- Email: [email protected]
Treatment of proximal fifth metatarsal fractures with an ulna hook plate
Journal Pre-proof Treatment of proximal fifth metatarsal fractures with an ulna hook plate Abdullah Ismat, Markus Rupp, Gero Knapp, Christian Heiss, Gabor Szalay, Christoph Biehl
PII:
S0958-2592(19)30199-3
DOI:
https://doi.org/10.1016/j.foot.2019.101653
Reference:
YFOOT 101653
To appear in:
The Foot
Received Date:
28 June 2019
Revised Date:
6 October 2019
Accepted Date:
25 October 2019
Please cite this article as: Ismat A, Rupp M, Knapp G, Heiss C, Szalay G, Biehl C, Treatment of proximal fifth metatarsal fractures with an ulna hook plate, The Foot (2019), doi: https://doi.org/10.1016/j.foot.2019.101653
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier.
Treatment of proximal fifth metatarsal fractures with an ulna hook plate
-p
35392 Giessen
ro
1 Department of Trauma, Hand and Reconstructive Surgery University Hospital Giessen-Marburg GmbH Campus Giessen Rudolf-Buchheim-Str. 7 35392 Giessen Germany 2 Department of Trauma, Hand and Reconstructive Surgery University Hospital Giessen-Marburg GmbH Campus Giessen Rudolf-Buchheim-Str. 7
of
Abdullah Ismat1*, Markus Rupp2, Gero Knapp2, Christian Heiss2, Gabor Szalay2, Christoph Biehl2
re
Germany * Corresponding author
ur na
lP
Abdullah Ismat, MB BCh BAO Department of Trauma, Hand and Reconstructive Surgery University Hospital Giessen-Marburg GmbH Campus Giessen Rudolf-Buchheim-Str. 7 35392 Giessen Germany Email: [email protected]
Highlights:
Treatment with the hook plate has demonstrated adequate and comparable results in
Jo
comparison to other forms of internal fixation methods.
Despite the small cohort size, major complications were noted in a case of a delayed union and a case of a refracture of an old partially healed zone 2 fracture. The hook plate had to be removed in the delayed union case due to impaired healing and infection 9
weeks after initial surgery. In the refracture case, revision surgery was necessary 30 weeks after initial surgery as no radiological evidence of re-fracture healing was evident.
Inpatient hospital-stay and postoperative courses were satisfactory and not prolonged.
This form of fixation was not deemed to be technically difficult by the treating surgeons at our institution. The hook plate fixation method provides added benefits relating to the anatomy and
of
fracture morphology in proximal fifth metatarsal fractures that can prove desirable in
ro
certain cases (e.g. comminuted fractures, small avulsion fractures and osteoporotic
-p
fractures)
re
Introduction:
Fractures of the base of the fifth metatarsal bone present one of the commonest fractures of the
lP
metatarsal bones[1]. Proximal fifth metatarsal fractures result not only from direct trauma to this region but can also be caused by inversion injuries with concomitant plantar flexion[2].
ur na
Classification of proximal fifth metatarsal fractures according to Lawrence differentiates 3 fracture types (Figure 1): tuberosity avulsion fractures (Zone 1), metaphyseal-diaphyseal junction fractures extending into the 4-5th intermetatarsal joint (Zone 2) and proximal diaphyseal
Jo
fractures (Zone 3)[3]. This method of classification is not only significant from an anatomical perspective pertaining to the nature of the blood supply but also from a biomechanical point. Biomechanically, Zone 1 fractures likely correspond to avulsion injuries involving the plantar aponeurosis and the peroneus brevis structures[4]. Anatomically, the nature of the blood supply to the proximal fifth metatarsal renders zone 3 fractures prone to poor healing and subsequent non-union[5].
Non-displaced zone 1 fractures may be treated conservatively. However, displaced fractures and intra-articular fractures involving more than 30 % of the articulation of the cubo-metatarsal jointline necessitate surgical intervention[6]. Operative management is recommended in zone 1 fractures with a displacement of more than 3 mm[7]. As for zone 2 fractures, operative intervention is recommended in displaced fractures with further specifications being related to the corresponding Torg classification[8].
of
Several studies have demonstrated that surgical intervention through screw fixation of zone 2
ro
fractures leads to quicker return to activities with improvement in healing time and an earlier
from screw irritation and failure do still occur.
