Functional ability before and after rehabilitation in elderly patients with shortening and/or rotational deformity of the lower limb after hip fracture

Shortening and rotational deformity of the lower limb (SRD) is a major complication of hip fracture surgery. It causes not only hip joint dysfunction but also functional impairments due to abnormal gait parameters, decreased gait velocity, and poor balance. Despite a number of previous studies, the effect of SRD on the postsurgical recovery of these patients is still not clear.


INTRODUCTION
Hip fracture is one of the most frequent traumatic injuries in elderly people and its incidence is rising due to increasing life expectancy, reduced bone mineralization, and the increased risk of falls in the growing elderly population.Hip fracture is considered one of the most dangerous fractures for elderly people, resulting in impaired function and increased morbidity and mortality. 1n the year after fracture, mortality ranges from 12% to 17% and the risk of death is twofold compared to nonfracture controls. 2Of the patients who lived independently before a hip fracture, only one half walk without assistance again, and 20% have to move to a long-term care facility and never return home. 3he intervention for hip fracture is surgical and consists of internal fixation (osteosynthesis) or hip replacement (hemi or total).The choice is based on the type and site of the fracture, the patient's age, comorbidities, the presence of osteoporosis, and the surgeon's own preference. 4owever, following surgery for a hip fracture, there is a high risk for postsurgical complications related to the intervention itself or the in-hospital stay. 5Complications directly related to the surgery include wound infection, dislocation, failure of fixation, and peri-prosthetic fracture, and other clinical complications include pneumonia, urinary tract infection, and venous thromboembolism. 6Postoperative complications hinder the rehabilitation, increase the length of stay in hospital, and result in excess morbidity and mortality in an already high-risk group. 6n important complication of surgery in hip fracture is the shortening and rotational deformity of the lower limb 4 (SRD), which occurs when a broken bone heals in an abnormal position (malunion) 7,8 or the prosthesis is malpositioned. 9Shortening and/or rotational deformity can appear both in internal fixation and hemiarthroplasty [10][11][12] but are more common after internal fixation, occurring in over 30% of patients. 10,11hortening of the lower limb leads to problems that can include discomfort and intense pain in the affected hip when bearing weight but also weakness in hip abduction muscles and loss of motion, especially in the hip joint. 10,13][16] Rotational deformity of the lower limb can hinder more demanding activities like running, sports, and climbing stairs after femoral shaft fractures, 17 but its influence on functional activities after hip fractures has not yet been clarified.
To date, despite diverse studies performed, we still know little about the balance and functional deficits, both before and after rehabilitation, of patients with SRD after hip fractures.Our study aims to address this knowledge gap, as clarification of these issues may help physicians in planning an optimal rehabilitation program and a safe home discharge.

Participants
We conducted this prospective observational cohort study at the Istituti Clinici Scientifici Maugeri.The study consisted of a secondary analysis of data from our database evaluating the effect of hip diseases on balance in patients admitted to our institute for rehabilitation between January 2015 and December 2017.The database included both patients with stable hip fracture and, hence, directly transferred from orthopedic departments to our rehabilitation department, and patients who were first discharged home or to a nursing home after hip surgery because they could not bear weight on the operated limb.The latter patients performed mobilization activities at home/nursing home before admission to our rehabilitation department.
From this database, we excluded patients aged ≤65 years or referred from other departments with concomitant acute events or patients who died or were transferred back to acute care during the rehabilitation.We also excluded patients who did not give informed consent or could not walk or perform basic activities without help before the fracture or had a pathological fracture.
All patients came from orthopedic departments of five hospitals in our health district, where the choice of surgical treatment was based exclusively on the experience and personal preference of the surgeon.
The Local Review Board (Technical Scientific Committee of our institute) approved the study protocol; all patients gave their written informed consent to participate at the time of admission.The study was conducted in accordance with the principles of the Declaration of Helsinki.

