Minimally Invasive Reduction of Intraarticular Calcaneal Fractures With Percutaneous Fixation Using Cannulated Screws Versus Kirschner Wires: A Retrospective Comparative Study

Abstract

Background

Several minimally invasive techniques were developed for management of intraarticular calcaneal fractures. This study aimed to compare the functional and radiological outcomes of 2 minimally invasive reduction and fixation techniques using cannulated screws or Kirschner wires (K-wires) for fixation.

Methods

This study was a retrospective comparative review of patients with displaced intraarticular calcaneal fractures, who were treated with cannulated screws or K-wires techniques. Clinical and radiological data were collected and compared between both groups. Functional outcomes and patient satisfaction using the Maryland Foot Score (MFS) and the visual analogue scale (VAS) of pain, in addition to the complications, were compared between both groups.

Results

In total, 70 patients were included in the study: 34 in the cannulated screws group, with a mean age of 35.2 ± 4 years, and 36 in the K-wires groups, with a mean age of 33.4 ± 3 years. The operative time was shorter in the K-wires group (40.5 ± 5.6 minutes) compared to the cannulated screw group (49.5 ± 4.5 minutes), P < .001. There were no statistically significant differences between both groups regarding the radiological parameters, including Bohler’s angle, angle of Gissane, calcaneal width, height, or length. The mean MFS, mean VAS, and complications were not different between the 2 groups.

Conclusion

Treatment of displaced intraarticular calcaneal fractures with minimally invasive reduction and fixation using either cannulated screws or K-wires can achieve similar excellent functional and radiological outcomes, with high patient satisfaction. The use of K-wires has the advantage of reduced operative time than cannulated screws.

Levels of Evidence:

Level III: Retrospective comparative study

Keywords

calcaneal fracture minimally invasive percutaneous fixation cannulated screws Kirschner wires comparative study

“The treatment of displaced intraarticular fractures of the calcaneus is challenging and controversial dilemma for most orthopaedic surgeons all over the world.”

Calcaneal fractures are the most frequent tarsal injury, with an overall yearly incidence of 11.5 cases per 100 000 population.¹ These fractures are often occupational due to high-velocity force to the hindfoot, frequently from motor vehicle accidents, or fall from height in young men in their prime working years.^2-5

Nearly 75% of calcaneal fractures are intraarticular, which often require complex surgery to reconstruct the articular surface and lead to considerable long-term disability, placing a substantial economic load on the person and the community.^1,3,6

The treatment of displaced intraarticular fractures of the calcaneus is challenging and controversial dilemma for most orthopaedic surgeons all over the world.^6-9

Conservative management was associated with the persistence of calcaneal deformities, including widening, shortening, peroneal tendons impingement, in addition to nonreduction of the articular surface, leading to impaired functional outcome and disabling pain.^10,11

The fundamental purpose of calcaneal fractures surgical management is to reestablish the volume of the calcaneus and the alignment of the hindfoot to allow a good functional result even if the subtalar is very often rigid.^9,12

Open reduction and internal fixation through the extended lateral approach allows excellent visualization and direct reduction of the articular surface; however, it has been reported to be associated with a high incidence of soft tissue complications.^6,13-15

Recently, several minimally invasive reduction and fixation techniques for intraarticular calcaneal fractures have been developed and are becoming more widespread among the orthopaedic community with the ability to restore the articular surface congruity, and at the same time, avoid soft tissue complications.^16-18

These techniques are technically challenging in achieving anatomic reduction and stable fixation and tend to require indirect reduction, depending on ligamentotaxis and several other maneuvers, including pins, periosteal elevators, laminar spreaders, or bone punches to obtain reduction under the guidance of intraoperative image intensifier.^7,18-20 The accuracy of reduction should be confirmed intraoperatively with image intensifier images, including Broden’s views to evaluate the articular surfaces of the posterior facet and postoperatively by postoperative standard radiographs and computed tomography (CT) scans.¹⁷ Different minimally invasive techniques have been reported and achieved satisfactory outcomes, including percutaneous Kirschner wires (K-wires) or Steinman pins, percutaneous cannulated or solid screws, external fixators, and percutaneous plates.^18,21-25

Previous studies compared the results of percutaneous screw fixation and plate fixation via minimally invasive sinus tarsi approach.^23,26,27 This study attempted to investigate and compare the functional and radiological outcomes and complications of 2 minimally invasive reduction and fixation techniques of Sanders types II and III intraarticular calcaneal fractures using cannulated screws or K-wires for fixation. We hypothesized that both minimally invasive techniques would achieve comparable satisfactory results.

