Functional outcomes after the treatment of hip fracture.

Osteoporotic hip fracture is a major public health issue. Estimation of the outcome and maximization of functional recovery after fracture is very important in the treatment of older patients. The purposes of this study were to clarify the functional outcomes after the treatment of hip fracture and to identify the factors that influence functional recovery. In the present study, 228 patients admitted to an acute-care hospital from January 2016 to June 2018 were evaluated. The patients were categorized into a trochanteric fracture group (n = 128) and a neck fracture group (n = 100). We retrospectively reviewed their ambulation ability 6 months after fracture using the Functional Ambulation Category (FAC) score. The other survey items were the presurgical duration, length of hospital stay, time until beginning to walk using parallel bars, complications affecting treatment, and mortality rate. The 6-month follow-up rate was 54.4% (n = 124). The results showed that the patients with trochanteric fracture were significantly older than those with neck fracture (86 vs. 82 years, respectively; p = 0.03). In total, 85.0% of patients with trochanteric fracture and 92.2% of patients with neck fracture were independent ambulators before injury (FAC score of 4 or 5). The FAC score 6 months after fracture was positively correlated with the FAC score before fracture and at discharge (all p<0.001) and negatively correlated with patient age (p<0.001) and presurgical duration for patients with neck fracture (p = 0.04). There was no statistically significant correlation with the length of hospital stay or the time until beginning to walk using parallel bars. In conclusion, patients with trochanteric fractures were older than those with neck fractures. In both fracture types, walking recovery 6 months after hip fracture was related to the FAC score before injury and at discharge from an acute-care hospital but not to the time until beginning to walk using parallel bars.

Introduction

Hip fracture is one of the most important health problems in patients of advanced age. Such fractures are classified as trochanteric fractures, neck fractures, and head fractures in the AO/OTA classification [1], and most osteoporosis-based hip fractures in patients of advanced age are trochanteric fractures (AO/OTA 31-A) and neck fractures (31-B). The incidence rate of hip fracture increases with aging, and evaluation of the ratios of trochanteric and neck fractures has revealed that more neck fractures occur in patients aged <75 years and that more trochanteric fractures occur in patients aged >75 years [2, 3]. Early surgical treatment and remobilization are recommended in the international clinical guidelines [4]; however, conservative treatment based on traction is sometimes necessary for some patients when surgical treatment is not possible because of fragility, severe complications, or delayed discovery of the fracture. In addition, no specific protocol has been established for early rehabilitation of hip fractures. In particular, walking is sometimes started before the patient has sufficient basic physical and muscle strength because of strong concern about starting walking early after surgery. We hypothesized that functional recovery after hip fracture may not be related to the start of walking during the acute rehabilitation period.

Most patients with hip fracture are very old, and few reports have described treatment outcomes, including conservative treatment. In addition, the difference in treatment outcomes between trochanteric and neck fractures is unclear. Therefore, an understanding of the relatively short-term outcomes and the factors that influence functional recovery is clinically important. This study was performed to report the functional outcomes of trochanteric versus neck fractures including the patients received conservative treatment and associated factors 6 months after hip fracture.

Methods

This was a retrospective cohort study. This research was approved by the Research Ethics Committee of University of Fukui (Permission number: 20190154). The data were corrected by medical records and analyzed anonymously. The patients included in the study were admitted to the University of Fukui Hospital, a 600-bed acute-care hospital located in the Hokuriku area of Japan, from January 2016 to June 2018. The study population comprised 228 patients (172 women and 56 men) categorized into the trochanteric fracture group (AO/OTA 31-A, n = 128) and the neck fracture group (31-B, n = 100). We evaluated the patients’ ambulation ability before injury, at discharge, and 6 months after injury from the medical records using the Functional Ambulation Category (FAC) score [5]. The FAC is 6-point scale ranging from 0 (nonfunctional ambulator) to 5 (independent ambulator) that evaluates the ambulation status by determining how much human support the patient requires when walking. Other items evaluated in this study were the presurgical duration, length of hospital stay, time until beginning to walk using parallel bars, and complications affecting treatment, and mortality rate.

Differences between groups were examined using the Mann–Whitney U test for median age, median presurgical days, and median hospital days; the chi-squared test for sex and complications; and Spearman’s correlation analysis for ambulation ability and correlating factors. A p value of <0.05 indicated a statistically significant difference between groups. All statistical analyses were performed using SPSS 10.0 (SPSS Inc., Chicago, IL, USA).