-p
evidence of union[9-11]. Although complications like nonunion, refractures and ones arising
re
Current treatment options are based on the specific fracture type of the proximal fifth metatarsal. Conventionally intramedullary screws have been used as a fixation method for fractures needing
lP
surgical intervention. Additionally, tension band wiring has also been shown to be adequate in certain zone 2 fractures[12]. Lately hook plates have also served as an alternative fixation
ur na
method and have been advocated for certain fracture patterns that might be difficult to adequately reduce using conventional fixation methods. To date several studies have been published reporting on the efficacy of the hook plates[13, 14] and plate fixation[15]. So far promising results have been reported using this form of
Jo
osteosynthesis. In order to further explore and assess this potentially innovative form of surgical treatment, the ulna hook plate LOQTEQ® 2,5mm from manufacturer Aap Implantate AG, Berlin, Germany (Aap), which was originally generated for stabilizing distal ulna fractures, was used in our department to stabilise fractures of the proximal fifth metatarsal (particularly zones 1 & 2 fractures) as appropriate. The objective of this case series was to retrospectively assess this form
of internal fixation as a surgical treatment method of proximal fifth metatarsal fractures needing surgical intervention. Within the scope of this study, we further set out to examine whether the added feature of angle-stable plate osteosynthesis achievable with the LOQTEQ® ulna hook plate is of benefit to fracture healing of proximal fifth metatarsal fractures as evident clinically and radiologically throughout follow-up. The results from this single-center retrospective case series will also be compared to relevant case series and studies reporting not only on hook plate
of
fixation but also on other conventional forms of internal fixation of proximal fifth metatarsal
lP
re
-p
ro
fractures.
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Figure 1: Illustration of the fracture zones of proximal fifth metatarsal bone fractures in accordance to Lawrence classification [2].
Methods:
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21 patients treated with an ulna hook plate, LOQTEQ® 2,5mm from manufacturer Aap, for fractures of the proximal fifth metatarsal bone from September 2015 to September 2017 were retrospectively analysed.
Different parameters relating to aetiology, fracture morphology, post-operative course, return to activities of daily living (ADLs), pre- and postoperative AOFAS midfoot scores were recorded and documented over the course of treatment. Surgical intervention: Patients were operated on in the supine position after induction of anaesthesia. After sterile draping and prepping of the surgical site, a 3-5 cm long longitudinal incision was carried out on
of
the lateral border of the fifth metatarsal bone. Dissection was performed, fracture site was
ro
identified and debrided. Fixation of the fracture with the hook plate was then performed after anatomical reduction. Positioning and fracture reduction were controlled with intra-operative x-
-p
ray imaging after application of the plate and screws (Figure 2). Operative intervention was then
re
completed after layered skin and subcutaneous tissue closure and application of sterile swabs and a bandage.
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The post-operative course and protocol consisted of non-weightbearing and crutches for 6 weeks with thromboembolic prophylaxis following surgery supported by a cast for the first 2 weeks
ur na
until completed wound healing. All patients were followed up regularly up to 12 months postoperatively. Return to activities of daily living (ADLs) was recorded. Complications were noted down and corresponding re-surgeries relating not only to complications but also for elective hardware removal after completed consolidation were documented.
Jo
Microsoft® Excel® 2016 was used for statistical analysis. Paired t test was used to statistically test for significance between preoperative and postoperative AOFAS scores with a p-value of < 0.05 being significant. Regression analysis for correlation between time to surgery and time to union and between time to surgery and return to ADLs was also performed and a p-value of < 0.05 was considered as significant.
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Figure 2: X-ray image demonstrating adequate hook plate fixation of a displaced right-sided
re
reduction is possible through dynamic compression.
-p
zone 1 fifth metatarsal fracture. The fracture line is not visible postoperatively as an anatomical
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Results:
A total of 21 patients, 13 females and 8 males, treated from September 2015 to September 2017
ur na
with an average age of 38.7 years at time of injury (range 19 - 72) were assessed. Of the 21 injuries, 13 were right-sided and 8 were left-sided. 19 patients reported twisting injury to the ankle on the affected side. 1 patient presented with a crush injury through a car rolling over the foot and another patient received a kick to the foot. Radiologically, 11 fractures were zone 1
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fractures, 8 in zone 2 and 2 in zone 3.
2 of the 21 patients presented with and were operated on for non-healed fracture in form of a zone 1 fracture with a non-union (left-sided) and a zone 3 fracture with a delayed union (rightsided) respectively. One patient was surgically treated for a refracture of a 1 month old partially healed zone 2 fracture. Average time from injury to surgery was 23 days (range 3 - 224), of
which the average time to surgery involving primarily treated fracture, excluding the 2 initially non-healed fractures at presentation, was 6.7 days (range 3 - 13). Average duration of hospital-stay after surgery for inpatients (n=19) was 2.3 days (range 1 – 5). 2 patients were operated on as a day-case ambulant surgery and discharged on the same day. Average time to union evident radiologically in primarily treated fractures (n=18) was 7.7 weeks (range 4.5-16 weeks) (Table 1).
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Of the 2 non-healed fractures (1 non-union and 1 delayed union) on initial presentation, 1 patient
ro
with the non-union demonstrated union at 9 weeks and the other patient presenting with the
delayed union failed to demonstrate any evidence of union on x-rays even after 17 weeks after
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early removal of the hook plate 9 weeks after initial surgery due to impaired healing and
re
infection. The patient presenting with a refracture (n=1) continued to not show radiological evidence of consolidation for up to 30 weeks after initial surgery, thereby necessitating a revision
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surgery consisting of hardware removal and bicortical screw placement with tension band wiring and spongioplasty 31 weeks after initial presentation.
