Advertisement

Mid-term follow-up results of calcaneal reconstruction for calcaneal malunion

  • Hong Seop Lee
  • Woo Jong Kim
  • Eun Seok Park
  • Jun Young Kim
  • Young Hwan Kim
  • Young Koo LeeEmail author
Open Access
Research article
  • 128 Downloads
Part of the following topical collections:
  1. Orthopedics and biomechanics

Abstract

Background

We hypothesized that calcaneal reconstruction can relieve chronic pain due to calcaneal malunion. We report the mid-term follow-up results of calcaneal reconstruction for calcaneal malunion.

Methods

We reviewed the records of 10 male patients (10 ft) who underwent calcaneal reconstruction for calcaneal malunion between January 2009 and July 2014 at the mid-term follow-up. Talocalcaneal height and angle, calcaneal pitch, calcaneal width, Böhler angle, Stephens classification, and Zwipp classification were evaluated by three orthopedic doctors at each visit (pre-reconstruction, post-reconstruction, and at the last follow-up).

Results

The mean follow-up period was 67.1 months (range, 48–101 months). The sites of pain before reconstruction were lateral aspect (4 patients), plantar aspect (3 patients), diffuse pain (2 patients), and anterior aspect (1 patient). There was a significant difference in talocalcaneal height, talocalcaneal angle, calcaneal pitch, calcaneal width, and Böhler angle before and after reconstruction (p < 0.05). There was no significant difference between reconstruction and the last follow-up. Radiological measurement agreement was calculated to be moderate to strong (intraclass correlation coefficient: 0.659–0.988). Mean American Orthopedic Foot & Ankle Society Ankle and Hindfoot score improved from 66.50 ± 9.37 pre-reconstruction to 80.30 ± 8.52 at the last follow-up (p < 0.05). The mean visual analog scale score improved from 8.60 ± 1.43 before reconstruction to 3.40 ± 0.84 at the last follow-up (p < 0.05). Most patients were satisfied with the outcome postoperatively.

Conclusions

Our results showed substantial improvement in the clinical and radiological outcomes after calcaneal reconstruction of calcaneal malunion. This outcome was maintained until the mid-term follow-up. Therefore, calcaneal reconstruction may be a good option for the treatment of chronic pain caused by the malunion of a calcaneal fracture without severe subtalar arthritis. Further prospective studies are needed to test this theory.

Level of Evidence: Level IV, Retrospective Case Series.

Keywords

Calcaneus fracture Calcaneus reconstruction Mid-term follow-up Hindfoot 

Abbreviations

AOFAS

American Orthopedic Foot & Ankle Society

VAS

Visual Analogue Scale

Background

Calcaneal fractures are a common fracture in the hindfoot caused by a high energy trauma, such as a fall or motorcycle accident [1]. Ninety percent of calcaneal fractures occur in workers in their 20s to 40s [1]. Calcaneal fractures can be complicated by subtalar arthritis and malunion, leading to persistent postoperative pain and low patient satisfaction [2, 3]. Decreased Bohler’s angle is known to be a poor prognostic factor [4, 5]. Malunion is related to the primary fracture patterns. Pain associated with malunion can be variable in origin, such as peroneal tendon or lateral malleolus impingement due to widening of the calcaneus, anterior tibio-talar impingement due to a loss of height leading to a decrease in the talar inclination angle, and varus or valgus alignment causing pain during ambulation. Traditionally, corrective fusion was the mainstay treatment for malunion, and many studies have reported favorable results [6, 7]. Alternatively, subtalar joint fusion is a salvage procedure, which leads to a decrease in the range of motion and function, and it may lead to periarticular joint arthritis.

We previously reported favorable results during a short-term follow-up after calcaneal reconstructions for correction of the height and width of the malunited calcaneus [8]. In the present study, we hypothesize that calcaneal reconstructions will relieve pain for patients who have no severe subtalar arthritis but have chronic pain due to calcaneal malunion. The purpose of this study was to report the mid-term follow-up of the clinical and radiological results of calcaneal reconstruction of calcaneal malunion.