Methods

Patients

We retrospectively reviewed 70 patients with displaced intraarticular fractures of the calcaneus, who were admitted to a single academically supervised level 1 trauma center from June 2013 to March 2017. The institutional review board of our hospital has approved this study. The inclusion criteria were patients with unilateral displaced intraarticular closed fracture of the calcaneus, Sanders type II or III, without any associated injuries, who underwent surgical management with minimally invasive reduction and fixation using either cannulated screws or K-wires. All patients included in this study had to be ≥18 years old, with a minimum follow-up period of 2 years. Patients with a history of severe neurological or vascular deficits, and previous foot fractures or surgery, were excluded.

Surgical Techniques

Both procedures were performed alternatively by a single foot and ankle fellowship–trained surgeon with 5 years of experience. Patients were placed in the lateral decubitus position on a radiolucent operating table under spinal anesthesia, with the affected foot elevated on proper support.

Cannulated Screws Fixation Technique

Bimanual compression was applied to the calcaneus to reduce its width. A small 1- to 2-cm incision was performed beneath the tip of the lateral malleolus; then, a small periosteal elevator was inserted to elevate the depressed articular surface under C-arm guidance. Fracture fragments were fixed provisionally by percutaneous K-wires, followed by insertion of a sustentacular screw, a 4-mm cannulated screw placed directly underneath the articular surface into the sustentaculum tali. After that, a Schanz screw was inserted into the calcaneal tuberosity from lateral to medial to manipulate and correct the heel varus or valgus. Then, two 6.5-mm cannulated screws were inserted from the posterior tuberosity under the elevated articular surface crossing each other. The wounds were sutured, and a padded bandage was applied. Postoperatively, patients began active and passive ankle range of motion exercises as tolerated. Partial weight-bearing began at the 6th postoperative week and full weight-bearing at the 12th week after radiological confirmation of union, Figure 1.

K-Wires Fixation Technique

Bimanual compression across the calcaneus was applied to reduce its width and correct the heel varus or valgus. A Schanz screw was then inserted into the posterior tuberosity, directed forwards and downwards, and then forced downwards to raise the depressed fragment. A small 1- to 2-cm incision was then made below the tip of the lateral malleolus, and a small periosteal elevator was used to restore the articular surface under C-arm guidance. Next, two 2-mm threaded K-wires were inserted parallel to each other from the posteroinferior edge of the calcaneus toward the talar body, transfixing the subtalar joint, and another 2 crossing subchondral K-wires maintained the articular surface, the first one was directed toward the calcaneocuboid joint and the other one was directed toward the calcaneonavicular joint. Eventually, the small incision was sutured, and the K-wires were cut outside the skin, and a posterior splint was applied. Then, the cast and K-wires were removed in the 6th postoperative week, with passive and active ankle range of motion exercises and non-weight-bearing until the 12th postoperative week, after which partial weight-bearing was allowed and progressed gradually until full weight-bearing, Figure 2.

Patient Assessment

Patients were divided into 2 groups according to the type of surgery into cannulated screws group and K-wires group. Data were analyzed and compared between the 2 groups. Data collection included patient characteristics (age, gender), trauma characteristics (mode of trauma, affected side, fracture classification), and treatment characteristics (the type of surgery, duration of surgery, length of hospital stay).