Results

The patients’ characteristics are shown in Table 1. All patients were divided into two groups; 128 had trochanteric fracture and 100 had neck fracture. The median age of all patients was 85 years (range, 32–99 years), and the patients with trochanteric fracture were significantly older than those with neck fracture (86 vs. 82 years, respectively; p = 0.03). Both types of fracture were more common in women (trochanteric fracture, 75.4%; neck fracture, 78.0%; p = 0.43). The main treatment for trochanteric fractures was osteosynthesis (83.6% of trochanteric fractures, n = 107), and the main treatment for neck fractures was bipolar hip arthroplasty (67.0% of neck fractures, n = 67). The numbers of patients treated conservatively were not significantly different between the two fracture types (14.8% of patients with trochanteric fracture and 15.0% of those with neck fracture, p = 0.97). The median presurgical duration and median hospital period were longer in patients with neck fracture than in those with trochanteric fracture (5 vs. 8 days and 16 vs. 21 days, respectively; both p<0.01). The main presurgical problems were severe diabetes requiring control (7.9%) and anticoagulation drug management (10.5%). The total mortality rate was 6.5% (10.0% [n = 6] of patients with trochanteric fracture and 3.1% [n = 2] of those with neck fracture, p = 0.12). There was no significant difference in the presurgical complications and the total mortality rate.

Table 1

Patients’ characteristics.

	Total	Trochanteric fracture	Neck fracture	p value
		(AO/OTA 31-A)	(AO/OTA 31-B)
Median age: years (range)	85 (32–99)	86 (32–99)	82 (43–96)	0.03
Gender: n (%)
Men	56 (24.6%)	34 (26.6%)	22 (22.0%)	0.43
Women	172 (75.4%)	94 (73.4%)	78 (78.0%)	0.43
Treatment: n (%)
Osteosynthesis	125 (54.8%)	107 (83.6%)	18 (18.0%)
Bipolar head arthroplasty	69 (30.3%)	2 (1.6%)	67 (67.0%)
Conservative	34 (14.9%)	19 (14.8%)	15 (15.0%)	0.97
Median presurgical days (range)	7 (0–38)	5 (0–31)	8 (0–38)	<0.001
Median hospital days (range)	18 (2–114)	16 (2–69)	21 (8–114)	<0.001
Complication: n (%)
Pneumonia	21 (9.2%)	11 (8.6%)	10 (10.0%)	0.72
DVT/PE	21 (9.2%)	14 (10.9%)	7 (7.0%)	0.31
Urinary infection	14 (6.1%)	9 (7.0%)	5 (5.0%)	0.55
Diabetes	18 (7.9%)	11 (8.6%)	7 (7.0%)	0.66
Necessity of presurgical drug management	24 (10.5%)	12 (9.4%)	12 (12.0%)	0.52
Surgical site infection	0 (0.0%)	0 (0.0%)	0 (0.0%)	1
Mortality: n (%)	8 (6.5% of 124)	6 (10.0% of 60)	2 (3.1% of 64)	0.12

Mann–Whitney U test for median age, median presurgical days, and median hospital days.

Chi-squared test for sex, complications, and mortality.

DVT: deep vein thrombosis.

PE: pulmonary embolism.

Ambulation ability was assessed using the FAC score as shown in Fig 1. The 6-month follow-up rate was 54.4% (n = 124), and the main reason for drop-out was transfer in both groups. In total, 85.0% (n = 51) of patients with trochanteric fracture and 92.2% (n = 59) of those with neck fracture were independent walkers (FAC score of 4 or 5) before injury. Six months after fracture, 56.7% (n = 34) of patients with trochanteric fracture and 70.3% (n = 45) of those with neck fracture maintained their walking ability (p = 0.21). A total of 53.3% (n = 32) of patients with trochanteric fracture and 42.2% (n = 27) of those with neck fracture showed a decrease in their FAC score by ≥1 point (p = 0.21). The patients with trochanteric fracture were more likely to be nonfunctional ambulators or bed-ridden (FAC score of 0) than those with neck fracture (16.7% [n = 10] vs. 3.1% [n = 2], respectively; p = 0.011).

Fig 1

FAC score before fracture and 6 months later.

The FAC score before fracture is shown on the left side of each graph, and the FAC score after 6 months is shown on the right side. The two scores are connected by a line, and the thickness of the line corresponds to the number of patients.