Methods

Patients

The inclusion criteria were as follows: diagnosis of post-calcaneus fracture malunion; previous operative history for a calcaneal fracture; calcaneal reconstruction surgery for calcaneal malunion; postoperative follow-up of a minimum of 4 years; and symptoms of postoperative pain. The exclusion criteria were patients who had severe subtalar arthritis or those who underwent subtalar arthrodesis or a simple ostectomy.

Between January 2009 to July 2014, 34 patients (37 ft) underwent calcaneal reconstruction for the dysfunction and pain caused by malunion. We reviewed 10 patients (10 ft) postoperatively at the mid-term follow-up. Patient enrollment is described in Fig. 1. This study was approved by the institutional review board of our hospital. We obtained informed consent from all patients.
Fig. 1

This figure shows the number of patients included in this study

We evaluated the patients, including the site of pain and range of ankle motion. Radiological examinations of the foot in the weight-bearing anteroposterior and lateral views as well as a hindfoot alignment view were performed. Talocalcaneal height and angle, calcaneal pitch, calcaneal width, and the Böhler angle were measured three times by three different orthopedic doctors at each of the visits (pre-reconstruction, post-reconstruction, and final follow-up). In addition, three different orthopedic doctors classified patients according to the Stephens classification and Zwipp classification at each of these visits [9, 10]. Lateral wall bumpectomy was performed in patients with lateral impingement or without significant loss in calcaneal height; the remaining patients underwent calcaneal reconstruction involving calcaneal osteotomy followed by repositioning and fixation of the calcaneal tuberosity fragment. Postoperatively, a short leg splint was applied for 2 weeks followed by another 2 weeks with a short leg cast. After full weight-bearing was possible, postoperative shoes were used for 2 months. Subtalar fusion was performed in patients with persistent subtalar pain, no improvement in symptoms, or a limited range of motion. The American Orthopedic Foot & Ankle Society (AOFAS) Ankle and Hindfoot score and visual analog pain scale (VAS) were obtained postoperatively and at the final follow-up. The subjective satisfaction of each patient was assessed with a survey.

Operative technique

Patients were placed in the lateral decubitus position on a beanbag, with the foot to be operated on facing upward. We applied a thigh tourniquet, which was inflated to 300 mmHg. We used the standard extensile lateral approach to the calcaneus. An incision was made on the vertical limb just anterior to the Achilles tendon, allowing the sural nerve to be protected within the full-thickness flap. We took care not to injure the sural nerve at the distal end of the incision. Three 1.6-mm Kirschner wires were inserted into the lateral malleoli, talar neck, and the cuboid to protect the peroneal tendons and the full-thickness flap. We performed a lateral wall bumpectomy if impingement syndrome was present in the subfibular area. A downward oblique osteotomy was started from the calcaneal lateral wall and proceeded to the medial calcaneal wall. Two temporary pin fixations on the calcaneal lateral wall and the tuberosity fragment were slid downward using a compressor (Fig. 2). Finally, we fixed the osteotomy site in the correct position with two 6.5 mm cannulated screws and staples (Fig. 3).
Fig. 2

a. A standard extensile lateral approach is marked on the calcaneus. b. A lateral bumpectomy is carried out. c. A downward oblique osteotomy is done on the calcaneal lateral wall. d. Two temporary pin fixations are fixed on the calcaneal lateral wall and the tuberosity fragment is slid downward using a compressor

Fig. 3

The osteotomy site is fixed with two 6.5 mm cannulated screws

Statistical analysis

The Statistical Package for the Social Sciences version 20.0 (IBM Corp., Armonk, NY, USA) was used for the statistical analysis. The McNemar test, paired t test, and intraclass correlation coefficient were used. The sample size was calculated using the PS program [11]. Considering previous studies, we assumed that the minimum clinically significant difference in the mean AOFAS Ankle and Hindfoot score would be 8, ranging 6–10 standard deviations between the baseline and follow-up [8]. We calculated a sample size of 9 to detect the minimum clinically significant difference with power of 80% and an alpha error of 5%.

Results

The study included 10 male patients with a mean age of 46.3 years (range, 31–6 years). The mean interval between the first operation and the reconstruction surgery was 16.6 months (range, 7–59 months). The mean follow-up period was 67.1 months (range, 48–101 months) after calcaneal reconstruction. The sites of pain before the reconstructive operation were the lateral aspect (4 patients), plantar aspect (3 patients), diffuse pain (2 patients), and anterior aspect (1 patient).