Radiographic Outcome Measures

Radiographic data were collected by analyzing conventional X-rays, including lateral and axial views, in the preoperative, immediate postoperative, and 1.5-month, 3-month, 6-month, 1-year, and 2-year follow-up periods. Preoperative and postoperative Bohler’s and Gissane angles, calcaneal width, height, and length were measured and compared. Follow-up X-rays were observed for bone healing, loss of reduction, and any incidence of arthritis. Preoperative CT scans were used for Sanders classification²⁸ of the fractures, in addition to understanding the fracture pattern, including the main fracture line, the number and size of fragments and their dislocation. Postoperative CT scans were assessed for the accuracy of reduction.

Functional Outcome Measures

The evaluation of the functional outcomes and patient satisfaction using the Maryland Foot Score (MFS),²⁹ and the visual analogue scale (VAS) of pain,³⁰ respectively, were recorded. Finally, the complication rates were recorded and analyzed.

Statistical Analysis

Statistical analysis of data was performed using IBM SPSS version 25.0 (SPSS Inc). The χ² or Fisher’s exact tests were used to compare the categorical variables, while the Student’s t test was used to compare continuous variables. The threshold of statistical significance was set at a P value of less than .05.

Results

Throughout the study period, 233 patients with calcaneal fractures were admitted to our institution. After applying the inclusion and exclusion criteria, 70 patients were included in the study: 34 in the cannulated screws and 36 in the K-wires groups. Their mean ages were 35.2 ± 4 years and 33.4 ± 3 years in the cannulated screws and the K-wires groups, respectively, P = .036. The percentage of male patients was higher in the cannulated screws than the K-wires group, 94.1% and 61.1, respectively, P = .001. The involvement of the right side was more common in the cannulated screws (76.5%) than in the K-wires group (47.2%), P = .012. There was no statistically significant difference between the 2 groups regarding the mechanism of injury, fracture classification, time from trauma to surgery, or hospital stay. However, the operative time was shorter in the K-wires group (40.5 ± 5.6 minutes) than the cannulated screw group (49.5 ± 4.5 minutes), P < .001, Table 1. The mean follow-up period was 30.1 ± 3.8 (range, 26-34) months in the cannulated screws group and 31.4 ± 4.1 (range, 27-36) months in the K-wires group, P = .174.

Table 1.

Demographics and Baseline Characteristics Among the 2 Groups.

Characteristics	Cannulated screws group (n = 34)	K-wires group (n = 36)	P
Age (years)
Mean ± SD	35.2 ± 4	33.4 ± 3	.036
Gender, n (%)
Male	32 (94.1)	22 (61.1)	.001
Female	2 (5.9)	14 (38.9)	.001
Side, n (%)
Right	26 (76.5)	17 (47.2)	.012
Left	8 (23.5)	19 (52.8)	.012
Mechanism of injury, n (%)
Fall from height	30 (88.2)	32 (88.9)	.932
Road traffic accidents	4 (11.8)	4 (11.1)	.932
Sanders classification, n (%)
Type II	26 (76.5)	21 (58.3)	.106
Type III	8 (23.5)	15 (41.7)	.106
Baseline VAS
Mean ± SD	7.2 ± 0.6	7.5 ± 0.8	.0817
Time to surgery (days)
Mean ± SD	3.2 ± 0.9	2.9 ± 0.7	.123
Operative time (minutes)
Mean ± SD	49.5 ± 4.5	40.5 ± 5.6	<.001
Hospital stay (days)
Mean ± SD	1.4 ± 0.3	1.5 ± 0.4	.243

Abbreviation: VAS, visual analogue scale of pain.

Radiological Outcomes

The mean time of radiological evidence of union was 8.5 ± 0.9 weeks in the cannulated screws group and 8.8 ± 1.3 weeks in the K-wires group, P = .268. The mean Bohler’s angle was corrected from 4.3 ± 2.6° and 3.6 ± 2.3° to 28.5 ± 4.2° and 30.1 ± 3.9° in both groups, respectively, P = .103. The mean angle of Gissane was corrected from 149.1 ± 6.2° and 146.7 ± 4.3° to 132.2 ± 7.1° and 129.3 ± 6.7° in both groups, respectively, P = .083, Table 2.

Table 2.

Preoperative and Postoperative Radiographic Parameters in Both Groups.