Fig 2 shows the factors correlated with the functional outcome. The FAC score at 6 months after fracture was positively correlated with the FAC score before fracture and at discharge (all p<0.001) and negatively correlated with patient age (p<0.001) and presurgical duration for patients with neck fracture (p = 0.04). There was no statistically significant correlation with the presurgical duration for patients with trochanteric fracture (p = 0.65), length of hospital stay (trochanteric fracture, p = 0.36; neck fracture, p = 0.15), or time until beginning to walk using parallel bars (trochanteric fracture, p = 0.30; neck fracture, p = 0.86).

Fig 2

Factors correlated with the functional outcome.

Discussion

Osteoporotic fracture is one of the most important medical/social problems leading to the need for long-term care and accounts for 12.5% of cases in which long-term care insurance is required [6]. In Japan, a nationwide survey by Orimo et al. [7] estimated that 37,600 men and 138,100 women sustained hip fractures in 2012 (total of 175,700 patients), and the annual number of patients is expected to increase in the future [8].

Osteoporotic hip fracture is divided into trochanteric fracture and neck fracture [1], and patients with trochanteric fracture are generally older than those with neck fracture [2, 3]. In the present study, patients with trochanteric fracture were significantly older than those with neck fracture; thus, our data support previous studies. Bone fragility of the trochanter region is considered to be a cause of trochanteric fractures in older people. Tanner et al. [9] reported that the types of hip fracture differ between men and women and that as women get older, they are more likely to sustain trochanteric fractures than are men. The authors considered that the intertrochanteric region absorbs the force passed along to the neck of the femur and that women are more likely to develop trochanteric fractures because they are more prone to osteoporosis than men [9].

International guidelines recommend early surgical treatment and rehabilitation; however, conservative treatment is chosen for some patients because of pre-existing disease such as heart failure, respiratory disorders, diabetes, renal failure, and other conditions. In this study, a relatively high percentage of patients were selected for conservative treatment because many of the patients had been referred from other hospitals, and some of them were judged as having high anesthetic risk. The patients who received conservative treatment were transferred to another hospital and underwent protective care and rehabilitation at that institution. In the present study, patients aged >85 years accounted for about 50% of the total patients, and 45% of them were >90 years old; this is considered to be the reason for the relatively high 6-month mortality rate (6.5%) and proportion of nonfunctional ambulators or bed-ridden patients (9.7%). However, some selection bias may have occurred because we excluded patients who did not present to our hospital. The follow-up rate were relatively low because the many patients returned to the home town far from our hospital, and were supported only by local facility care services. In previous studies that evaluated treatment outcomes including those for patients who received conservative treatment, the annual mortality rate ranged from 10% to 40% [10-12]. Factors reportedly associated with higher mortality included aging, male sex, cognitive dysfunction, cardiovascular disease, respiratory disease, diabetes mellitus, and malignant tumors [10-15]. The Charlson comorbidity index [12] and the American Society of Anesthesiologists Physical Status Classification System [13] are were also both reportedly associated with mortality.

The functional prognosis of hip fractures differs between surgical and conservative treatment, and few reports have described treatment outcomes, including conservative treatment. In the present study, 56.7% of patients with trochanteric fracture and 70.3% of those with neck fracture maintained their walking ability at 6 months after fracture, and patients with trochanteric fracture were more likely to be nonfunctional ambulators or bed-ridden than those with neck fracture. Patient age may have been a confounding factor. Factors associated with the functional prognosis were patient age, the FAC score before fracture and at discharge, and presurgical days in patients with neck fracture. We found no correlation between presurgical days and hospital days. Previous reports have shown a strong association between functional recovery and age, preoperative physical function, and cognitive function [16]. The cutoff value for age is not clear, but older age is associated with poorer recovery of walking ability. The motor Functional Independence Measure score [17] and the New Mobility Score [18] are examples of methods used to evaluate physical function. The FAC is a simple evaluation method, and the preoperative FAC score is related to the 6-month postoperative score. This scoring method is considered suitable for evaluating the walking ability of patients with proximal femoral fractures. Although we did not statistically analyze cognitive function in this study, cognitive function is evaluated in almost all patients, and occupational therapy is performed to maintain cognitive function and improve activities of daily living. About the timing of surgery, the National Institute for Health and Care Excellence recommends early surgery within 48 hours [4]; this strategy is associated with advantages such as reduced complications and improved functional recovery. Although early surgery is reported to be positively associated with the life prognosis [14], it is generally possible that a patient with no or few complications has undergone early surgery, and the effect of bias may be considered. In a Japanese study, 2010–2014 data showed that only 22.5% of patients underwent surgery within 2 days of hospitalization, and the risk of pneumonia and pressure ulcers was significantly reduced in the early surgery group [19].