The results of the radiological measurements and classifications by three different orthopedic doctors are summarized in Table 1 (A, B, and C). There was a significant difference in talocalcaneal height, talocalcaneal angle, calcaneal pitch, calcaneal width, and Böhler angle before and after reconstruction (p < 0.05). No significant differences were observed between reconstruction and the final follow-up.
Table 1

Results of radiologic measurements and classifications by three different orthopedic doctors

 

Pre-reconstruction period

Post-reconstruction period

 

Post-reconstruction period

last follow up

 

Number of patients

Number of patients

p-value

Number of patients

Number of patients

p-value

Stephens classification

  

0.072

  

0.564

Type I

1

4

 

4

3

 

Type II

2

5

 

5

6

 

Type III

7

1

 

1

1

 

Zwipp classification

  

0.199

  

0.513

Type 1

0

4

 

4

3

 

Type 2

2

2

 

2

4

 

Type 3

7

4

 

4

3

 

Type 4

1

0

 

0

0

 

Type 5

0

0

 

0

0

 
 

Mean ± SD

Mean ± SD

p-value

Mean ± SD

Mean ± SD

p-value

Talocalcaneal Height(mm)

73.17 ± 4.42

80.83 ± 3.66

< 0.05

80.83 ± 3.66

80.00 ± 0.2

0.352

Talocalcaneal Angle (°)

29.69 ± 4.99

37.55 ± 5.36

< 0.05

37.55 ± 5.36

38.40 ± 5.28

0.724

Calcaneal Pitch(°)

17.24 ± 5.07

23.74 ± 4.26

< 0.05

23.74 ± 4.26

24.40 ± 4.17

0.663

Calcaneal Width(mm)

43.46 ± 4.89

41.60 ± 5.45

< 0.05

41.60 ± 5.45

41.90 ± 5.92

0.603

Bohler Angle(°)

6.9 ± 10.09

17.79 ± 10.43

< 0.05

17.90 ± 10.44

17.40 ± 10.62

0.296

 

Pre-reconstruction period

Post-reconstruction period

 

Post-reconstruction period

last follow up

 

Number of patients

Number of patients

p-value

Number of patients

Number of patients

p-value

Stephens classification

  

0.112

  

0.564

Type I

1

4

 

4

3

 

Type II

3

5

 

5

6

 

Type III

6

1

 

1

1

 

Zwipp classification

  

0.199

  

0.513

Type 1

0

4

 

4

3

 

Type 2

2

2

 

2

4

 

Type 3

7

4

 

4

3

 

Type 4

1

0

 

0

0

 

Type 5

0

0

 

0

0

 
 

Mean ± SD

Mean ± SD

p-value

Mean ± SD

Mean ± SD

p-value

Talocalcaneal Height(mm)

71.49 ± 5.95

78.44 ± 2.74

< 0.05

78.44 ± 2.74

78.06 ± 2.59

0.509

Talocalcaneal Angle (°)

29.38 ± 5.43

30.54 ± 5.01

< 0.05

30.54 ± 5.01

30.37 ± 7.06

0.889

Calcaneal Pitch(°)

17.10 ± 6.14

23.60 ± 5.47

< 0.05

23.60 ± 5.47

22.66 ± 5.45

0.069

Calcaneal Width(mm)

42.94 ± 5.93

40.92 ± 5.50

< 0.05

40.92 ± 5.50

41.19 ± 6.03

0.526

Bohler Angle(°)

6.20 ± 10.51

19.11 ± 11.83

< 0.05

19.11 ± 11.83

18.80 ± 11.50

0.484

 

Pre-reconstruction period

Post-reconstruction period

 

Post-reconstruction period

last follow up

 

Number of patients

Number of patients

p-value

Number of patients

Number of patients

p-value

Stephens classification

  

0.072

  

0.999

Type I

1

4

 

4

4

 

Type II

3

5

 

5

5

 

Type III

6

1

 

1

1

 

Zwipp classification

  

0.363

  

0.317

Type 1

1

4

 

4

4

 

Type 2

3

2

 

2

1

 

Type 3

5

4

 

4

5

 

Type 4

1

0

 

0

0

 

Type 5

0

0

 

0

0

 
 

Mean ± SD

Mean ± SD

p-value

Mean ± SD

Mean ± SD

p-value

Talocalcaneal Height(mm)

74.20 ± 6.05

78.20 ± 6.07

< 0.05

78.20 ± 6.07

77.00 ± 4.40

0.479

Talocalcaneal Angle (°)

33.50 ± 7.44

35.90 ± 7.03

< 0.05

35.90 ± 7.03

38.00 ± 4.62

0.305

Calcaneal Pitch(°)

19.10 ± 5.26

24.70 ± 5.74

< 0.05

24.70 ± 5.74

24.30 ± 5.21

0.494

Calcaneal Width(mm)

42.88 ± 5.96

40.27 ± 6.25

< 0.05

40.27 ± 6.25

40.71 ± 6.28

0.303

Bohler Angle(°)

5.80 ± 10.42

18.30 ± 12.26

< 0.05

18.30 ± 12.26

18.81 ± 12.37

0.315

A. Results of first orthopedic doctor

The radiological measurement agreement among the three observers was calculated using the intraclass correlation coefficient, which was found to be moderate to strong (0.659–0.990) (Table 2).
Table 2

Radiologic agreements using Intraclass Correlation Coefficient

 

Value of ICC (95%CI)

  

Pre reconstruction

Post reconstruction

Last follow up

Talocalcaneal Height(mm)

0.953 (0.862–0.987)

0.697 (0.114–0.918)

0.659 (0.001–0.908)

Talocalcaneal Angle(°)

0.858 (0.585–0.962)

0.550(−0.318–0.878)

0.923 (0.774–0.979)

Calcaneal Pitch(°)

0.926 (0.785–0.980)

0.886 (0.67–0.969)

0.859 (0.586–0.962)

Calcaneal Width(mm)

0.969 (0.908–0.992)

0.912 (0.756–0.969)

0.982 (0.946–0.995)

Bohler Angle(°)

0.981 (0.944–0.995)

0.990 (0.969–0.997)

0.988 (0.966–0.997)

ICC Intraclass Correlation Coefficient, CI Confidence Interval

At the final follow-up, 3 patients were very satisfied, 5 patients were satisfied, and 2 patients were not satisfied. In addition, the mean AOFAS Ankle and Hindfoot score improved from 66.50 ± 9.37 pre-reconstruction to 80.30 ± 8.52 at the final follow-up (p < 0.05) (Table 3). The mean VAS score improved from 8.60 ± 1.43 pre-reconstruction to 3.40 ± 0.84 at the final follow-up (p < 0.05). Although the pain did not completely resolve, most of the patients were satisfied postoperatively.
Table 3

AOFAS Ankle and Hindfoot score change between pre-reconstruction and last follow-up

AOFAS score

Pre-reconstruction

Last follow-up

p-value

Pain

23.5 ± 3.57

30.7 ± 4.10

< 0.05

Function

35.1 ± 5.81

40.7 ± 6.78

< 0.05

Alignment

6.4 ± 2.10

8.9 ± 2.50

< 0.05

Overall

66.50 ± 9.37

80.30 ± 8.52

< 0.05

AOFAS American Orthopedic Foot & Ankle Society

In the postoperative period, superficial wound infection occurred in 4 of the 37 ft (10.8%). Infections resolved with oral antibiotics and simple dressings and did not develop into further complications.

Discussion

The most important finding of this study was that there was a statistically significant improvement in the radiographical and clinical outcome of calcaneal reconstruction for calcaneal malunion at the mid-term follow-up. Satisfactory short-term follow-up results were also previously reported in 10 patients with an average follow-up period of 14 months [12]. In our former study on 24 patients with an average follow-up period of 11.2 months, favorable results in the radiographic parameters and patient subjective satisfaction were observed [8]. To the best of our knowledge, this is the first study to report on the mid-term follow-up results for calcaneal reconstruction of calcaneal malunion.

The principle goal of our calcaneal reconstruction was improvement of the talocalcaneal relationship through restoration of calcaneal height. Restoration of calcaneal height relieves the anterior tibiotalar impingement as the horizontal talus is changed to vertical. Decreased Achilles tendon lever-arm due to calcaneal height loss is also improved through restoration of calcaneal height.

The optimal treatment of calcaneal fractures is still controversial among orthopedic surgeons [13]. A recent prospective, randomized, controlled multicenter study reported that in short term follow-up, operative treatment for displaced intra-articular calcaneal fracture was not superior to non-surgical treatment, however, in midterm follow-up, there were several favorable results for surgical repair [14]. An economic evaluation study comparing operative and nonoperative management of intra-articular displaced calcaneal fractures reported that operative management was more economical [15]. Anatomic reduction and firm fixation results in favorable outcomes in terms of subjective patient’s satisfaction, early rehabilitation, painful subtalar arthritis, and subtalar fusion rate [16, 17, 18]. Another prospective, randomized, controlled multicenter study reported that non-operative treatment for displaced intra-articular calcaneal fractures had equivalent functional results to those after operative treatment [19]. However, both operative and non-operative treatment can result in symptomatic malunion with severe functional disability that may impact the patient’s quality of life [5, 20].

To the best our knowledge, there is no report on effective nonoperative treatment for calcaneal malunion. For all patients, nonoperative treatment for calcaneal malunion with customized insole use for at least 6 months failed. The morphological changes of the calcaneal malunion do not improve with nonoperative treatment including orthotics and insoles.

Several studies have associated the pathological cause of the symptoms in calcaneal malunion with the pattern of the calcaneal fracture [15, 16]. They explained that a primary fracture coursing superolateral to inferomedial or anterolateral to posteromedial caused lateral and proximal displacement of the tuberosity fragment, leading to a loss of height, widening of the heel, and lateral impingement.

Recently, Savva et al. reported the results of in situ arthrodesis with lateral wall ostectomy for complication of calcaneal fractures [21]. They recommended in situ subtalar arthrodesis with lateral wall ostectomy for subtalar arthritis following calcaneal malunion, regardless of the degree of calcaneal height loss. Their results suggested that anterior tibiotalar impingement is not a significant problem after subtalar fusion. Clare et al. reported the intermediate- to long-term results of their operative protocol for calcaneal malunion [22]. They proposed an operative protocol based on Stephens classification. Since restoration of calcaneal height loss is difficult, they emphasized the importance of acute surgery for displaced intra-articular calcaneal fracture. Yu et al. reported the clinical and radiologic outcomes of reconstructive osteotomy and bone graft for calcaneal malunions [23]. They restored the displaced posterior facet through calcaneal osteotomy and an iliac bone graft filler.

Similarly, in 1993, Romash first introduced the concept of calcaneal reconstruction based on reversing the deformity associated with the later complications [12]. Reconstructive osteotomy permits the repositioning of the tuberosity, which narrows the heel, resolves impingement, and restores heel height. Clare et al. reported a lateral closing wedge osteotomy to correct a severe varus deformity and medializing calcaneal osteotomy by rotating the tuberosity for the severe valgus deformity [22].

For the evaluation of calcaneal malunion, Böhler’s angle with a the lateral view, the talocalcaneal angle, and the height of the calcaneus are most commonly used [4, 24].] Since malunion leads to a decreased talocalcaneal angle and talar inclination angle, an increasing deformity of the calcaneus occurs, indicating tibiotalar impingement [12, 24]. Similarly, the results from our previous study also suggested a statistically significant increase in the talocalcaneal angle after calcaneal reconstruction [8].

In calcaneal malunion, etiologies can vary depending on the site of pain [1, 3]. The primary cause of lateral pain is subtalar arthrosis. Symptomatic subtalar arthrosis is characterized by the aggravation of pain with palpation of the sinus tarsi. Peroneal tendon pathology, calcaneocuboid arthrosis, hardware irritation, and sural nerve impingement can also be a source of lateral pain. Anterior pain is caused primarily by anterior talar neck impingement on the distal tibia, resulting from the loss of calcaneal height. Plantar pain is caused by plantar exostosis or heel pad injury. Medial pain may be the result of tarsal tunnel syndrome or a flexor hallucis longus tendon problem. Nerve-related problems or complex regional pain syndrome can induce poorly localized pain. In our study, the site of pain was in the lateral aspect (4 patients), plantar aspect (3 patients), diffuse pain (2 patients), and anterior aspect (1 patient). Patients with calcaneal malunion complain of various areas of pain. Restoration of calcaneal height through calcaneal reconstruction could improve anterior and plantar pain. Lateral wall bumpectomy could improve lateral pain.