Mode of assessment
9][20][21] The evaluation before and after rehabilitation was usually performed by the same physician.Demographic characteristics and comprehensive clinical data were collected.These included time from surgery to admission for rehabilitation (days), length of stay in the rehabilitation unit (LOS), home or nursing home (days), use of painkillers, and presence of SRD.
We defined SRD as the presence of femoral shortening by at least 5 mm and/or a rotational malalignment of >15 .
These cutoffs were chosen based on previous studies 10,11,22,23 that considered lower limb shortening <5 mm as clinically insignificant, 10,11 rotational malalignment <10 as normal, and a rotation of 10-15 as a gray area (in which the para-physiological malrotation was acceptable). 17,22

Assessments
At admission, we performed the following scales or tests: • The Cumulative Illness Rating Scale (CIRS), to evaluate comorbidities. 20In this study, we considered the average severity of all comorbidities (severity index).• A tape to measure the shortened lower limb.We measured the distance between the anterior superior iliac spine and the medial malleolus of the ankle with the patient in supine position. 23 A manual goniometer to assess rotational malalignment of the operated limb.We assessed degrees of foot rotation with the patient in supine position and the knee extended 24 and classified patients as being with (>15 ) or without (<15 ) rotational malalignment.
At admission and discharge, we administered the following scales: • The Berg Balance Scale (BBS) to measure balance among patients with hip fracture by assessing the performance of functional tasks. 21The BBS consists of 14 items that require patients to maintain positions of varying difficulty and perform specific tasks.Each item is scored on a 5-point ordinal scale from 0 (unable to perform) to 4 (normal performance); hence, the aggregate score of BBS ranged from 0 to 56. • The Functional Independence Measure (FIM) was used to assess patients' degree of independence and need for assistance in performing basic activities of daily living (ADLs). 18It is an 18-item ordinal scale with each item rated from 1 (total dependence) to 7 (total independence).The FIM can be subdivided into a 13-item motor subscale (motor-FIM) and a 5-item cognitive subscale (cognitive-FIM).Motor-FIM scores range from 13 to 91 and cognitive-FIM scores from 5 to 35, with a maximum total score of 126.• An 11-point Visual Numeric Scale (VNS) from 0 (no pain) to 10 (intolerable pain), was used to measure hip pain intensity. 25 The Muscle Strength Grading Scale (Oxford Scale), was used to assess hip muscle strength. 26The score ranges from 0 (no movement) to 5 (muscle contracts against full resistance).In this study, we considered the sum of flexor and abductor hip muscle strength and quadriceps strength.• A manual goniometer was used to measure the range of motion (ROM) of the hip joint.The sum of ROM in flexion (0-130 ) and abduction (0-45 ) was considered. 24

Outcome measures
The motor-FIM and BBS scores before and after rehabilitation, efficiency and effectiveness in motor-FIM and BBS, and LOS were the outcome measures.Efficiency represents the average increase per day obtained by therapy (rehabilitation) 27 and has been used in previous studies concerning hip fracture recovery. 28,29It was calculated by dividing the gain in outcome measures during rehabilitation by the number of days in the hospital. 27ffectiveness is the proportion of potential improvement achieved during rehabilitation, calculated as (final scoreÀinitial score)/(maximum scoreÀinitial score) Â 100.Therefore, if a patient achieves the top score after rehabilitation, effectiveness is 100%. 27

Rehabilitation program
The rehabilitation program commenced the day after admission to our institute.It consisted of an average of 330 min/week of conventional motor rehabilitation (6 days/week) for the entire duration of the hospital stay and 150 min/week of occupational therapy only in the last 2 weeks of the hospital stay.In addition, patients received nursing rehabilitation in ward activities, electrostimulation of quadriceps, and, if pain was present, ultrasound, laser, or transcutaneous electrical nerve stimulation at the physician's discretion.Each patient's nursing needs, specific rehabilitation goals, and progress/outcomes were discussed at admission and bimonthly by a rehabilitation team composed of physicians, nurses, physiotherapists, and an occupational therapist.Rehabilitation was conducted in an in-patient setting by physiotherapists and an occupational therapist (3-year professional qualification) with more than 5 years of experience in the rehabilitation of orthopedic diseases.
The motor rehabilitation program was conventional and based on hip ROM, muscle strengthening (isotonic and isometric exercises), conditioning exercises, bedto-chair mobility, wheelchair skills, pregait activities (sit to stand, standing balance), and gait activities (parallel bars, walker, crutches), bathroom skills, and ADL training.Participants were discharged when, in the opinion of the rehabilitation team, they did not improve further through the rehabilitation training.

Statistical analysis
Data were analyzed statistically using the software application Statistica version 6 (StatSoft, Tulsa, OK, USA; 2001).Statistical analysis was performed with descriptive analyses (number, median, 25-75th percentile, percentage), chi-square tests (Fisher exact or Pearson as appropriate), and the Wilcoxon and Mann-Whitney tests to examine differences within and between groups, respectively.p values <.05 were considered statistically significant.