Preoperative rehabilitation and early mobility are recommended, and there are numerous reports of valid rehabilitation protocols [20]. However, the 2011 Cochrane Review concludes that there is insufficient evidence from randomized trials to establish the best strategies for enhancing mobility after hip fracture surgery [21]. In the present study, the duration of time until beginning to walk using parallel bars was not related to the walking ability after surgical treatment, and we found that early compelled walking did not improve functional ability. Walking is unstable, slow, and poorly coordinated in most people of advanced age; this is caused by not only musculoskeletal weakness but also cardiovascular dysfunction and neurological problems or cognitive dysfunction [22]. Rehabilitation programs to regain ambulatory ability after hip fracture should include basic range-of-motion exercises, muscular strengthening, aerobic exercise, and occupational therapy. Notably, however, the results of recent randomized controlled trials have indicated the beneficial effects of multidisciplinary rehabilitation and post-discharge exercise programs [23-26]. Based on these reports, we consider that not only acute treatment but also home exercise after discharge and a multidisciplinary approach are important for functional recovery and improvements in activities of daily living after hip fracture. In recent years in Japan, community activities have been vigorously conducted for the purpose of long-term care prevention. Therefore, proactive introduction of such services to patients with hip fracture can be expected to maintain and improve motor function.

Conclusion

In conclusion, we found patients with trochanteric fractures were older than those with neck fractures, which supports the findings of previous studies. At least in our sample, walking recovery 6 months after hip fracture was related to the FAC score before injury and at discharge from an acute-care hospital but not to the time until beginning to walk using parallel bars in both fracture types. Walking ability at the time of discharge from an acute-care hospital can be a predictor of the outcome, but inappropriate early initiation of walking is not recommended.

Anonymous patient data.

(PDF)

Click here for additional data file.

24 Mar 2020

PONE-D-20-02630

Functional outcomes after the treatment of hip fracture

PLOS ONE

Dear Dr. Takahashi,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

The authors are required to identify their primary objective of the study and to other secondary objectives, then they can link their methodology and results relative to the their objectives.

We would appreciate receiving your revised manuscript by May 08 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Osama Farouk

Academic Editor

PLOS ONE

Additional Editor Comments (if provided):

The article needs extensive revision of the points raised by the reviewers. Please, respond to the reviewers' comments one by one.

Journal Requirements:

When submitting your revision, we need you to address these additional requirements:

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at http://www.plosone.org/attachments/PLOSOne_formatting_sample_main_body.pdf and http://www.plosone.org/attachments/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. Please ensure you have thoroughly discussed any potential limitations of this study within the Discussion section, for example the potential impact of confounding factors.

3. Please include your tables as part of your main manuscript and remove the individual files. Please note that supplementary tables (should remain/ be uploaded) as separate "supporting information" files

4. PLOS requires an ORCID iD for the corresponding author in Editorial Manager on papers submitted after December 6th, 2016. Please ensure that you have an ORCID iD and that it is validated in Editorial Manager. To do this, go to ‘Update my Information’ (in the upper left-hand corner of the main menu), and click on the Fetch/Validate link next to the ORCID field. This will take you to the ORCID site and allow you to create a new iD or authenticate a pre-existing iD in Editorial Manager. Please see the following video for instructions on linking an ORCID iD to your Editorial Manager account: https://www.youtube.com/watch?v=_xcclfuvtxQ

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: No

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: No

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: No

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Introduction:

Sentences too long.

Methods:

What were the medical conditions prior to trauma? Was there a significant difference between trochanteric and neck fractures regarding pre-existing disease/comorbidities?

Please clarify why the pre-surgical duration was that long in both groups. In Germany, we are obligated to perform surgery within 36 hours in hip fractures.

Did your patients stay in an acute trauma facility for over 18 days?

Please explain the high rates of conservative treatment. Even though only 14 patients had a FAC of three or less, 34 patients were treated conservatively. I can hardly remember a geriatric/older patient in my clinic who was not surgically treated for a hip fracture.