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Average time to return of ADLs for all patients (n=21) was 10.3 weeks (range 4.5-37 weeks). Average time to return of ADLs for the primarily surgically treated group (n=18) was 8.1 weeks (range 4.5-21 weeks).
The average AOFAS midfoot score for all the patients (n=21) was 30.4 (range 14-90)
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preoperatively and 95.2 (range 68-100) postoperatively (p<0.01). The average AOFAS midfoot score for the primarily surgically treated group (n=18) was 31 (range 14-90) preoperatively and 97.8 (range 80-100) postoperatively (p<0.01). On regression analysis for correlation between time to surgery and time to union as well as between time to surgery and return to ADLs in the primarily surgically treated fracture group on
presentation (n=18) no statistical significance was evident with p-values of 0.95 and 0.5 respectively. Regarding complications, 1 of the 2 patients presenting with an old partially healed fracture developed impaired wound healing and recurrent non-union necessitating revision surgery and subsequent hardware removal. Another patient reported persistent intermittent pain when fully weight bearing up to 4 months after surgery.
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Elective revision surgery for hardware removal was performed in 12 patients (57%) at a mean
ro
time of 46.6 weeks after initial surgery (range 9-78 weeks).
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Discussion:
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Based on our experience so far and the presented findings, the hook plate as a form of osteosynthesis in proximal fifth metatarsal fractures provides excellent results clinically and
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radiologically. This was particularly evident in cases where it was used in the primarily surgically treated fracture group on presentation (n=18).
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Although in cases of patients presenting with old conservatively treated fractures that failed to heal adequately, the hook plate did not demonstrate good outcomes (n=2). However, this unsatisfying result in primary conservatively treated patients should be proven in larger prospective randomized trials. Sarimo et al. reported satisfactory outcomes after tension-band
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wiring in cases where surgical fixation was performed 6 weeks or longer after initial time of injury in zone 2 fractures [12]. The superiority of tension-band osteosynthesis, as a delayed surgical treatment option in cases where conservative treatment has failed particularly in zone 1 fractures, should be examined and assessed in studies with a higher level of evidence.
Surgical intervention by means of intramedullary screw fixation used in treating proximal fifth metatarsal fractures, in comparison to conservative treatment, was shown to be associated with better outcomes not only in the acute setting but also in the treatment of delayed unions[9]. Furthermore, surgical intervention has also been shown to accelerate time to union and reduce rates of reported non-unions[10, 11]. Time to union and return to ADL’s with screw fixation performed in 19 patients were reported to be 7.5 and 8.0 weeks, respectively[11]. In comparison
of
with outcomes from screw fixation, time to union and return to ADL’s in our patients which
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were treated primarily with the hook plate (n=18), were 7.7 and 8.1 weeks, respectively.
When implementing screw fixation to surgically treat proximal fifth metatarsal fractures, use of
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screws with diameters of more than 4.5 mm has been recommended based on radiological
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anatomical analysis of the fifth metatarsal bone[16]. Adequate fixation of comminuted fractures and small avulsion fractures can be difficult to achieve using screw fixation.
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In a retrospective comparative study, use of hook plates to surgically treat proximal fifth metatarsal fracture has been shown to be advantageous and associated with better outcomes in
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comparison to screw fixation [17]. The significance of these results is however limited by the retrospective nature of this comparative study and its cohort size. Improvement in the time to full and partial weight-bearing was reported after use of hook plate fixation as opposed to screw fixation[17]. Longer periods of non-weight bearing over the course
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of treatment of proximal fifth metatarsal fractures have been associated with poor outcomes[18]. Moreover, the design of hook plates provides better fixation particularly in displaced zone 1 avulsion fractures owing to its morphological suitably to the anatomical particularities of the proximal fifth metatarsal bone and has also been advocated for comminuted and osteoporotic fractures[14]. Furthermore, based on our experience so far, no technical difficulties were
experienced intraoperatively during the performance of hook plate fixation of proximal fifth metatarsal bone fractures using the ulna hook plate. These additional benefits can make up for the higher costs associated with the use of hook plates in comparison to other fixation methods. On the other hand, the higher costs, potentially prolongated intraoperative time and need for revision surgery for hardware removal present unfavourable aspects associated with this form of treatment.
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In this cohort of patients, elective hardware removal was performed in 57 % of cases after hook
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plate fixation. The indication for hardware removal was mainly based on patient’s wishes and not due to any complications in most of these patients (83.3 %). Hardware removal was
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necessary in one case because of impaired wound healing and infection, as already mentioned,
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and in another case due to local irritation from the plate.
With regards to revision surgery after screw fixation, Furia et al. reported a revision rate of 45%
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for hardware removal following screw fixation [19]. Another study presenting results after screw fixation in a total of 19 patients, reported a screw removal rate in 16 % of cases [11]. The higher
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revision rate needed for hardware removal after hook plate osteosynthesis should be taken into account when considering this treatment modality. However, the reported revision rates after different surgical fixation methods are limited to studies reporting on small cohort sizes and should therefore be further examined in larger prospective studies.
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Regarding the results and post-operative outcomes mentioned in the literature pertaining to the hook plate, one study reported an average time to union of 54 days and 74 days mean time to return to ADL’s with average AOFAS midfoot scores of 48 points preoperatively and 91 points postoperatively[13]. In our study, times to union and return to ADL’s were 53.9 and 57 days in
the primarily surgically treated group (n=18) respectively and average AOFAS midfoot scores were 31 points preoperatively and 97.8 points postoperatively in this group (n=18). Another study reporting on its results after hook plates, reported an average time to union of 7.4 weeks and average AOFAS midfoot scores at 26 points preoperatively and 94 points postoperatively[14]. Our results are comparable to the available literature so far reporting on the hook plate’s
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application in proximal fifth metatarsal fractures[13, 14]. However, this study is limited by its
ro
retrospective nature and, like other available studies in the literature, by its small cohort size. Further studies with larger patient cohorts are needed to further outline outcomes from this
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method of osteosynthesis and further additional works comparing the hook plate fixation to other
re
conventional surgical fixation methods, including screw and tension band-wiring, not only
Conclusion:
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clinically but also biomechanically are warranted.
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The use of the ulna hook plate seems to be suitable and adequate as an osteosynthesis method to primarily treat proximal fifth metatarsal fractures requiring surgical intervention with satisfactory post-operative outcomes. Nevertheless, larger prospective comparative studies comparing this
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method of osteosynthesis with other forms of internal fixation are warranted.
Funding:
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors
Conflict of Interest Statement:
The authors declare that there is no conflict of interest
Ethical statement:
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This study was approved by the institutional ethics committee
References 1.
SA, M., Non-united fifth metatarsal metaphyseal fractures. The Foot, 2001. 11(2): p. 99-102.
2.
Lawrence SJ, B.M., Jones' fractures and related fractures of the proximal fifth metatarsal. Foot Ankle, 1993. 14(6): p. 358-65.
3.
Cheung, C.N. and T.H. Lui, Proximal Fifth Metatarsal Fractures: Anatomy, Classification, Treatment and Complications. . Archives of Trauma Research, 2016. 5(4): p. -. Theodorou, D.J., et al., Fractures of Proximal Portion of Fifth Metatarsal Bone: Anatomic and
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4.
ro
Imaging Evidence of a Pathogenesis of Avulsion of the Plantar Aponeurosis and the Short Peroneal Muscle Tendon. Radiology, 2003. 226(3): p. 857-865.
Smith, J.W., S.P. Arnoczky, and A. Hersh, The Intraosseous Blood Supply of the Fifth Metatarsal:
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5.
Implications for Proximal Fracture Healing. Foot Ankle, 1992. 13(3): p. 143-152. Strayer SM, R.S., Petrizzi MJ, Fractures of the proximal fifth metatarsal. American Family
7.
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Physician 1999. 59(9): p. 2516-22.
re
6.
Bowes, J. and R. Buckley, Fifth metatarsal fractures and current treatment. World journal of orthopedics, 2016. 7(12): p. 793-800.
Zwitser, E.W. and R.S. Breederveld, Fractures of the fifth metatarsal; diagnosis and treatment.
ur na
8.
Injury, 2010. 41(6): p. 555-562. 9.
Roche, A.J. and J.D.F. Calder, Treatment and return to sport following a Jones fracture of the fifth
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metatarsal: a systematic review. Knee Surgery, Sports Traumatology, Arthroscopy 2013. 21(6): p. 1307-1315. 10.
Yates, J., et al., Jones fracture of the fifth metatarsal: Is operative intervention justified? A systematic review of the literature and meta-analysis of results. The Foot, 2015. 25(4): p. 251257.
11.
Mologne, T.S., et al., Early Screw Fixation versus Casting in the Treatment of Acute Jones Fractures. The American Journal of Sports Medicine, 2005. 33(7): p. 970-975.
12.
Sarimo, J., et al., Tension-Band Wiring for Fractures of the Fifth Metatarsal Located in the Junction of the Proximal Metaphysis and Diaphysis. The American Journal of Sports Medicine, 2006. 34(3): p. 476-480.
13.
Choi J, L.K., Lee Y, Lee J, Kim H, Surgical Results of Zones I and II Fifth Metatarsal Base Fractures
Lee, S.K., J.S. Park, and W.S. Choy, Locking Compression Plate Distal Ulna Hook Plate as
ro
14.
of
Using Hook Plates. Orthopedics, 2013. 36: p. e71-e74.
Alternative Fixation for Fifth Metatarsal Base Fracture. The Journal of Foot and Ankle Surgery,
15.
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2014. 53(5): p. 522-528.
Kadar, A., et al., Plate Fixation of Proximal Fifth Metatarsal Fracture. Journal of the American
Ochenjele, G., et al., Radiographic Study of the Fifth Metatarsal for Optimal Intramedullary
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16.
re
Podiatric Medical Association, 2015. 105(5): p. 389-394.
Screw Fixation of Jones Fracture. Foot & Ankle International, 2015. 36(3): p. 293-301. 17.
Xie, L., et al., Locking compression plate distal ulna hook plate fixation versus intramedullary
ur na
screw fixation for displaced avulsion fifth Metatarsal Base fractures: a comparative retrospective cohort study. BMC Musculoskeletal Disorders, 2017. 18(1): p. 405. 18.
Vorlat, P., W. Achtergael, and P. Haentjens, Predictors of outcome of non-displaced fractures of
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the base of the fifth metatarsal. International orthopaedics, 2007. 31(1): p. 5-10. 19.
Furia, J.P., et al., Shock Wave Therapy Compared with Intramedullary Screw Fixation for Nonunion of Proximal Fifth Metatarsal Metaphyseal-Diaphyseal Fractures. JBJS, 2010. 92(4): p. 846-854.
Table 1: Results after treatment of proximal fifth metatarsal fractures with hook plate osteosynthesis.
Table 1 (results)
patients
fractures
n = 21
n = 18
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Primarily surgically treated
(8/13)
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Gender
Total number of
(male/female) 38.7 (19-72)
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Age
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in years -
Time from
23 (3-224)
injury to
-
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surgery in days
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average (range)
average (range) Time to union
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in weeks -
7.7 (4.5-16)
average (range) Time to return of ADLs in weeks -
10.3 (4.5-37)
8.1 (4.5-21)
Average (range) Preoperative
30.4 (14-90)
31 (14-90)
95.2 (68-100)
97.8 (80-100)
AOFAS midfoot score -
Postoperative
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average (range)
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AOFAS midfoot score -
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ur na
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re
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average (range)
PII:
S0958-2592(19)30199-3
DOI:
https://doi.org/10.1016/j.foot.2019.101653
Reference:
YFOOT 101653
To appear in:
The Foot
Received Date:
28 June 2019
Revised Date:
6 October 2019
Accepted Date:
25 October 2019
Please cite this article as: Ismat A, Rupp M, Knapp G, Heiss C, Szalay G, Biehl C, Treatment of proximal fifth metatarsal fractures with an ulna hook plate, The Foot (2019), doi: https://doi.org/10.1016/j.foot.2019.101653
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier.
Treatment of proximal fifth metatarsal fractures with an ulna hook plate
-p
35392 Giessen
ro
1 Department of Trauma, Hand and Reconstructive Surgery University Hospital Giessen-Marburg GmbH Campus Giessen Rudolf-Buchheim-Str. 7 35392 Giessen Germany 2 Department of Trauma, Hand and Reconstructive Surgery University Hospital Giessen-Marburg GmbH Campus Giessen Rudolf-Buchheim-Str. 7
of
Abdullah Ismat1*, Markus Rupp2, Gero Knapp2, Christian Heiss2, Gabor Szalay2, Christoph Biehl2
re
Germany * Corresponding author
ur na
lP
Abdullah Ismat, MB BCh BAO Department of Trauma, Hand and Reconstructive Surgery University Hospital Giessen-Marburg GmbH Campus Giessen Rudolf-Buchheim-Str. 7 35392 Giessen Germany Email: [email protected]
Highlights:
Treatment with the hook plate has demonstrated adequate and comparable results in
Jo
comparison to other forms of internal fixation methods.
Despite the small cohort size, major complications were noted in a case of a delayed union and a case of a refracture of an old partially healed zone 2 fracture. The hook plate had to be removed in the delayed union case due to impaired healing and infection 9
weeks after initial surgery. In the refracture case, revision surgery was necessary 30 weeks after initial surgery as no radiological evidence of re-fracture healing was evident.
Inpatient hospital-stay and postoperative courses were satisfactory and not prolonged.
This form of fixation was not deemed to be technically difficult by the treating surgeons at our institution. The hook plate fixation method provides added benefits relating to the anatomy and
of
fracture morphology in proximal fifth metatarsal fractures that can prove desirable in
ro
certain cases (e.g. comminuted fractures, small avulsion fractures and osteoporotic
-p
fractures)
re
Introduction:
Fractures of the base of the fifth metatarsal bone present one of the commonest fractures of the
lP
metatarsal bones[1]. Proximal fifth metatarsal fractures result not only from direct trauma to this region but can also be caused by inversion injuries with concomitant plantar flexion[2].
ur na
Classification of proximal fifth metatarsal fractures according to Lawrence differentiates 3 fracture types (Figure 1): tuberosity avulsion fractures (Zone 1), metaphyseal-diaphyseal junction fractures extending into the 4-5th intermetatarsal joint (Zone 2) and proximal diaphyseal
Jo
fractures (Zone 3)[3]. This method of classification is not only significant from an anatomical perspective pertaining to the nature of the blood supply but also from a biomechanical point. Biomechanically, Zone 1 fractures likely correspond to avulsion injuries involving the plantar aponeurosis and the peroneus brevis structures[4]. Anatomically, the nature of the blood supply to the proximal fifth metatarsal renders zone 3 fractures prone to poor healing and subsequent non-union[5].
Non-displaced zone 1 fractures may be treated conservatively. However, displaced fractures and intra-articular fractures involving more than 30 % of the articulation of the cubo-metatarsal jointline necessitate surgical intervention[6]. Operative management is recommended in zone 1 fractures with a displacement of more than 3 mm[7]. As for zone 2 fractures, operative intervention is recommended in displaced fractures with further specifications being related to the corresponding Torg classification[8].
of
Several studies have demonstrated that surgical intervention through screw fixation of zone 2
ro
fractures leads to quicker return to activities with improvement in healing time and an earlier
from screw irritation and failure do still occur.
-p
evidence of union[9-11]. Although complications like nonunion, refractures and ones arising
re
Current treatment options are based on the specific fracture type of the proximal fifth metatarsal. Conventionally intramedullary screws have been used as a fixation method for fractures needing
lP
surgical intervention. Additionally, tension band wiring has also been shown to be adequate in certain zone 2 fractures[12]. Lately hook plates have also served as an alternative fixation
ur na
method and have been advocated for certain fracture patterns that might be difficult to adequately reduce using conventional fixation methods. To date several studies have been published reporting on the efficacy of the hook plates[13, 14] and plate fixation[15]. So far promising results have been reported using this form of
Jo
osteosynthesis. In order to further explore and assess this potentially innovative form of surgical treatment, the ulna hook plate LOQTEQ® 2,5mm from manufacturer Aap Implantate AG, Berlin, Germany (Aap), which was originally generated for stabilizing distal ulna fractures, was used in our department to stabilise fractures of the proximal fifth metatarsal (particularly zones 1 & 2 fractures) as appropriate. The objective of this case series was to retrospectively assess this form
of internal fixation as a surgical treatment method of proximal fifth metatarsal fractures needing surgical intervention. Within the scope of this study, we further set out to examine whether the added feature of angle-stable plate osteosynthesis achievable with the LOQTEQ® ulna hook plate is of benefit to fracture healing of proximal fifth metatarsal fractures as evident clinically and radiologically throughout follow-up. The results from this single-center retrospective case series will also be compared to relevant case series and studies reporting not only on hook plate
of
fixation but also on other conventional forms of internal fixation of proximal fifth metatarsal
lP
re
-p
ro
fractures.
ur na
Figure 1: Illustration of the fracture zones of proximal fifth metatarsal bone fractures in accordance to Lawrence classification [2].
Methods:
Jo
21 patients treated with an ulna hook plate, LOQTEQ® 2,5mm from manufacturer Aap, for fractures of the proximal fifth metatarsal bone from September 2015 to September 2017 were retrospectively analysed.
Different parameters relating to aetiology, fracture morphology, post-operative course, return to activities of daily living (ADLs), pre- and postoperative AOFAS midfoot scores were recorded and documented over the course of treatment. Surgical intervention: Patients were operated on in the supine position after induction of anaesthesia. After sterile draping and prepping of the surgical site, a 3-5 cm long longitudinal incision was carried out on
of
the lateral border of the fifth metatarsal bone. Dissection was performed, fracture site was
ro
identified and debrided. Fixation of the fracture with the hook plate was then performed after anatomical reduction. Positioning and fracture reduction were controlled with intra-operative x-
-p
ray imaging after application of the plate and screws (Figure 2). Operative intervention was then
re
completed after layered skin and subcutaneous tissue closure and application of sterile swabs and a bandage.
lP
The post-operative course and protocol consisted of non-weightbearing and crutches for 6 weeks with thromboembolic prophylaxis following surgery supported by a cast for the first 2 weeks
ur na
until completed wound healing. All patients were followed up regularly up to 12 months postoperatively. Return to activities of daily living (ADLs) was recorded. Complications were noted down and corresponding re-surgeries relating not only to complications but also for elective hardware removal after completed consolidation were documented.
Jo
Microsoft® Excel® 2016 was used for statistical analysis. Paired t test was used to statistically test for significance between preoperative and postoperative AOFAS scores with a p-value of < 0.05 being significant. Regression analysis for correlation between time to surgery and time to union and between time to surgery and return to ADLs was also performed and a p-value of < 0.05 was considered as significant.
of ro
Figure 2: X-ray image demonstrating adequate hook plate fixation of a displaced right-sided
re
reduction is possible through dynamic compression.
-p
zone 1 fifth metatarsal fracture. The fracture line is not visible postoperatively as an anatomical
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Results:
A total of 21 patients, 13 females and 8 males, treated from September 2015 to September 2017
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with an average age of 38.7 years at time of injury (range 19 - 72) were assessed. Of the 21 injuries, 13 were right-sided and 8 were left-sided. 19 patients reported twisting injury to the ankle on the affected side. 1 patient presented with a crush injury through a car rolling over the foot and another patient received a kick to the foot. Radiologically, 11 fractures were zone 1
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fractures, 8 in zone 2 and 2 in zone 3.
2 of the 21 patients presented with and were operated on for non-healed fracture in form of a zone 1 fracture with a non-union (left-sided) and a zone 3 fracture with a delayed union (rightsided) respectively. One patient was surgically treated for a refracture of a 1 month old partially healed zone 2 fracture. Average time from injury to surgery was 23 days (range 3 - 224), of
which the average time to surgery involving primarily treated fracture, excluding the 2 initially non-healed fractures at presentation, was 6.7 days (range 3 - 13). Average duration of hospital-stay after surgery for inpatients (n=19) was 2.3 days (range 1 – 5). 2 patients were operated on as a day-case ambulant surgery and discharged on the same day. Average time to union evident radiologically in primarily treated fractures (n=18) was 7.7 weeks (range 4.5-16 weeks) (Table 1).
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Of the 2 non-healed fractures (1 non-union and 1 delayed union) on initial presentation, 1 patient
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with the non-union demonstrated union at 9 weeks and the other patient presenting with the
delayed union failed to demonstrate any evidence of union on x-rays even after 17 weeks after
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early removal of the hook plate 9 weeks after initial surgery due to impaired healing and
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infection. The patient presenting with a refracture (n=1) continued to not show radiological evidence of consolidation for up to 30 weeks after initial surgery, thereby necessitating a revision
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surgery consisting of hardware removal and bicortical screw placement with tension band wiring and spongioplasty 31 weeks after initial presentation.
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Average time to return of ADLs for all patients (n=21) was 10.3 weeks (range 4.5-37 weeks). Average time to return of ADLs for the primarily surgically treated group (n=18) was 8.1 weeks (range 4.5-21 weeks).
The average AOFAS midfoot score for all the patients (n=21) was 30.4 (range 14-90)
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preoperatively and 95.2 (range 68-100) postoperatively (p<0.01). The average AOFAS midfoot score for the primarily surgically treated group (n=18) was 31 (range 14-90) preoperatively and 97.8 (range 80-100) postoperatively (p<0.01). On regression analysis for correlation between time to surgery and time to union as well as between time to surgery and return to ADLs in the primarily surgically treated fracture group on
presentation (n=18) no statistical significance was evident with p-values of 0.95 and 0.5 respectively. Regarding complications, 1 of the 2 patients presenting with an old partially healed fracture developed impaired wound healing and recurrent non-union necessitating revision surgery and subsequent hardware removal. Another patient reported persistent intermittent pain when fully weight bearing up to 4 months after surgery.
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Elective revision surgery for hardware removal was performed in 12 patients (57%) at a mean
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time of 46.6 weeks after initial surgery (range 9-78 weeks).
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Discussion:
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Based on our experience so far and the presented findings, the hook plate as a form of osteosynthesis in proximal fifth metatarsal fractures provides excellent results clinically and
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radiologically. This was particularly evident in cases where it was used in the primarily surgically treated fracture group on presentation (n=18).
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Although in cases of patients presenting with old conservatively treated fractures that failed to heal adequately, the hook plate did not demonstrate good outcomes (n=2). However, this unsatisfying result in primary conservatively treated patients should be proven in larger prospective randomized trials. Sarimo et al. reported satisfactory outcomes after tension-band
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wiring in cases where surgical fixation was performed 6 weeks or longer after initial time of injury in zone 2 fractures [12]. The superiority of tension-band osteosynthesis, as a delayed surgical treatment option in cases where conservative treatment has failed particularly in zone 1 fractures, should be examined and assessed in studies with a higher level of evidence.
Surgical intervention by means of intramedullary screw fixation used in treating proximal fifth metatarsal fractures, in comparison to conservative treatment, was shown to be associated with better outcomes not only in the acute setting but also in the treatment of delayed unions[9]. Furthermore, surgical intervention has also been shown to accelerate time to union and reduce rates of reported non-unions[10, 11]. Time to union and return to ADL’s with screw fixation performed in 19 patients were reported to be 7.5 and 8.0 weeks, respectively[11]. In comparison
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with outcomes from screw fixation, time to union and return to ADL’s in our patients which
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were treated primarily with the hook plate (n=18), were 7.7 and 8.1 weeks, respectively.
When implementing screw fixation to surgically treat proximal fifth metatarsal fractures, use of
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screws with diameters of more than 4.5 mm has been recommended based on radiological
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anatomical analysis of the fifth metatarsal bone[16]. Adequate fixation of comminuted fractures and small avulsion fractures can be difficult to achieve using screw fixation.