There are several limitations to this study. Although we calculated a sample size on the basis of our previous study, there is a bias due to small sample size. A larger group of patients and a longer follow-up period are needed. Furthermore, our study did not involve a control group. It may be interesting to compare the clinical and radiologic changes following our reconstruction technique versus the changes seen following subtalar arthrodesis. As our study is limited to a retrospective review, further prospective studies are needed. Our technique is associated with the risk of development of subtalar arthritis in the long term, which could require subtalar arthrodesis in the future. Long-term follow-up is needed to evaluate the occurrence of subtalar arthritis in the future.

Conclusions

Our results showed substantial improvement in the clinical and radiological outcomes after calcaneal reconstruction of calcaneal malunion. This outcome was maintained until the mid-term follow-up. Therefore, calcaneal reconstruction may be a good option for the treatment of chronic pain caused by the malunion of a calcaneal fracture without severe subtalar arthritis. Further prospective studies are needed to test this theory.

Notes

Acknowledgements

The authors would like to thank Editage (https://www.editage.com) for English language editing. The authors would like to thank the Soonchunhyang University Research Fund for support.

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

Funding

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Availability of data and materials

The datasets used and analyzed during the study are available from the corresponding author on reasonable request.

Authors’ contributions

HSL contributed to study conception and design, data collection and analysis, drafting of the article and critical revision of the article. YKL, ESP, and WJK contributed to data collection and analysis and the critical revision of the article. JYK and YHK contributed to editing of the article. All authors read and approved the final manuscript.

Ethics approval and consent to participate

This study was reviewed and approved by the Institutional Review Board of Eulji Medical Center (Approval No. 2018–02-006). We obtained written informed consent from all patients.