How were the “nonfunfuctional or bed-ridden patients” treated?

Did your patients receive rehabilitation programs after being discharged? Did these programs have an effect?

Did the pre-operative ASA score have a predictive value of the post-surgical result?

Discussion:

Line 169pp: “We found that not only acute care and rehabilitation but also home exercise after

170 discharge and adequate social support are also important for functional recovery and improvements in activities of daily living after hip fracture.“

I cannot find any correlation in your text.

What is the reason for your high rates of mortality and non-walkers? Please discuss.

Reviewer #2: General comments:

The study idea about Functional outcomes after the treatment of hip fracture

is a clinically important area of research in hip fracture patients.

But unfortunately, the manuscript is not written in a way that made integration between the manuscript sections. There is discrepancy between the aim of the study and the methodology. Some linguistic revision is required.

However, I have provided some remarks below.

Abstract:

The abstract all over its section should be corrected accordingly after rewriting of the manuscript.

Introduction

- Replace cervical fracture with neck fracture to standardize.

- Classification of fractures indicate that it has an important significance in aim, methods and results.

- Between lines 57 to 62: is not related to the aim of the study.

- The introduction should concentrate on the factors affecting the functional outcomes and mortality after treatment of hip fracture, which is the point of the study.

- The aim of the study is different from the way of the methodology and results, The aim could be “ to study the difference in functional outcomes after treatment of neck and trochanteric types of hip fracture”

Methods:

- There is no mentioning to the study design.

- There was a clear statement in the methodology section in the abstract about inclusion of the sample as two categories” trochanteric and neck fractures”, but here it’s not clear. As it’s clear, this is the start point of data collection.

- The mean age is better to be mentioned in the results section.

- Mortality was not mentioned as an important finding in the follow up. Was mentioned in the abstract.

- Which data were exactly retrieved from the patients’ records and which were from the actual follow up? Or all data were retrieved from the records? Lines 76 and 77

- Were the data tested for normal distribution or not?

- In data analysis, what about tests of significance for non parametric data and presentation of data as median in spite of mean?

- Why multiple analysis was not done ?

Results:

- In general, No titles were wrote for tables and figures

- Put symbols inside tables and refer to the test used as a footnote under the tables.

- The way of presentation in results started with the categorization of the total sample to two fracture groups till the end of results.

- Table (1):

• Present age and duration as mean + SD or as median according to the normal parametric distribution of data.

• Present the age as range, there is age of 32years old, please analyze age in details as it’s an important factor

• What is “PE”? write in details.

• Please, mention all items that were mentioned in this table, write them in the methods section.

• Where is the mortality in both groups? Please include it. In addition to the mean duration of postoperative mortality duration.

• mention the drop out on both groups

- Figure (2):

• In page 12, lines 112 to 117: mention the drop out at the end of follow up.

•

Discussion:

- Page 13, Lines 121 to 136: Introduction not related to the findings of the study, just one short paragraph about the importance of the study.

- Present the findings of this study and then compare with the others’ results, explain??

- Here, other studies’ results were presented firstly.

- 1Page 14, lines 47 – 159: not related to the studied aspects.

- Page 14, sentence started in line 169 “we found that…” This is not studied in this study??

Conclusion:

- The mortality is not a primary outcome to be mentioned first here.

- Conclusion not based on the categorization of the study sample according to the type of fracture, and the difference in functional outcomes and mortality

- Include a recommendation in this section.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

8 May 2020

Point-by-Point Responses to Comments of Reviewer #1

We would like to thank Reviewer #1 for evaluating our manuscript. Our responses to the reviewer’s comments are provided below. We apologize for the statistical errors in the first manuscript. The data did not follow a normal distribution; therefore, we have corrected the median patient age, preoperative duration, and hospitalization duration and revised the statistical methods.

1. What were the medical conditions prior to trauma? Was there a significant difference between trochanteric and neck fractures regarding pre-existing disease/comorbidities?

In lines 92 to 97 of the revised manuscript, we have explained that the patients had multiple complications but that there was no significant difference between the two fracture groups.

2. Please clarify why the pre-surgical duration was that long in both groups. In Germany, we are obligated to perform surgery within 36 hours in hip fractures.