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In a retrospective comparative study, use of hook plates to surgically treat proximal fifth metatarsal fracture has been shown to be advantageous and associated with better outcomes in
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comparison to screw fixation [17]. The significance of these results is however limited by the retrospective nature of this comparative study and its cohort size. Improvement in the time to full and partial weight-bearing was reported after use of hook plate fixation as opposed to screw fixation[17]. Longer periods of non-weight bearing over the course
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of treatment of proximal fifth metatarsal fractures have been associated with poor outcomes[18]. Moreover, the design of hook plates provides better fixation particularly in displaced zone 1 avulsion fractures owing to its morphological suitably to the anatomical particularities of the proximal fifth metatarsal bone and has also been advocated for comminuted and osteoporotic fractures[14]. Furthermore, based on our experience so far, no technical difficulties were
experienced intraoperatively during the performance of hook plate fixation of proximal fifth metatarsal bone fractures using the ulna hook plate. These additional benefits can make up for the higher costs associated with the use of hook plates in comparison to other fixation methods. On the other hand, the higher costs, potentially prolongated intraoperative time and need for revision surgery for hardware removal present unfavourable aspects associated with this form of treatment.
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In this cohort of patients, elective hardware removal was performed in 57 % of cases after hook
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plate fixation. The indication for hardware removal was mainly based on patient’s wishes and not due to any complications in most of these patients (83.3 %). Hardware removal was
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necessary in one case because of impaired wound healing and infection, as already mentioned,
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and in another case due to local irritation from the plate.
With regards to revision surgery after screw fixation, Furia et al. reported a revision rate of 45%
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for hardware removal following screw fixation [19]. Another study presenting results after screw fixation in a total of 19 patients, reported a screw removal rate in 16 % of cases [11]. The higher
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revision rate needed for hardware removal after hook plate osteosynthesis should be taken into account when considering this treatment modality. However, the reported revision rates after different surgical fixation methods are limited to studies reporting on small cohort sizes and should therefore be further examined in larger prospective studies.
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Regarding the results and post-operative outcomes mentioned in the literature pertaining to the hook plate, one study reported an average time to union of 54 days and 74 days mean time to return to ADL’s with average AOFAS midfoot scores of 48 points preoperatively and 91 points postoperatively[13]. In our study, times to union and return to ADL’s were 53.9 and 57 days in
the primarily surgically treated group (n=18) respectively and average AOFAS midfoot scores were 31 points preoperatively and 97.8 points postoperatively in this group (n=18). Another study reporting on its results after hook plates, reported an average time to union of 7.4 weeks and average AOFAS midfoot scores at 26 points preoperatively and 94 points postoperatively[14]. Our results are comparable to the available literature so far reporting on the hook plate’s
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application in proximal fifth metatarsal fractures[13, 14]. However, this study is limited by its
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retrospective nature and, like other available studies in the literature, by its small cohort size. Further studies with larger patient cohorts are needed to further outline outcomes from this
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method of osteosynthesis and further additional works comparing the hook plate fixation to other
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conventional surgical fixation methods, including screw and tension band-wiring, not only
Conclusion:
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clinically but also biomechanically are warranted.
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The use of the ulna hook plate seems to be suitable and adequate as an osteosynthesis method to primarily treat proximal fifth metatarsal fractures requiring surgical intervention with satisfactory post-operative outcomes. Nevertheless, larger prospective comparative studies comparing this
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method of osteosynthesis with other forms of internal fixation are warranted.
Funding:
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors
Conflict of Interest Statement:
The authors declare that there is no conflict of interest
Ethical statement:
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This study was approved by the institutional ethics committee
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Smith, J.W., S.P. Arnoczky, and A. Hersh, The Intraosseous Blood Supply of the Fifth Metatarsal:
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Implications for Proximal Fracture Healing. Foot Ankle, 1992. 13(3): p. 143-152. Strayer SM, R.S., Petrizzi MJ, Fractures of the proximal fifth metatarsal. American Family
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Physician 1999. 59(9): p. 2516-22.
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Sarimo, J., et al., Tension-Band Wiring for Fractures of the Fifth Metatarsal Located in the Junction of the Proximal Metaphysis and Diaphysis. The American Journal of Sports Medicine, 2006. 34(3): p. 476-480.
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Choi J, L.K., Lee Y, Lee J, Kim H, Surgical Results of Zones I and II Fifth Metatarsal Base Fractures
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Ochenjele, G., et al., Radiographic Study of the Fifth Metatarsal for Optimal Intramedullary
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Xie, L., et al., Locking compression plate distal ulna hook plate fixation versus intramedullary
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screw fixation for displaced avulsion fifth Metatarsal Base fractures: a comparative retrospective cohort study. BMC Musculoskeletal Disorders, 2017. 18(1): p. 405. 18.
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Table 1: Results after treatment of proximal fifth metatarsal fractures with hook plate osteosynthesis.
Table 1 (results)
patients
fractures
n = 21
n = 18
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Primarily surgically treated
(8/13)
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Gender
Total number of
(male/female) 38.7 (19-72)
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Age
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in years -
Time from
23 (3-224)
injury to
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surgery in days
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average (range)
average (range) Time to union
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in weeks -
7.7 (4.5-16)
average (range) Time to return of ADLs in weeks -
10.3 (4.5-37)
8.1 (4.5-21)
Average (range) Preoperative
30.4 (14-90)
31 (14-90)
95.2 (68-100)
97.8 (80-100)
AOFAS midfoot score -
Postoperative
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average (range)
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AOFAS midfoot score -
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average (range)