RESULTS
In the period considered, our database included 119 people with hip fractures.Of these, 102 patients (59 with internal fixation and 43 with hemiarthroplasty) were eligible for the outcome analysis: they consisted of 40 with SRD of the lower limb and 62 without.All patients, before the fracture, were living at home.Table 1 reports patients' clinical and demographic characteristics according to the presence/absence of lower limb SRD.
Table 2 reports the results of the outcome measures and clinical variables of patients according to the presence/absence of SRD.Before rehabilitation, patients with SRD had lower (ie, worse) hip ROM (p = .001),hip muscle strength (p < .001),motor-FIM (p = .002),and BBS score (p = .001)compared to those without SRD.At the end of rehabilitation, patients with SRD continued to have lower hip ROM (p = .001),hip muscle strength (p < .001),motor-FIM (p = .014),and BBS (p = .003)compared to those without SRD.As Table 2 shows, patients with SRD at the end of rehabilitation also had lower effectiveness in motor-FIM (p = .039)and BBS (p = .034)than those without SRD.
Figure 1 shows the improvements in motor-FIM and BBS score and ROM (Figure 1(A)), and muscle strength and pain (Figure 1(B)), according to the absence/presence of SRD at the end of rehabilitation.Patients both with and without SRD experienced improvements in BBS, motor-FIM, muscle strength, ROM, and pain scores compared to baseline (Table 2, p < .001,for all) and the changes in these variables did not differ between groups (p = ns, for all).
Tables 3 and 4 report the results of the outcome measures and clinical variables for patients with versus without SRD who underwent hemiarthroplasty and internal fixation, respectively.
Patients with hemiarthroplasty and SRD demonstrated lower motor FIM scores before rehabilitation and lower BBS scores before and after rehabilitation than those without SRD (Table 3).Patients with internal fixation and SRD had lower BBS, motor FIM, ROM, and hip strength scores before and after rehabilitation, lower efficiency and effectiveness in motor-FIM, higher pain score, and a longer LOS in rehabilitation compared to patients without SRD (Table 4).

DISCUSSION
This study aimed to evaluate functional abilities and balance before and after rehabilitation for people with hip fractures and to assess the effect of SRD of the lower limb on their rehabilitation.The study showed that before rehabilitation patients with SRD had lower motor-FIM and balance than those without SRD.After rehabilitation, balance and ADLs significantly improved in patients both with and without SRD and the change was similar between groups.Therefore, at the end of the rehabilitation program, individuals with SRD continued to have lower balance and greater ADL deficits than those without SRD.These findings indicate that, in people with hip fractures, SRD is associated with lower balance and functional abilities both before and after rehabilitation.We did not find any studies evaluating balance and ADLs in patients with hip fracture and SRD before/after rehabilitation and so we could not compare our findings with those of other authors.However, one study evaluated the health status and quality of life of hip fracture patients with femoral shortening and showed that people with moderate-severe shortening used walking aids in 43%-83% of cases and had lower health status and quality of life compared to people with no or mild shortening 20 months after surgery. 11ur study thus clarifies the role of SRD, suggesting that it not only affects health status and quality of life in people undergoing surgery for hip fracture, as demonstrated by Zlowodzki, 11 but also has a negative effect on balance and functional abilities.
In our study, patients with and without SRD did not differ in terms of age, time from surgery to admission for rehabilitation, use of painkillers, destination after surgery, LOS, cognitive functions and comorbidity level, or the rehabilitation program, suggesting that our findings, before and after rehabilitation, were mainly due to SRD.Note: Data are expressed as median (25-75th percentile); Comparison between groups was performed by the Mann-Whitney test.A p < .05 was considered statistically significant.Abbreviations: FIM, Functional Independence Measure; LOS, length of hospital stay; ROM, range of motion; SRD, shortening and rotational deformity of the lower limb; VNS, Visual Numeric Scale.
F I G U R E 1 Changes in motor-FIM, BBS score, ROM (A) and muscle strength and pain (B) pre-post rehabilitation in patients without SRD (SRD-) and with SRD (SRD+).Mann-Whitney test was used to examine differences between groups.p values are reported above the graph.1] Moreover, it leads to hip joint dysfunction with changes in the moment arm of the abductor muscles, decreased range of motion, and more intense pain. 10,131][32] At the end of rehabilitation, participants with SRD also showed less effectiveness in balance and functional abilities.Effectiveness represents the percentage of improvement achieved with rehabilitation and can be considered an indicator of the efficacy and appropriateness of a rehabilitation program. 27These findings indicate that SRD is a factor that adversely affects the rehabilitation program concerning balance and ADLs.
The study showed that patients with SRD also had lower hip ROM and muscle strength before and after rehabilitation with respect to those without SRD.This indicates that SRD of the lower limb is associated with more severe hip joint dysfunction, confirming the findings of previous studies. 10,13fter surgery, most of the patients were directly transferred to rehabilitation, whereas a minority were temporarily discharged home or to a nursing home because they did not have a stable fracture after surgery.However, there was no difference between patients with versus without SRD in terms of time from surgery to admission for rehabilitation or in the length of stay at home/nursing home, indicating that these factors were not affected by the presence or absence of SRD.
We did find a difference in the effect of SRD according to the type of surgery performed.Among those who were treated with hemiarthroplasty, those with SRD had lower levels of balance before and after rehabilitation than those without SRD.Among those treated with internal fixation of the hip, those with SRD had lower levels of balance and functional abilities as well as more severe hip joint dysfunction before and after rehabilitation than those without SRD.In addition, they had a longer LOS in rehabilitation.All of these results suggest the following to health care professionals: (1) to implement measures capable of counteracting the adverse effects of SRD 16,22 ; (2) to plan longer rehabilitation and to promote exercise programs capable of improving both balance and ADLs in these patients to achieve the preestablished objectives (lower-limb progressive resistance exercises and taskspecific balance training can be also helpful for this purpose) 33,34 ; and (3) to provide higher surveillance at the end of rehabilitation for people with SRD because they have lower levels of balance and functional status and are at greater risk of falling.