As described in the text, there were many serious cases in our hospital in which the patients had been transferred/referred from other hospitals. In addition, some patients required preoperative anticoagulation therapy, and evaluation and treatment required a period of several days or more before surgery.

3. Did your patients stay in an acute trauma facility for over 18 days?

We apologize for the statistical error. As shown in Table 1, the median length of stay for all patients was 18 days. Almost all patients were transferred to another hospital for the purpose of continuing medical care and rehabilitation after treatment. Acute rehabilitation was performed in our hospital.

4. Please explain the high rates of conservative treatment. Even though only 14 patients had a FAC of three or less, 34 patients were treated conservatively. I can hardly remember a geriatric/older patient in my clinic who was not surgically treated for a hip fracture.

As mentioned in our response to Comment 2, many high-risk patients were transferred from other hospitals; this resulted in a high number of patients who needed conservative treatment at our hospital.

5. How were the “nonfunfuctional or bed-ridden patients” treated?

Did your patients receive rehabilitation programs after being discharged? Did these programs have an effect?

As mentioned in our response to Comment 3, almost all patients were transferred to another hospital for the purpose of continuing medical care and rehabilitation after treatment. Acute rehabilitation was performed in our hospital. Unfortunately, data could not be collected for some patients who were transferred to another hospital, which resulted in a low follow-up rate of 54.4%. The local newspapers and other sources provided fairly accurate information about the patients who died after discharge.

6. Did the pre-operative ASA score have a predictive value of the post-surgical result?

Some patients were judged to have a high surgical risk without consulting with the anesthesia department regarding the patient’s medical condition, and the ASA score was not present in the medical record. Such patients received conservative treatment. Therefore, we did not compare ASA scores with functional outcomes in this study.

7. Line 169pp: “We found that not only acute care and rehabilitation but also home exercise after discharge and adequate social support are also important for functional recovery and improvements in activities of daily living after hip fracture.“

I cannot find any correlation in your text.

We apologize for our unclear description. In lines 193 to 195, we have revised the text as follows: “Based on these previous reports, we consider that not only acute care and rehabilitation but also home exercise after discharge and adequate social support are important for functional recovery and improvements in activities of daily living after hip fracture.” As you pointed out, this content is not directly related to our results; however, we believe that continuation of exercise after discharge and enhancement of social security are important for hip fracture management.

8. What is the reason for your high rates of mortality and non-walkers? Please discuss.

As mentioned above, many high-risk patients were treated in our hospital; as a result, 14.9% of patients received conservative treatment. Most patients who received conservative treatment were unable to walk, including those who did not die. However, there was no significant difference in mortality between the two groups. We believe that the reason for the higher number of nonfunctional ambulators among patients with trochanteric fractures is that age may have been a confounding factor. We have mentioned this in lines 164 to 166.

Point-by-Point Responses to Comments of Reviewer #2

We thank Reviewer #2 for evaluating our manuscript. We have revised the content according to the advice provided. Our responses to the reviewer’s comments are provided below.

Introduction:

1. Replace cervical fracture with neck fracture to standardize.

We have revised the text accordingly.

2. Classification of fractures indicate that it has an important significance in aim, methods and results.

As you mentioned, classification of the two fracture types is important in this study. We have revised the Introduction accordingly.

3. Between lines 57 to 62: is not related to the aim of the study.

We have removed this section of text.

4. The introduction should concentrate on the factors affecting the functional outcomes and mortality after treatment of hip fracture, which is the point of the study.

In this study, we focused on clarifying the functional outcome, including patients who received conservative treatment. Therefore, we have mentioned in the Introduction that there are few similar studies (line 56-58). Factors affecting the functional prognosis are discussed in the Discussion section (line 166-169).

5. The aim of the study is different from the way of the methodology and results, The aim could be “ to study the difference in functional outcomes after treatment of neck and trochanteric types of hip fracture”

We have revised the text accordingly. The end of the Introduction now reads, “Most patients with hip fracture are very old, and few reports have described treatment outcomes, including conservative treatment. In addition, the difference in treatment outcomes between trochanteric and neck fractures is unclear. Therefore, an understanding of the relatively short-term outcomes and the factors that influence functional recovery is clinically important. This study was performed to report the functional outcomes of trochanteric versus neck fractures and associated factors 6 months after hip fracture.”

Methods:

6. There is no mentioning to the study design.

We apologize for not mentioning the study design. At the beginning of the Methods section, we have added the following text: “This study was conducted by retrospective medical record evaluation.”

7. There was a clear statement in the methodology section in the abstract about inclusion of the sample as two categories” trochanteric and neck fractures”, but here it’s not clear. As it’s clear, this is the start point of data collection.

In accordance with your comment, we have added the following text to the revised manuscript: “The study population comprised 228 patients (172 women and 56 men) categorized into the trochanteric fracture group (AO/OTA 31-A, n=128) and the neck fracture group (31-B, n=100).”

8. The mean age is better to be mentioned in the results section.

We have accordingly mentioned patient age in the Results section.

9. Mortality was not mentioned as an important finding in the follow up. Was mentioned in the abstract.

We have revised the abstract in accordance with your comment.

10. Which data were exactly retrieved from the patients’ records and which were from the actual follow up? Or all data were retrieved from the records?

At the beginning of the Methods section, we have mentioned that all data were collected from the medical records.

11. Were the data tested for normal distribution or not?

We apologize for our statistical error in the first manuscript. The data did not follow a normal distribution. Therefore, we have corrected the median patient age, preoperative duration, and hospitalization duration and changed the statistical method.

12. In data analysis, what about tests of significance for non parametric data and presentation of data as median in spite of mean?

We changed the statistical method in accordance with your advice. Differences between groups were examined using the Mann–Whitney U test for median age, median presurgical days, and median hospital days.

13. Why multiple analysis was not done ?

Although not described in the text, no statistically significant difference was found in the factors associated with the functional outcome by multivariate analysis.

Results:

14. In general, No titles were wrote for tables and figures

We have added titles to the tables and figures.

15. Put symbols inside tables and refer to the test used as a footnote under the tables.

We have revised the tables according to your instructions.

16. The way of presentation in results started with the categorization of the total sample to two fracture groups till the end of results.

We have accordingly mentioned the categorization of the patients at the beginning of the Results section.

Table (1):

17. Present age and duration as mean + SD or as median according to the normal parametric distribution of data.

The data are now presented as median values.

18. Present the age as range, there is age of 32 years old, please analyze age in details as it’s an important factor

We have accordingly presented the patients’ age as a range.

19. What is “PE”? write in details.

“PE” stands for pulmonary embolism. We apologize for omitting this definition; it has been added to Table 1.

20. Please, mention all items that were mentioned in this table, write them in the methods section.

We have mentioned all items from the table in the Methods section (line 68-74).

21. Where is the mortality in both groups? Please include it. In addition to the mean duration of postoperative mortality duration.

We have accordingly added the mortality rates for each group to Table 1. Because of the method of data acquisition, we were unable to obtain the accurate average mortality period.

22. mention the drop out on both groups

We have stated that the reason for drop-out was transfer in both groups.

Figure (2):

23. In page 12, lines 112 to 117: mention the drop out at the end of follow up.

At the beginning of the Methods section, we have stated that all data in this study were obtained from the patients’ medical records (line 64). Therefore, we have omitted all data that were not obtained from the medical records.

Discussion:

24. Page 13, Lines 121 to 136: Introduction not related to the findings of the study, just one short paragraph about the importance of the study.

We think epidemiological description in Japan is important; the unrelated text has been deleted.

25. Present the findings of this study and then compare with the others’ results, explain??

We have revised the Discussion section to compare our results with past reports.

26. Here, other studies’ results were presented firstly.

We prefer to mention the results of other studies first, if possible. We have described our results and others in the same paragraph.

27. Page 14, lines 47 – 159: not related to the studied aspects.

In the final paragraph, we discuss rehabilitation and integrated management. We have listed the types of rehabilitation that are reportedly useful for hip fractures, and we consider that both acute rehabilitation and long-term support are necessary.

28. Page 14, sentence started in line 169 “we found that…” This is not studied in this study??

We apologize for our unclear description. In lines 193 to 195, we have revised the text as follows: “Based on these previous reports, we consider that not only acute care and rehabilitation but also home exercise after discharge and adequate social support are important for functional recovery and improvements in activities of daily living after hip fracture.” As you pointed out, this content is not directly related to our results; however, we believe that continuation of exercise after discharge and enhancement of social security are important for hip fracture management.

Conclusion:

29. The mortality is not a primary outcome to be mentioned first here.

As you pointed out, mortality is not the main outcome; therefore, we did not list it here.

30. Conclusion not based on the categorization of the study sample according to the type of fracture, and the difference in functional outcomes and mortality

We have revised the Conclusion section as follows: “In conclusion, we found patients with trochanteric fractures were older than those with neck fractures, which supports the findings of previous studies. At least in our sample, walking recovery 6 months after hip fracture was related to the FAC score before injury and at discharge from an acute-care hospital but not to the time until beginning to walk using parallel bars in both fracture types.”

31. Include a recommendation in this section.

We have added the following sentence to the end of the Conclusion section: “Walking ability at the time of discharge from an acute-care hospital can be a predictor of the outcome, but inappropriate early initiation of walking is not recommended.”

Submitted filename: Point-by-Point Responses.docx

Click here for additional data file.

26 May 2020

PONE-D-20-02630R1

Functional outcomes after the treatment of hip fracture

PLOS ONE

Dear Dr. Takahashi,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Jul 10 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

We look forward to receiving your revised manuscript.

Kind regards,

Osama Farouk

Academic Editor

PLOS ONE

Additional Editor Comments (if provided):

The authors are required to respond to all reviewer's comments. The discussion needs extensive revision.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: (No Response)

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: (No Response)

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: (No Response)

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: (No Response)

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: (No Response)

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Dear authors,

thank you for revising your paper.

To my mind your paper is now technical Sound and all data to Support your conclusions is provided. Statistical analyses have improved.

Reviewer #2: Overall, the changes that were made in response to the review are accepted except:

1- Point 6 in methodology, “ retrospective medical record evaluation” this is not a study design, the study design of this research is “ retrospective cohort study”.

2- Discussion:

Presentaion of the discussion should be done with the study presentation first then to compare with other studies, not the reverse.

There is no discussion for morbidity or mortality factors

The age and sex factors are discussed well.

No discussion with the hospital stay,……

No discussion with factors related to the walking ability.

In pages 17& 18, lines 240 to 262: are not related to presented data. In this study there are no evaluation of the rehabilitation done for patients in both groups. Could be written in two to three lines only.

Write recommendation related to results.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

30 Jun 2020

Point-by-Point Responses to Comments of Reviewer #1

We would like to thank Reviewer #1 for evaluating our manuscript. We added discussions about mortality, length of presurgical duration, and factors associating with walking ability, resulting in changes from Discission lines 150 to 161, 178 to 185, and lines 167 to 178. Also, the description of rehabilitation was changed by citing some recent randomized controlled trials (lines 186 to 189 and 196 to 201).

Point-by-Point Responses to Comments of Reviewer #2

We thank Reviewer #2 for evaluating our manuscript. We have revised the content according to the advice provided. Our responses to the reviewer’s comments are provided below.

1. Point 6 in methodology, “ retrospective medical record evaluation” this is not a study design, the study design of this research is “ retrospective cohort study”.

We have revised the text accordingly (line 63 to 65).

Discussion:

2. Presentaion of the discussion should be done with the study presentation first then to compare with other studies, not the reverse.

We have revised the text accordingly.

3. There is no discussion for morbidity or mortality factors

We added the discussion about mortality rate in lines 150 to 161.

4. No discussion with the hospital stay,……

We added the discussion about presurgical duration in lines 178 to 185. In this study, there was no correlation wit hospital stay and functional recovery, so we are not discussing length of hospital stay.

5. No discussion with factors related to the walking ability.

We added the discussion about factors related to the walking ability in lines 167 to 178.

6.In pages 17< 18, lines 240 to 262: are not related to presented data. In this study there are no evaluation of the rehabilitation done for patients in both groups. Could be written in two to three lines only. Write recommendation related to results.

We omitted the item on rehabilitation content and revised it by citing some recent randomized controlled trials. (lines 186 to 189 and 196 to 201).

Submitted filename: Point-by-Point Responses2.docx

Click here for additional data file.

13 Jul 2020

Functional outcomes after the treatment of hip fracture

PONE-D-20-02630R2

Dear Dr. Takahashi,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Osama Farouk

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

All reviewers' comments were addressed.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: (No Response)

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: No

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: Dear authors

From my point of view, this manuscript is accepted to be published after all corrections

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: Yes: Dalia G Mahran

17 Jul 2020

PONE-D-20-02630R2

Functional outcomes after the treatment of hip fracture

Dear Dr. Takahashi:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Osama Farouk

Academic Editor

PLOS ONE