Characteristics	Cannulated screws group (n = 34), mean ± SD	K-wires group (n = 36), mean ± SD	P
Radiographic solid union (weeks)	8.5 ± 0.9	8.8 ± 1.3	.268
Bohler’s angle (°)
Preoperative	4.3 ± 2.6	3.6 ± 2.3	.236
Postoperative	28.5 ± 4.2	30.1 ± 3.9	.103
Angle of Gissane (°)
Preoperative	149.1 ± 6.2	146.7 ± 4.3	.063
Postoperative	132.2 ± 7.1	129.3 ± 6.7	.083
Calcaneal width (mm)
Preoperative	45.1 ± 3.3	44.1 ± 2.9	.182
Postoperative	34.2 ± 1.9	33.3 ± 3.1	.151
Calcaneal height (mm)
Preoperative	32.6 ± 2.4	31.5 ± 3.3	.117
Postoperative	38.4 ± 2.9	37.3 ± 3.7	.172
Calcaneal length (mm)
Preoperative	62.5 ± 6.1	61.4 ± 5.9	.446
Postoperative	69.3 ± 3.5	67.6 ± 4.2	.071

Functional Outcomes

Good to excellent results were achieved in 33 (97.1%) in the cannulated screws group and in 34 (94.5%) patients in the K-wires group. The mean MFS was comparable in the 2 groups, 89.9 ± 5.9 (range, 70-100) and 87.8 ± 7.5 (range, 65-100) points in the cannulated screws and the K-wires groups, respectively. This difference was statistically nonsignificant, P = .099.

Similarly, there was no significant difference between the 2 groups regarding the follow-up VAS of pain, 0.9 ± 0.6 and 1.2 ± 0.7 in the 2 groups, respectively, P = .059. The mean full weight-bearing time and the mean time of return to work did not differ between the 2 groups, P = .419 and .314.

At the final follow-up, all patients in both groups showed a normal range of motion of the ankle joint (active dorsiflexion and plantar flexion) when compared to the healthy side. The average subtalar range of motion (active inversion and eversion) was equivalent to 80% and 70% of the contralateral healthy foot, in the cannulated screws and K-wires group, respectively.

The overall complication rates were not different between the 2 groups, 8.7% and 8.3%, respectively, P = .942. There were 3 cases of superficial infection, 1 case (2.9%) in the cannulated screws group and 2 cases (5.5%) in the K-wires group, P = .589, and good healing was obtained with continuous dressing, Table 3.

Table 3.

Functional Outcomes in the 2 Groups.

Outcomes	Cannulated screws group (n = 34)	K-wires group (n = 36)	P-value
Maryland Foot Score
Mean ± SD	89.9 ± 5.9	87.8 ± 7.5	.099
Median	91.5	90
Range	70-100	65-100
Results
Excellent, n (%)	28 (82.4)	28 (77.8)
Good, n (%)	5 (14.7)	6 (16.7)
Fair, n (%)	1 (2.9)	2 (5.5)
Poor, n (%)	0 (0)	0 (0)
Follow-up VAS	0.9 ± 0.6	1.2 ± 0.7	.059
Full weight-bearing (weeks)
Mean ± SD	12.6 ± 1.9	12.3 ± 1.1	.419
Return to work (weeks)
Mean ± SD	18.2 ± 1.7	17.8 ± 1.6	.314
Complications
Superficial infection, n (%)	1 (2.9)	2 (5.5)	.589
Heel widening, n (%)	0 (0)	1 (2.8)	—
Tarsal tunnel syndrome, n (%)	1 (2.9)	0 (0)	—
Calcaneocuboid arthritis, n (%)	1 (2.9)	0 (0)	—
Complication rate (%)	8.7	8.3	.942

Abbreviation: VAS, visual analog scale of pain.

Discussion

In the current study, we compared the functional and radiological outcomes following 2 minimally invasive reduction and fixation techniques of Sanders type II and III calcaneal fracture using cannulated screws or K-wires.

According to the MFS recorded during the follow-up period, the mean scores were 89.9 points in the cannulated screws group and 87.8 points in the K-wires group. The overall excellent and good rates between the 2 groups were 97.1% for the cannulated screws group and 94.5% for the K-wires group. No statistically significant difference was detected between the 2 groups, which showed that the 2 minimally invasive methods’ curative impact was comparable. Similarly, there were no significant differences in the follow-up VAS of pain, full weight-bearing time, and return to work time between the 2 groups.

Restoration of Bohler’s angle and angle of Gissane is critical for the anatomical reconstruction of the subtalar joint and restoration of normal calcaneus height and width, influencing the final treatment results.³¹ In the current study, the imaging results showed no statistically significant differences between the 2 groups during follow-up regarding Bohler’s angle, angle of Gissane, calcaneal width, height, or length.

The overall postoperative complication rate did not differ between the 2 groups. The K-wires group had a higher risk of superficial infection (5.5%) compared to a 2.9% rate in the cannulated screws group, although the difference was statistically insignificant. This higher incidence may be justified as the K-wires are cut outside the skin compared to the screws which are concealed inside.

In this study, with a mean follow-up of 30.1 months, the mean MFS in the cannulated screw group was 89.9 points, which was higher than Tomesen et al³² study that reported a mean MFS of 86.4 points after treating 39 displaced intraarticular calcaneal fractures using minimally invasive cannulated screws fixation, with a mean follow-up of 66 months. Also, Tomesen et al³² reported a postoperative wound infection rate of 13% compared to a superficial infection rate of 2.9% in this study. Abdelgaid²² used cannulated screws for fixation and reported a 79.3% rate of satisfactory results with no cases of wound complications or deep infections, with an average follow-up period of 29 months.

In this study, with an average follow-up of 31.4 months, the mean MFS in the K-wires group was 87.8 points, which coincided with Arora et al,³³ who treated 27 intraarticular calcaneal fractures with minimally invasive reduction and percutaneous fixation using K-wires, with a mean MFS of 87.7 points at 26 months follow-up. Arora et al³³ reported no cases of superficial or deep wound infections compared to a 5.5% rate of superficial infection in our study. However, the superficial infection was mild, and good healing was obtained with continuous dressing. Stulik et al³⁴ reported a mean Creighton-Nebraska Health Foundation Assessment score of 83.9 points, following treatment of 247 patients with minimally invasive reduction and K-wires fixation. The reported superficial pin-track infection was 7%, and the deep infection rate was 1.7%.³⁴

Both techniques presented in this study allow sufficient reduction and fixation, with minimal soft tissue insult. In addition to being less expensive, the advantages of using K-wires over cannulated screws include easier insertion, reduced operative time, less soft tissue trauma, minimal heat necrosis, and easy removal in the outpatient clinic.³³ On the other hand, fixation with K-wires requires postoperative cast immobilization due to the lower stability of the fixation with respect to the screws.¹⁸ Cannulated screw fixation has comparable fixation efficacy and functional results as plate fixation, with shorter surgery duration, as well as low complication rate, as concluded by Fan et al³⁵ meta-analysis.

One notable difference between both techniques is that the K-wires pass through the subtalar joint. The direction of the K-wires across the subtalar joint until it sufficiently purchases the body of the talus adds more strength to the stabilization of the fracture fragments in the reduced alignment.³⁶ These wires are temporary and left in situ for 6 weeks, then removed. The subtalar joint crossing by the K-wires to add more stability seems not to disrupt function, mainly because they are temporary and have a small diameter of 2 mm. The screws, on the other hand, keep the reduced fragment stable and act as a raft to support the depressed fragments. Both techniques rely on indirect reduction that demands ample use of fluoroscopy to guarantee accurate anatomic reduction, which remains a significant concern.³⁷

This study has some limitations, including its retrospective nature, the relatively low number of patients with a lack of power, and the relatively short follow-up period to adequately assess subtalar arthritis. However, this study provides an emphasis on the effectiveness of minimally invasive procedures for the management of calcaneal fractures in achieving excellent functional and radiological outcomes with low infection rates. Future follow-up studies may address this topic prospectively using a larger sample size.

Conclusions

Minimally invasive reduction and fixation of displaced intraarticular calcaneal fractures using either cannulated screws or K-wires can achieve comparable excellent functional and radiological outcomes, with high patient satisfaction. The use of K-wires for fixation has the advantage of reduced operative time than cannulated screws.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Ethical Approval

Approval of ethical review committee has been obtained.

Informed Consent

Not applicable.

Trial Registration

Not applicable.

ORCID iD

Mohamed Kamal Mesregah

References

Colak

Polat

Timurtaş

Bulut

Gülabi

. The results of physical, radiologic, pedabarographic, and quality-of-life assessments in patients with surgically treated intraarticular calcaneus fractures. J Foot Ankle Surg. 2018;57:1172-1180.

Galluzzo

Greco

Pietragalla

, et al. Calcaneal fractures: radiological and CT evaluation and classification systems. Acta Biomed. 2018;89:138-150.

Brauer

Manns

Donaldson

Buckley

. An economic evaluation of operative compared with nonoperative management of displaced intra-articular calcaneal fractures. J Bone Joint Surg Am. 2005;87:2741-2749.

Santosha Gulrez

Singh

, et al. Open reduction and internal fixation of displaced calcaneum, intra-articular fractures by locking calcaneal plate. J Clin Diagn Res. 2016;10:RC18-RC21.

White

Skalski

Matcuk

Jr , et al. Intra-articular tongue-type fractures of the calcaneus: anatomy, injury patterns, and an approach to management. Emerg Radiol. 2019;26:67-74.

Buzzi

Sermi

Soviero

Bianco

Campanacci

. Displaced intra-articular fractures of the calcaneus: ORIF through an extended lateral approach. Injury. 2019;50(suppl 2):S2-S7.

Sharr

Mangupli

Winson

Buckley

. Current management options for displaced intra-articular calcaneal fractures: non-operative, ORIF, minimally invasive reduction and fixation or primary ORIF and subtalar arthrodesis. A contemporary review. Foot Ankle Surg. 2016;22:1-8.

Epstein

Chandran

Chou

. Current concepts review: intra-articular fractures of the calcaneus. Foot Ankle Int. 2012;33:79-86.

Takeuchi

Mae

Fukushi

, et al. Management of intra-articular calcaneal fractures: clinical results of reduction technique using a bone spreader. J Foot Ankle Surg. 2017;56:1025-1030.

10.

Pozo

Kirwan

Jackson

. The long-term results of conservative management of severely displaced fractures of the calcaneus. J Bone Joint Surg Br. 1984;66:386-390.

11.

Crosby

Fitzgibbons

. Intraarticular calcaneal fractures. Results of closed treatment. Clin Orthop Relat Res. 1993;(290):47-54.

12.

Guerado

Bertrand

Cano

. Management of calcaneal fractures: what have we learnt over the years? Injury. 2012;43:1640-1650.

13.

Buckley

Leighton

Sanders

, et al. Open reduction and internal fixation compared with ORIF and primary subtalar arthrodesis for treatment of Sanders type IV calcaneal fractures: a randomized multicenter trial. J Orthop Trauma. 2014;28:577-583.

14.

Kiewiet

Sangeorzan

. Calcaneal fracture management: extensile lateral approach versus small incision technique. Foot Ankle Clin. 2017;22:77-91.

15.

Clare

Crawford

. Managing complications of calcaneus fractures. Foot Ankle Clin. 2017;22:105-116.

16.

Pan

Chatterjee

Garg

Mukhopadhyay

Banerjee

Kumar

. Percutaneous fixation of displaced intra-articular calcaneal fracture. J Indian Med Assoc. 2011;109:412-414.

17.

Meraj

Zahid

Ahmad

. Management of intraarticular calcaneal fractures by minimally invasive sinus tarsi approach-early results. Malays Orthop J. 2012;6:13-17.

18.

Mesregah

Shams

Gamal

Zaki

. Clinical and radiological outcomes of minimally invasive reduction and percutaneous K-wire fixation for intra-articular calcaneal fractures. Orthopedics. 2020;43:97-101.

19.

Jin

Weng

Yang

, et al. Minimally invasive percutaneous osteosynthesis versus ORIF for Sanders type II and III calcaneal fractures: a prospective, randomized intervention trial. J Orthop Surg Res. 2017;12:10.

20.

Rammelt

Amlang

Barthel

Gavlik

Zwipp

. Percutaneous treatment of less severe intraarticular calcaneal fractures. Clin Orthop Relat Res. 2010;468:983-990.

21.

Abdelazeem

Khedr

Abousayed

Seifeldin

Khaled

. Management of displaced intra-articular calcaneal fractures using the limited open sinus tarsi approach and fixation by screws only technique. Int Orthop. 2014;38:601-606.

22.

Abdelgaid

. Closed reduction and percutaneous cannulated screws fixation of displaced intra-articular calcaneus fractures. Foot Ankle Surg. 2012;18:164-179.

23.

Feng

Shui

Wang

, et al. Comparison of percutaneous cannulated screw fixation and calcium sulfate cement grafting versus minimally invasive sinus tarsi approach and plate fixation for displaced intra-articular calcaneal fractures: a prospective randomized controlled trial. BMC Musculoskelet Disord. 2016;17:288.

24.

Magnan

Bortolazzi

Marangon

Marino

Dall’Oca

Bartolozzi

. External fixation for displaced intra-articular fractures of the calcaneum. J Bone Joint Surg Br. 2006;88:1474-1479.

25.

Shams

Gamal

Mesregah

. Outcome of minimally invasive osteosynthesis for displaced intra-articular calcaneal fractures using cannulated screws: a prospective case series. J Foot Ankle Surg. 2021;60(1):55-60.

26.

Weng

Dai

, et al. Comparison between percutaneous screw fixation and plate fixation via sinus tarsi approach for calcaneal fractures: an 8-10-year follow-up study. Orthop Surg. 2020;12:124-132.

27.

Kir

Ayanoglu

Cabuk

, et al. Mini-plate fixation via sinus tarsi approach is superior to cannulated screw in intra-articular calcaneal fractures: a prospective randomized study. J Orthop Surg (Hong Kong). 2018;26:2309499018792742.

28.

Sanders

Fortin

DiPasquale

Walling

. Operative treatment in 120 displaced intraarticular calcaneal fractures. Results using a prognostic computed tomography scan classification. Clin Orthop Relat Res. 1993;(290):87-95.

29.

Sanders

. Displaced intra-articular fractures of the calcaneus. J Bone Joint Surg Am. 2000;82:225-250.

30.

Downie

Leatham

Rhind

Wright

Branco

Anderson

. Studies with pain rating scales. Ann Rheum Dis. 1978;37:378-381.

31.

Persson

Peters

Haddadin

O’Loughlin

Krettek

Gaulke

. The prognostic value of radiologic parameters for long-term outcome assessment after an isolated unilateral calcaneus fracture. Technol Health Care. 2015;23:285-298.

32.

Tomesen

Biert

Frolke

. Treatment of displaced intra-articular calcaneal fractures with closed reduction and percutaneous screw fixation. J Bone Joint Surg Am. 2011;93:920-928.

33.

Arora

Jain

Dhammi

. Outcome of percutaneous fixation of calcaneal fractures: a prospective analysis in an Indian population. J Foot Ankle Surg. 2019;58:502-507.

34.

Stulik

Stehlik

Rysavy

Wozniak

. Minimally-invasive treatment of intra-articular fractures of the calcaneum. J Bone Joint Surg Br. 2006;88:1634-1641.

35.

Fan

Zhou

Wei

, et al. Cannulated screw fixation and plate fixation for displaced intra-articular calcaneus fracture: a meta-analysis of randomized controlled trials. Int J Surg. 2016;34:64-72.

36.

Pezzoni

Salvi

Tassi

Bruneo

. A minimally invasive reduction and synthesis method for calcaneal fractures: the “Brixian bridge” technique. J Foot Ankle Surg. 2009;48:85-88.

37.

Rammelt

Zwipp

. Fractures of the calcaneus: current treatment strategies. Acta Chir Orthop Traumatol Cech. 2014;81:177-196.