22,34 are commonly used for distal humeral coronal plane fractures. The authors of the present study believe that Kaplan approach is sufficient for all Dubberley type 1 and 2 fractures and for selected cases with type 3A fractures. In type 2 and 3A fractures, we recommend that the origin of the wrist extensors and LCLC is stripped off the lateral epicondyle and the elbow is translated medially. This approach facilitates the manipulation, anatomic reduction and fixation of the fractured fragment as the instruments can be used more easily, the screws can be applied vertically to the fracture line and more than 2 screws can be used if the fracture extends to the trochlea. In our opinion, the absolute indication for a posterior approach is a type 3B fracture only. By that approach, the distal humeral cartilage can be exposed entirely and complex procedures such as reduction of multiple fragments, elevation of impacted fragments and bone grafting can be performed. Treatment options for distal humeral coronal plane fractures are numerous.8,9,14,21 ORIF is the recommended treatment of choice in the current management of these fractures to achieve stable anatomic reduction, restore articular congruity and initiate early motion.27 We think every effort should be made to fix the fracture for all kinds of capitellar and trochlear fractures in the young. For elderly people, fragment excision for Kocher-Lorenz type fracture can be a treatment option. Additionally, total elbow arthroplasty for type 3 fractures can be considered as the bone quality might be poor and stable rigid fixation could not be obtained. It is wise to prepare the total elbow arthroplasty set ready in the operating room. Various fixation methods were proposed for coronal plane fractures. Acutrak screws inserted anteroposteriorly are proposed to be the most stable fixation method according to some biomechanical test results.7 We think headless screws, namely Herbert and Acutrak screws, apply compression on the fracture site which facilitates fracture healing and their use in AP direction gives desirable results. We prefer to use at least two screws for adequate fracture stability that can allow immediate postoperative active motion. When an impacted fragment is detected, the impacted fragment is reduced such that meticulous attention is spent for joint surface reduction and not to free the fragment from its bed.

565 It is previously reported that type 1 fractures have significantly better outcomes than types 2 and 3 fractures and the greater the fragmentation of the articular surface, the worse the outcome.6,12 In the present study, type 1A and 2A fractures had a MEPI score of 100 with no complications at all. Type 3 fractures yielded significantly worse results than both type 1 and 2 fractures. Furthermore, the B subtype had the worst outcomes. The reported complications in distal humeral coronal plane fractures can be evaluated by two aspects, namely, the reoperations and the complications related to the radiological findings. The reoperation rates were reported to be 48% and 43% in 2 previously reported series.6,25 The reasons to reoperate were painful hardware, decreased ROM, NU, loss of fixation and ulnar neuropathy.6,25,35 No ulnar neuropathy was detected in the present series. There were no reoperations done in the current study, but it was offered in one patient. The radiologically detected complications are DA, AVN, HO, JS, loss of fixation and NU.3,11,18,25,26,27 In the current study, the incidence of AVN was found to be 27%, DA 40% and HO 47%. All of the 3B fractures and B subtype fractures resulted in DA. DA was significantly associated with both AVN and JS. HO is significantly associated with lateral epicondyle fracture. Brouwer et al reported that type 3B fractures had a significantly higher rate of NU than the other types.3 Similarly, the only patient who developed a nonunion in this study had a type 3B fracture. It is possible that the posterior comminution and fragmentation in type 3B fractures lead to AVN and loss of fixation and result in NU.

Conclusion The Dubberley classification system is suitable to classify distal humeral coronal plane fractures. The ‘double arc’ sign is pathognomonic in type 2 and 3 fractures if a standard lateral radiography of the elbow is obtained. Type 1, 2, and 3A fractures can be managed by the Kaplan lateral approach and type 3B by the posterior approach. While type 1A and 2A fractures have excellent results, type 3B and subtype B fractures have the worst outcomes with resultant DA. DA development is significantly associated with presence of both AVN and JS. HO development is significantly associated with presence of lateral epicondyle fracture.

Disclosure None of the other authors, their immediate families and any research foundation with which they are affiliated received any financial payments or other benefits from any commercial entity related to the subject of this article.

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