Consent for publication

Written consent to publish the content of this report along with the accompanying images was obtained from all patients.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  1. 1.
    Banerjee R, Saltzman C, Anderson RB, Nickisch F. Management of calcaneal malunion. J Am Acad Orthop Surg. 2011;19:27–36.CrossRefGoogle Scholar
  2. 2.
    Eckstein C, Kottmann T, Fuchtmeier B, Muller F. Long-term results of surgically treated calcaneal fractures: an analysis with a minimum follow-up period of twenty years. Int Orthop. 2016;40:365–70.CrossRefGoogle Scholar
  3. 3.
    Nickisch F, Anderson RB. Post-calcaneus fracture reconstruction. Foot Ankle Clin. 2006;11:85–103.CrossRefGoogle Scholar
  4. 4.
    Loucks C, Buckley R. Bohler’s angle: correlation with outcome in displaced intra-articular calcaneal fractures. J Orthop Trauma. 1999;13:554–8.CrossRefGoogle Scholar
  5. 5.
    Csizy M, Buckley R, Tough S, Leighton R, Smith J, McCormack R, Pate G, Petrie D, Galpin R. Displaced intra-articular calcaneal fractures: variables predicting late subtalar fusion. J Orthop Trauma. 2003;17:106–12.CrossRefGoogle Scholar
  6. 6.
    Chung HJ, Bae SY, Choo JW. Mid-term follow up results of subtalar distraction arthrodesis using a double bone-block for calcaneal malunion. Yonsei Med J. 2014;55:1087–94.CrossRefGoogle Scholar
  7. 7.
    Rammelt S, Zwipp H. Corrective arthrodeses and osteotomies for post-traumatic hindfoot malalignment: indications, techniques, results. Int Orthop. 2013;37:1707–17.CrossRefGoogle Scholar
  8. 8.
    Young KW, Lee KT, Lee YK, Jang MS, Yoon JH, Kim JH. Calcaneal reconstruction for the late complication of calcaneus fracture. Orthopedics. 2011;34:e634–8.PubMedGoogle Scholar
  9. 9.
    Stephens HM, Sanders R. Calcaneal malunions: results of a prognostic computed tomography classification system. Foot Ankle Int. 1996;17:395–401.CrossRefGoogle Scholar
  10. 10.
    Zwipp H, Rammelt S. Posttraumatic deformity correction at the foot. Zentralbl Chir. 2003;128:218–26.CrossRefGoogle Scholar
  11. 11.
    Dupont WD, Plummer WD Jr. Power and sample size calculations: a review and computer program. Control Clinical Trials. 1990;11:116–28.CrossRefGoogle Scholar
  12. 12.
    Romash MM. Reconstructive osteotomy of the calcaneus with subtalar arthrodesis for malunited calcaneal fractures. Clin Orthop. 1993;290:157–67.Google Scholar
  13. 13.
    Gotha HE, Zide JR. Current controversies in management of calcaneus fractures. Orthop Clin. 2017;48:91–103.CrossRefGoogle Scholar
  14. 14.
    Ågren PH, Wretenberg P, Sayed-Noor AS. Operative versus nonoperative treatment of displaced intra-articular calcaneal fractures: a prospective, randomized, controlled multicenter trial. J Bone Joint Surg. 2013;95:1351–7.CrossRefGoogle Scholar
  15. 15.
    Brauer CA, Manns BJ, Ko M, Donaldson C, Buckley R. An economic evaluation of operative compared with nonoperative management of displaced intra-articular calcaneal fractures. J Bone Joint Surg. 2005;87:2741–9.CrossRefGoogle Scholar
  16. 16.
    Veltman ES, Doornberg JN, Stufkens SA, Luitse JS, van den Bekerom MP. Long-term outcomes of 1,730 calcaneal fractures: systematic review of the literature. J Foot Ankle Surg. 2013;52:486–90.CrossRefGoogle Scholar
  17. 17.
    Ågren PH, Mukka S, Tullberg T, Wretenberg P, Sayed-Noor AS. Factors affecting long-term treatment results of displaced intraarticular calcaneal fractures: a post hoc analysis of a prospective, randomized, controlled multicenter trial. J Orthop Trauma. 2014;28:564–8.CrossRefGoogle Scholar
  18. 18.
    Radnay CS, Clare MP, Sanders RW. Subtalar fusion after displaced intra-articular calcaneal fractures: does initial operative treatment matter? J Bone Joint Surg. 2009;91:541–6.CrossRefGoogle Scholar
  19. 19.
    Buckley R, Tough S, McCormack R, Pate G, Leighton R, Petrie D, Galpin R. Operative compared with nonoperative treatment of displaced intra-articular calcaneal fractures: a prospective, randomized, controlled multicenter trial. J Bone Joint Surg Am. 2002;84:1733–44.CrossRefGoogle Scholar
  20. 20.
    Rammelt S, Zwipp H. Calcaneus fractures: facts, controversies and recent developments. Injury. 2004;35:443–61.CrossRefGoogle Scholar
  21. 21.
    Savva N, Saxby T. In situ arthrodesis with lateral-wall ostectomy for the sequelae of fracture of the os calcis. J Bone Joint Surg Br. 2007;89:919–24.CrossRefGoogle Scholar
  22. 22.
    Clare MP, Lee WE III, Sanders RW. Intermediate to long-term results of a treatment protocol for calcaneal fracture malunions. J Bone Joint Surg. 2005;87:963–73.CrossRefGoogle Scholar
  23. 23.
    Yu G-R, Hu S-J, Yang Y-F, Zhao H-M, Zhang S-M. Reconstruction of calcaneal fracture malunion with osteotomy and subtalar joint salvage: technique and outcomes. Foot Ankle Int. 2013;34:726–33.CrossRefGoogle Scholar
  24. 24.
    Aronson J, Nunley J, Frankovitch K. Lateral talocalcaneal angle in assessment of subtalar Valgus: follow-up of seventy Grice-green Arthrodeses. Foot Ankle. 1983;4:56–63.CrossRefGoogle Scholar

Copyright information

© The Author(s). 2019

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors and Affiliations

  1. 1.Department of Foot and Ankle Surgery, Eulji Medical CenterEulji UniversitySeoulKorea
  2. 2.Department of Orthopaedic SurgerySoonchunhyang University Hospital CheonanCheonanKorea
  3. 3.Department of Orthopedic Surgery, College of MedicineSoonchunhyang University Bucheon HospitalBucheon-siRepublic of Korea

Personalised recommendations