LIMITATIONS
Our study has several limitations.SRD was assessed with manual and not instrumental tests.The ROM assessment considered only hip ROM in flexion and abduction, and muscle assessment considered only the strength of flexor and adductor muscles of the hip and the strength of the quadriceps.We performed muscle strength assessment with manual and not instrumental tests, which have a higher level of accuracy and reliability.We did not analyze all the factors that may have influenced outcome measures, such as general postsurgery complications and conditions related to surgical treatment.Moreover, the patients underwent a conventional rehabilitation program and therefore the results may not apply to other programs with different entry criteria.

CONCLUSIONS
This study shows that SRD of the lower limb is associated with lower levels of balance and functional abilities, both before and after rehabilitation, and is a factor that adversely affects the rehabilitation program following hip fracture surgery.These findings may be useful to physicians, physiotherapists, family members, and nurses during rehabilitation for people with hip fractures.
Clinical and demographic characteristics of patients with hip fracture (n = 102) classified according to the presence or absence of SRD of the lower limb T A B L E 1Note: Data are expressed as median (25-75th percentile), or absolute numbers.Comparison between groups was performed by the Mann-Whitney test and chisquare.A p < .05 was considered statistically significant.Abbreviations: CIRS, Cumulative Illness Rating Scale; SRD, shortening and rotational deformity of the lower limb.
T A B L E 2 Outcome measures and clinical variables after rehabilitation in patients with hip fracture according to the presence or absence of SRD of the lower limb Berg Balance Scale at discharge, score 24 (17-28) 16.5 (9-24.5).003Effectiveness in Berg Balance Scale, score 29.9 (17.3-46.1)19.1 (10.7-34.9).034Efficiency in Berg Balance Scale, score 0.38 (0.20-0.71) 0.28 (0.17-0.48) .058 T A B L E 3 Outcome measures and clinical variables in patients who underwent hemiarthroplasty according to presence or absence of SRD of the lower limb Note: Data are expressed as median(25-75th percentile).Comparison between groups was performed by the Mann-Whitney test.A p < .05 was considered statistically significant.Abbreviations: CIRS, Cumulative Illness Rating Scale; FIM, Functional Independence Measure; LOS, length of hospital stay; ROM, range of motion; SRD, shortening and rotational deformity of the lower limb; VNS, Visual Numeric Scale.
T A B L E 4 Outcome measures and clinical variables of patients who underwent hip internal fixation according to presence or absence of SRD of the lower limb Data are expressed as median (25-75th percentile).Comparison between groups was performed by the Mann-Whitney test.A p < .05 was considered statistically significant.Abbreviations: CIRS, Cumulative Illness Rating Scale; FIM, Functional Independence Measure; LOS, length of hospital stay; ROM, range of motion; SRD, shortening and rotational deformity of the lower limb; VNS, Visual Numeric Scale. Note: