Effects of trehalose supplementation on bone healing, physical function, and pain in patients with pertrochanteric fractures: a randomized controlled trial

Abstract

Pertrochanteric fractures are common injuries associated with significant morbidity and delayed healing. Trehalose, a naturally occurring disaccharide with cytoprotective properties, has shown promise in preclinical fracture models. This randomized controlled trial evaluated the effects of trehalose supplementation on radiographic healing, hip function, and pain in patients with pertrochanteric fractures. This double-blind, placebo-controlled trial enrolled 64 patients (aged 18–60 years) with surgically treated pertrochanteric fractures at Taleghani Hospital, Tehran, Iran. Participants were randomly assigned to receive either trehalose (3.3 g/day) or placebo (sucrose) for 12 weeks. The co-primary outcomes were radiographic healing assessed by the Radiographic Union Score for Hip (RUSH) and physical function assessed by the Harris Hip Score (HHS). Secondary outcome was pain intensity assessed by the Visual Analog Scale (VAS). Assessments were conducted at baseline and weeks 2, 4, and 12. Fifty-seven participants completed the study (trehalose n = 28; placebo n = 29). The trehalose group showed significantly higher RUSH scores at week 12 compared with placebo (mean difference 2.09 points; 95% CI 0.45 to 3.72; p = 0.014), with significant group effect (p = 0.050) and group-by-time interaction (p = 0.021). Hip function improved more in the trehalose group, with significantly higher HHS at week 12 (mean difference 8.55 points; 95% CI 3.97 to 13.13; p < 0.001). Pain decreased substantially in both groups with no significant between-group difference.Trehalose supplementation improved radiographic healing and hip function in patients with pertrochanteric fractures. No serious adverse events were reported, but adverse events were not systematically monitored. Larger trials with longer follow-up and structured safety monitoring are needed to confirm these results and evaluate late complications.

Trial registration: Iranian Registry of Clinical Trials. IRCT20240605062013N1. URL of the trial registry record https://irct.behdasht.gov.ir/trial/77212, Registration date 16 June 2024.

Supplementary Information

The online version contains supplementary material available at 10.1038/s41598-026-56086-4.

Introduction

Hip fractures represent a major public health concern, particularly in aging populations. Epidemiologic studies project a substantial increase in hip fracture incidence worldwide over the coming decades^1–3. Despite advances in surgical techniques and perioperative management, hip fractures remain associated with high mortality rates, prolonged disability, and loss of independence^4–7. The economic burden on healthcare systems is considerable, as many patients need extended rehabilitation, frequent re-hospitalization, and long-term institutional care^4,6,8. Beyond achieving surgical stability, optimal outcomes depend on timely bone union, effective pain management, and restoration of physical function.

Pertrochanteric fractures are typically managed with internal fixation using cephalomedullary nails or sliding hip screw devices. Although modern implants provide reliable mechanical stability in most cases, fixation failure and delayed union continue to occur, especially in patients with osteoporotic bone and unstable fracture configurations⁹. Delayed healing prolongs immobility, increases pain, and may necessitate revision surgery in a population with limited physiologic reserve^5–7. Therefore, safe adjunctive interventions that support fracture healing alongside standard surgical fixation remain clinically relevant.

Fracture healing involves a coordinated sequence of inflammatory response, angiogenesis, callus formation, and bone remodeling^10–13. The efficiency of this process is influenced by both mechanical factors (fracture stability and reduction quality) and biological factors (vascular supply, cellular activity, systemic health, and nutritional status)^10–12,14. Advanced age, medical comorbidities, and metabolic stress can impair these steps and increase the risk of delayed union or nonunion^6,10–12. Because many of these risk factors are difficult to modify acutely, there is interest in supportive therapies that are safe, low-cost, and easy to administer after surgery.

Autophagy is a cellular recycling process that removes damaged proteins and organelles and maintains cellular homeostasis under stress conditions^15–18. In bone tissue, autophagy contributes to osteocyte survival and skeletal maintenance¹⁶. Experimental evidence also indicates that autophagy influences osteoclast function and bone remodeling¹⁷, and that autophagy pathways may serve as therapeutic targets in bone metabolic disorders^15,18. These findings suggest that interventions modulating cellular stress responses could potentially influence fracture healing, particularly in the context of major trauma and surgery. Trehalose is a naturally occurring disaccharide that has been studied as a modulator of autophagy and cellular stress pathways^19–21. It is widely used in food and pharmaceutical applications and has demonstrated acceptable safety in regulatory evaluations²². Low-dose oral trehalose regimens have been tested in randomized trials in other patient populations, providing practical data on dosing and tolerability²³. Additionally, trehalose has been investigated in clinical trials for other diseases, further expanding the safety literature²¹. In preclinical fracture models, trehalose administration has shown improvements in radiographic and histologic healing outcomes²⁴. These data provide a rationale for evaluating trehalose as an adjunctive intervention after fracture fixation in clinical studies.

Patient-reported pain is a critical outcome after hip fracture because persistent pain can indicate delayed healing and impair rehabilitation participation²⁵. Pain severity is commonly assessed using the Visual Analog Scale (VAS). Functional recovery is also essential, as early return to mobility and independence is linked to survival and quality of life in this population^6,26. The Harris Hip Score (HHS) is a standardized clinical assessment tool that evaluates pain and hip function²⁶. However, functional scores are influenced by multiple factors beyond bone union, including sarcopenia, frailty, and cardiopulmonary disease^6,10–12. Therefore, radiographic assessment of fracture union remains a necessary complementary endpoint. The Radiographic Union Score for Hip (RUSH) was developed to standardize radiographic healing assessment and has demonstrated improved inter-rater reliability compared with subjective evaluations in hip fracture studies^27,28. Similar structured scoring systems in long-bone fractures have also shown improved consistency and clinical utility in trial settings²⁹. Using RUSH as a primary outcome, combined with patient-centered measures of pain and function, provides a comprehensive approach that addresses both fracture biology and patient recovery.

This randomized, placebo-controlled trial evaluates whether postoperative oral trehalose supplementation can improve radiographic healing after pertrochanteric fracture fixation in working-age adults (18 to 60 years). Consistent with the registered protocol, the co-primary outcomes are radiographic fracture healing assessed by the RUSH score and physical function assessed by the HHS, with pain as a secondary outcome. The study aims to provide clinically relevant evidence on trehalose as a potential adjunctive therapy in hip fracture management.

Materials and methods

Study participants

Sixty-four patients with pertrochanteric femoral fractures were recruited from the orthopedic department of Taleghani Hospital, Tehran, Iran, from December 2024 to December 2025. Participants were included if they met the following criteria: age between 18 and 60 years, diagnosis of pertrochanteric hip fracture requiring surgical fixation, and Injury Severity Score (ISS) less than 15. Exclusion criteria included pregnancy or lactation, unstable hemodynamics, history of autoimmune diseases, active cancer or recent chemotherapy/radiotherapy (within the past month), diabetes mellitus, liver failure, Human Immunodeficiency Virus (HIV) infection, and morbid obesity (Body Mass Index (BMI) > 40 kg/m²). Additional exclusion criteria during the study were lack of willingness to continue participation, significant changes in the treatment process, or Intensive Care Unit (ICU) admission, development of infection, mortality, and intolerance to trehalose. All fractures were classified preoperatively using the AO/OTA system by a senior orthopedic surgeon blinded to group allocation³⁰. Only unstable intertrochanteric fractures (AO/OTA 31-A2, intertrochanteric multifragmentary, and 31-A3, reverse oblique/transverse subtrochanteric) were enrolled; stable 31-A1 fractures were not included.

Sample size was calculated using PASS 2021 software. Based on a clinically important difference of 10 points on the Harris Hip Score³¹, assuming a standard deviation of 10 points, a two-sample t-test with equal variance, 90% power, and 5% significance level, 23 participants per group were required. Accounting for a 30% dropout rate, the final sample size was set at 32 participants per group (64 total).

Study design

This randomized, double-blind, placebo-controlled trial was conducted after obtaining written informed consent from all participants. The study protocol was approved by the Ethics Committee of Shahid Beheshti University of Medical Sciences (SBMU) (IR.SBMU.MSP.REC.1403.150) and registered in the Iranian Registry of Clinical Trials (IRCT20240605062013N1). A detailed study protocol describing the study design, materials, questionnaires, and measurement methods has been published elsewhere³². The study was conducted in accordance with the Declaration of Helsinki. Protocol development and reporting adhered to CONSORT 2010 standards (Fig. 1).

Fig. 1.

Consort diagram of participant flow through the study.

Using permuted block randomization with a computerized random number generator, participants were randomly assigned to intervention (n = 32) and control (n = 32) groups. The allocation sequence was generated by an independent person not involved in enrollment or outcome assessment. Both participants and outcome assessors were blinded to group allocation throughout the study. The supplements and placebo were supplied as powders with identical packaging and coded labels to ensure blinding.

Baseline assessments were performed approximately one day after surgery (week 0), which also served as the intervention start point. Follow-up assessments were conducted at weeks 1, 2, 4, and 12. Pain intensity was assessed at weeks 0, 1, and 2. Radiographic healing (RUSH score) and hip function (HHS) were evaluated at weeks 0, 2, 4, and 12. Week 12 represented the end of the intervention period.

Intervention

The intervention group received 3.3 g/day of trehalose powder (Shaanxi Fruiterco Biotechnology Co., Ltd., purity ≥ 99%) for 12 weeks, while the control group received an identical dose of placebo (sucrose) with the same packaging, color, and appearance. Both powders were dispensed in identical opaque sachets labeled only with a participant identifier and were mixed in water and consumed after breakfast daily at a dose of 3.3 g (less than one teaspoon). Participants were informed only that they would receive a nutritional powder supplement, without disclosure of the chemical identity of either product, and had no access to the comparator or to other participants’ supplements as an internal sweetness reference. All participants received standard postoperative care, including analgesia, thromboprophylaxis, physiotherapy, and rehabilitation counseling. The rehabilitation program was identical in both groups and consisted of mobilization out of bed with a walker on postoperative day 1–2, partial weight-bearing as tolerated using an assistive device during the first 2–4 weeks, and progressive transition to full weight-bearing as tolerated by week 6, guided by radiographic evidence of progressive union and the operating surgeon’s judgment, in accordance with current recommendations for postoperative management of pertrochanteric fractures stabilized with intramedullary fixation³³. Physiotherapists and surgeons involved in postoperative care were blinded to group allocation. All surgical procedures were performed at Taleghani Hospital by experienced orthopedic surgeons. All participants underwent fixation with a proximal femoral nail antirotation (PFNA) under standardized institutional protocols; no extramedullary devices were used.

Adherence to supplementation was monitored through telephone calls and SMS reminders every two weeks. Participants were asked to report any missed doses and to return supplement containers at the end of the study. Low adherence was defined as consumption of less than 80% of the prescribed doses. Participants were also instructed to maintain their usual dietary patterns and physical activity levels throughout the study and to report any potential side effects.

Assessment of variables

Anthropometric measurements, including height and weight, were measured at baseline using a bed scale (Balas company, Iran) with an accuracy of 100 g and a flexible tape with an accuracy of 0.5 cm, respectively. Height was estimated by ulna length when necessary. Body mass index (BMI) was calculated as weight (kg) divided by height squared (m²)³². Dietary intake was assessed at baseline and week 12 using a 24-hour dietary recall questionnaire, which was analyzed using Nutritionist-IV software (version 7.0; N-Squared Computing, Salem, OR, USA).

The first co-primary outcome was radiographic fracture healing assessed using the RUSH, a validated scoring tool that evaluates fracture healing quality in hip fractures^27,28. Standard anteroposterior and lateral pelvis radiographs were obtained at weeks 0, 2, 4, and 12. Radiographs were separately scored by a trained orthopedic resident and a senior orthopedic surgeon, both blinded to treatment allocation. The RUSH score ranges from 10 (no healing) to 30 (complete healing), with higher scores indicating more advanced union.

The second co-primary outcome was physical function, assessed using the HHS; pain intensity was a secondary outcome. Pain was measured using the VAS, a 10-centimeter line where patients marked scores from 0 (no pain) to 10 (worst pain ever experienced)²⁵. VAS was assessed at weeks 0, 1, and 2. Hip function was evaluated using the HHS, which assesses pain, function, range of motion, and deformity, with scores ranging from 0 to 100 (higher scores indicating better function)²⁶. HHS was assessed at weeks 0, 2, 4, and 12.

At baseline, demographic data (age, gender, smoking status, alcohol consumption, and medical history) were collected. The Injury Severity Score (ISS) and Charlson Comorbidity Index (CCI) were used to evaluate trauma severity and medical comorbidities, respectively.

Statistical analysis

Statistical analyses were performed using R (version 4.5.2; R Foundation for Statistical Computing, Vienna, Austria) within RStudio (version 2026.01.0; Posit, Boston, MA, USA). Data normality was assessed using the Kolmogorov-Smirnov test. Continuous variables are presented as mean ± standard deviation (SD), and categorical variables as frequency (percentage). Baseline characteristics were compared between groups using an independent samples t-test for continuous variables and a chi-square test for categorical variables. For non-normally distributed data, the Mann-Whitney U test was used.

To compare the means between the intervention and control groups after adjusting for baseline values and confounding variables (including age, gender, smoking status, BMI, energy intake, and baseline outcome values), analysis of covariance (ANCOVA) was performed. Inter-rater reliability of the RUSH scores between the two independent, blinded evaluators was assessed using the intraclass correlation coefficient (ICC) along with 95% confidence interval (CI) for each time point; scores from both raters were then averaged, and the mean values were utilized in all subsequent analyses (Supplementary Table 1). Paired t-test was used for within-group comparisons (pre- and post-intervention). Missing data were handled using the regression imputation method. Statistical significance was set at p < 0.05.

Results

Of the 64 participants randomized, 57 completed the study and were included in the analysis (trehalose group, n = 28; placebo group, n = 29; Fig. 1). Seven participants discontinued the study due to clinical reasons, including mortality. The mean age of participants was 41.7 ± 13.2 years, and 43 (75.4%) were men. Baseline characteristics were balanced between groups for age, weight, height, BMI, CCI, and ISS (all p > 0.05; Table 1). However, the distribution of AO/OTA fracture classification differed significantly between groups, with a higher proportion of 31-A3 fractures in the trehalose group (64%) than in the placebo group (34%; p = 0.047, Table 1). Baseline pain (VAS) was significantly lower in the trehalose group compared with the placebo group (6.89 ± 1.31 vs. 7.97 ± 0.73; p < 0.001). Baseline Harris Hip Score (HHS) and RUSH score were comparable between groups (Table 1). The ICC values for the RUSH scores were 1.000 (95%CI: 1.000–1.000) at baseline, 0.972 (95%CI: 0.953–0.984) at week 2, 0.943 (95%CI: 0.905–0.966) at week 4, and 0.984 (95%CI: 0.973–0.991) at week 12, which indicated excellent inter-rater agreement (Supplementary Table 1).

Table 1.

Baseline demographic and clinical characteristics of the patients with Pertrochanteric Fractures who received either Trehalose supplements or placebo.

Characteristic	Total (N = 57)	Trehalose (N = 28)	Placebo (N = 29)	p-value
Age (years), mean ± SD	41.7 ± 13.2	40.8 ± 12.7	42.7 ± 13.8	0.590ᵇ
Sex, n (%)				> 0.999ᵃ
Male	43 (75.4)	21 (75.0)	22 (75.9)
Female	14 (24.6)	7 (25.0)	7 (24.1)
Weight (kg), mean ± SD	73.1 ± 13.3	70.9 ± 11.5	75.3 ± 14.7	0.204ᵇ
Height (cm), mean ± SD	173.5 ± 10.2	172.8 ± 9.6	174.2 ± 10.9	0.611ᵇ
BMI (kg/m²), mean ± SD	24.2 ± 3.2	23.7 ± 3.3	24.7 ± 3.1	0.246ᵇ
Diabetes, n (%)	7 (12.3)	3 (10.7)	4 (13.8)	> 0.999ᵃ
Hypertension, n (%)	21 (36.8)	12 (42.9)	9 (31.0)	0.515ᵃ
CCI, mean ± SD	0.88 ± 1.42	0.75 ± 1.43	1.00 ± 1.41	0.367ᶜ
ISS, mean ± SD	14.7 ± 6.0	13.2 ± 5.2	16.2 ± 6.4	0.061ᶜ
AO/OTA classification, n (%)				0.047ᵃ
31-A2	29 (50.9)	10 (35.7)	19 (65.5)
31-A3	28 (49.1)	18 (64.3)	10 (34.5)
Implant type, n (%)				—
PFNA	57 (100)	28 (100)	29 (100)

^a Obtained from Pearson’s Chi-squared test.

^b Obtained from Independent-samples t-test.

^c Obtained from Mann-Whitney U test.

Dietary intake data are summarized in Table 2. Total energy intake and carbohydrate intake differed between groups (group effect p = 0.010 for both). Vitamin D intake showed a significant time-by-group interaction (p = 0.002). Most other nutrients remained stable over time, with no significant differences between groups (Fig. 2).

Table 2.

Dietary intake of the patients with Pertrochanteric Fractures who received either Trehalose supplements or placebo.

Nutrient	Trehalose (Baseline)	Trehalose (12 weeks)	Placebo (Baseline)	Placebo (12 weeks)	P-value
					Timea	Groupb	Time × Groupc
Energy	2043.3 ± 295.9	1980.0 ± 231.5	1838.6 ± 255.8	1863.7 ± 261.9	0.584	0.010	0.209
Carb	261.7 ± 62.2	246.0 ± 33.9	223.8 ± 45.2	229.3 ± 39.2	0.444	0.010	0.118
Protein	57.4 ± 15.0	57.71 ± 9.21	53.7 ± 11.8	53.7 ± 12.5	0.930	0.166	0.931
Fat	88.5 ± 13.1	88.0 ± 15.9	82.5 ± 15.3	84.5 ± 16.1	0.744	0.163	0.588
VitC	70.0 ± 59.6	63.6 ± 28.3	63.6 ± 31.9	52.6 ± 24.6	0.171	0.284	0.718
VitD	22.62 ± 9.14	23.61 ± 8.70	21.77 ± 7.58	20.61 ± 9.16	0.803	0.400	0.002
VitE	26.96 ± 5.34	26.93 ± 6.40	27.17 ± 6.37	26.89 ± 6.09	0.851	0.949	0.878
Selenium	0.029 ± 0.007	0.033 ± 0.013	0.036 ± 0.016	0.042 ± 0.022	0.126	0.004	0.687
Zinc	7.78 ± 1.40	7.54 ± 1.24	7.28 ± 1.34	7.06 ± 1.54	0.304	0.104	0.974
BetaC	903.0 ± 909.3	705.6 ± 635.4	508.5 ± 510.8	614.6 ± 391.0	0.716	0.038	0.230
Fiber	3.79 ± 1.67	3.32 ± 1.22	3.12 ± 1.03	2.938 ± 0.880	0.129	0.041	0.493

Note: All values are presented as means ± SDs.

^aTime effect; obtained from two-way mixed measures ANOVA.

^bGroup effect; obtained from two-way mixed measures ANOVA.

^cTimegroup interaction; obtained from two-way mixed measures ANOVA.

Fig. 2.

Comparisons of pain of the patients with Pertrochanteric Fractures who received either Trehalose supplements or placebo.

Radiographic healing improved progressively in both groups over the 12-week follow-up period (Table 3; Fig. 3). Baseline RUSH scores were 10.00 ± 0.00 in both groups. At week 2, mean RUSH scores were 15.61 ± 3.00 in the trehalose group and 15.24 ± 2.21 in the placebo group. At week 4, scores increased to 20.71 ± 2.68 and 19.41 ± 2.76, respectively. At week 12, the trehalose group achieved a mean score of 27.50 ± 1.77 compared with 25.41 ± 3.96 in the placebo group. Repeated-measures ANOVA showed a significant time effect (p < 0.001), group effect (p = 0.050), and group-by-time interaction (p = 0.021). The between-group difference at week 12 was 2.09 points (95% CI 0.45 to 3.72; p = 0.014), favoring the trehalose group. After adjusting for baseline RUSH score and fracture type using ANCOVA, there were no significant differences between the trehalose and placebo groups at 2 weeks (adj. p = 0.389) or 4 weeks (adj. p = 0.122); however, a significant difference favoring the trehalose group emerged at 12 weeks (adj. p = 0.023).

Table 3.

Comparisons of clinical outcomes of the patients with Pertrochanteric Fractures who received either Trehalose supplements or placebo.

Outcome	Trehalose							Placebo							P-value
	Baseline	2 wk	4 wk	12 wk	Δ 2 wk	Δ 4 wk	Δ 12 wk	Baseline	2 wk	4 wk	12 wk	Δ 2 wk	Δ 4 wk	Δ 12 wk	Timea	Groupb	Time × Groupc	Adj. P-value 2wkd	Adj. P-value 4wkd	Adj. P-value 12wkd
HHS	8.21 ± 7.72	45.71 ± 14.41	67.18 ± 13.46	91.93 ± 6.18	37.50 ± 16.11	58.96 ± 14.48	83.71 ± 8.14	5.17 ± 6.34	42.83 ± 14.64	59.72 ± 14.02	83.38 ± 10.52	37.66 ± 13.70	54.55 ± 12.01	78.21 ± 9.41	< 0.001	0.022	0.181	0.456	0.143	0.008
WHI	9.57 ± 0.74	18.54 ± 1.00	20.86 ± 1.21	26.50 ± 0.51	8.96 ± 0.96	11.29 ± 1.56	16.93 ± 0.72	9.31 ± 0.89	16.10 ± 1.08	20.34 ± 1.29	26.48 ± 0.51	6.79 ± 1.15	11.03 ± 1.72	17.17 ± 1.10	< 0.001	< 0.001	< 0.001	< 0.001	0.095	0.993
RS	10.00 ± 0.00	15.70 ± 2.93	20.79 ± 2.65	27.39 ± 1.81	5.70 ± 2.93	10.79 ± 2.65	17.39 ± 1.81	10.00 ± 0.00	15.28 ± 2.18	19.40 ± 2.74	25.43 ± 3.98	5.28 ± 2.18	9.40 ± 2.74	15.43 ± 3.98	< 0.001	0.050	0.027	0.389	0.122	0.023

Note: All values are presented as means ± SDs.

Abbreviations: Δ = change from baseline; HHS: Harris Hip Score; WHI; wound healing index; RS: RUSH Score.

^aTime effect; obtained from two-way mixed measures ANOVA.

^bGroup effect; obtained from two-way mixed measures ANOVA.

^cTime group interaction; obtained from two-way mixed measures ANOVA.

^d Adjusted P-value for the between-group comparison at 2, 4, and 12 weeks after controlling for baseline scores and fracture type.

Fig. 3.

Comparisons of clinical outcomes of the patients with Pertrochanteric Fractures who received either Trehalose supplements or placebo. Abbreviation: HHS: Haris Hip score, RS: RUSH score.

Hip function improved markedly in both groups throughout the follow-up period (Table 3; Fig. 3). In the trehalose group, mean HHS increased from 8.21 ± 7.72 at baseline to 45.71 ± 14.41 at week 2, 67.18 ± 13.46 at week 4, and 91.93 ± 6.18 at week 12. In the placebo group, mean HHS increased from 5.17 ± 6.34 at baseline to 42.83 ± 14.64, 59.72 ± 14.02, and 83.38 ± 10.52 at weeks 2, 4, and 12, respectively. Repeated-measures ANOVA demonstrated a significant time effect (p < 0.001) and group effect (p = 0.022), but no significant group-by-time interaction (p = 0.181). At week 4, the mean difference between groups was 7.45 points (95% CI 0.16 to 14.75). At week 12, the trehalose group showed significantly higher HHS compared with the placebo group (mean difference 8.55 points; 95% CI 3.97 to 13.13; p < 0.001). After adjusting for baseline HHS and fracture type using ANCOVA, there was no significant difference between groups at 2 weeks (adj. p = 0.456) or 4 weeks (adj. p = 0.143), but the trehalose group showed significantly better hip function at 12 weeks (adj. p = 0.008).

Pain intensity decreased over time in both groups (Table 4; Fig. 2). In the trehalose group, mean VAS scores declined from 6.89 ± 1.31 at baseline to 3.07 ± 1.90 at week 1 and 1.29 ± 0.66 at week 2. In the placebo group, mean VAS scores decreased from 7.97 ± 0.73 at baseline to 3.62 ± 1.45 at week 1 and 1.55 ± 0.69 at week 2. Repeated-measures ANOVA showed a significant time effect (p < 0.001) and group effect (p = 0.004), but no significant group-by-time interaction (p = 0.172). At week 2, the between-group difference was − 0.27 points (95% CI − 0.62 to 0.09; p > 0.05), indicating comparable pain levels in both groups at the end of the follow-up period. After adjusting for baseline VAS score and fracture type using ANCOVA, there were no significant differences in pain between the trehalose and placebo groups at either 1 week (adj. p = 0.329) or 2 weeks (adj. p = 0.351).

Table 4.

Comparisons of pain of the patients with Pertrochanteric Fractures who received either Trehalose supplements or placebo.

Outcome	Trehalose					Placebo					P-value
	Baseline	1 wk	2 wk	Δ 1ωκ	Δ 2ωκ	Baseline	1 wk	2 wk	Δ 1ωκ	Δ 2ωκ	Timea	Groupb	Time × Groupc	Adj. P-value 1wkd	Adj. P-value 2wkd
Pain Score	6.89 ± 1.31	3.07 ± 1.90	1.29 ± 0.66	-3.82 ± 2.31	-5.61 ± 1.31	7.97 ± 0.73	3.62 ± 1.45	1.55 ± 0.69	-4.34 ± 1.56	-6.41 ± 1.05	< 0.001	0.004	0.172	0.329	0.351

Note: All values are presented as means ± SDs.

Abbreviations: Δ = change from baseline.

^aTime effect; obtained from two-way mixed measures ANOVA.

^bGroup effect; obtained from two-way mixed measures ANOVA.

^cTime group interaction; obtained from two-way mixed measures ANOVA.

^d Adjusted P-value for the between-group comparison at 1 and 2 weeks after controlling for baseline VAS score and fracture type.

Discussion

In this randomized, placebo-controlled trial of adults with pertrochanteric hip fractures, we found that trehalose supplementation improved radiographic healing compared with placebo over 12 weeks. The trial protocol was published previously³². The primary outcome, RUSH score, showed a significant group effect and group-by-time interaction, with higher scores in the trehalose group at week 12. Hip function (HHS) also improved more in the trehalose group, with a significant between-group difference at the end of the intervention period. Pain intensity decreased substantially in both groups, with no significant difference in pain trajectory between groups.

The improvement in radiographic healing is the main finding of this study. We used the RUSH score, a validated tool that improves reproducibility in assessing hip fracture healing²⁸. Baseline RUSH scores were identical in both groups, and the divergence occurred progressively over time, with the largest difference observed at week 12. This pattern is consistent with an intervention that may support callus maturation and bone remodeling rather than early inflammatory processes^11,12,14. Trehalose has not been previously tested in fracture healing, but our radiographic findings can be compared with other interventions studied in this population. Tanavalee et al. evaluated teriparatide in 50 patients undergoing pertrochanteric fracture fixation and found significantly shorter bone union time in the treatment group compared with placebo³⁴. Similarly, Huang et al., in a retrospective study of 73 patients with unstable pertrochanteric fractures, reported that teriparatide-treated patients showed faster fracture healing and reduced rates of lag screw sliding and varus collapse compared with controls³⁵. However, not all studies of bone-active agents have shown benefit in fracture healing. Bhandari et al. conducted a multicenter randomized trial in 159 patients with femoral neck fractures and found no improvement in revision surgery rates, radiographic healing, or pain scores with teriparatide compared with placebo³⁶. This highlights that treatment effects may differ by fracture pattern, fixation method, and underlying bone biology. Colón-Emeric et al. in the HORIZON trial evaluated zoledronic acid in over 2,000 hip fracture patients and found that early administration did not impair fracture healing, supporting the broader point that systemic bone-active agents may be safe in the peri-fracture period even if they do not accelerate union³⁷.

Nutritional interventions have also been investigated as potential adjuncts to fracture healing. A systematic review by Gatt et al. evaluated vitamin D supplementation in fracture patients and found that vitamin D alone does little to influence fracture healing or union rates, with most studies showing no significant differences in functional outcomes³⁸. Similarly, Slobogean et al. in a phase II trial comparing multiple vitamin D3 dosing strategies in long bone fracture patients found no differences in radiographic or clinical healing across groups³⁹. In contrast to its limited role in fracture healing, vitamin D supplementation has demonstrated benefit for fracture prevention, with doses of 700–800 IU daily reducing hip fracture risk in elderly populations⁴⁰. Protein-rich oral nutrition supplements have also been studied in hip fracture patients, with some trials reporting modest improvements in wound healing but no consistent effects on functional recovery⁴¹. To our knowledge, this is the first randomized trial evaluating trehalose supplementation in fracture healing. While the radiographic improvement is encouraging, longer follow-up is needed to assess clinically relevant endpoints such as time to full weight-bearing, reoperation rates, and incidence of delayed union or nonunion.

Hip function improved substantially in both groups, with mean HHS increasing from baseline to over 83 points at week 12. The trehalose group showed significantly higher HHS scores at the end of the intervention period. The HHS is widely used and combines clinician assessment and patient-reported components, and improvements reflect both bone healing and overall functional recovery, including muscle strength, mobility, and pain control^26,42. Yu et al., in a long-term follow-up study of 222 patients with stable intertrochanteric fractures treated with either PFNA or DHS, found good functional recovery in both groups, with no clinically meaningful differences in final HHS scores despite differences in reoperation rates⁴³. Similarly, Shen et al. in a meta-analysis of randomized trials comparing PFNA with DHS found no significant difference in HHS between implant types, although PFNA showed fewer complications and lower reoperation rates⁴⁴. Moroni et al., in a randomized trial of 40 elderly women with osteoporotic pertrochanteric fractures, compared DHS with external fixation and reported comparable Harris hip scores at 6 months in both groups⁴⁵. These studies demonstrate that functional outcomes are shaped by multiple factors beyond the specific intervention, including perioperative care, rehabilitation intensity, and patient characteristics.

Pain intensity decreased rapidly in both groups during the first two weeks post-surgery. We found no significant difference in pain trajectory between groups. Baseline pain was significantly lower in the trehalose group, which likely resulted from random variation despite randomization. This baseline imbalance limits the interpretation of between-group pain comparisons. Pasquier et al. in a randomized trial of 30 hip fracture patients found that fascia iliaca block did not provide additional analgesic benefit when baseline pain scores were already low following prehospital morphine administration⁴⁶. In contrast, Foss et al. in a double-blind trial of 48 patients reported superior pain relief with fascia iliaca block compared with intramuscular morphine, with reduced total opioid consumption⁴⁷. Additionally, pain after fracture surgery is influenced by multiple factors beyond bone healing, including surgical technique, analgesic use, and early mobilization^48–51.

The mechanisms by which trehalose may improve fracture healing are not fully understood. Trehalose is a naturally occurring disaccharide with demonstrated cytoprotective properties in various tissues and has been widely used in food and pharmaceutical applications^22,52,53. Preclinical studies suggest that trehalose modulates cellular stress responses, including autophagy pathways, often described as an mTOR-independent autophagy enhancer^19,54. Autophagy is a cellular process that removes damaged proteins and organelles and is involved in cellular quality control and adaptation to stress, with broad relevance to tissue repair^55–57. In fracture healing, many cells operate in a fluctuating microenvironment with hypoxia, oxidative stress, and high metabolic demand, especially early after trauma and surgery^11,12,14,58. Theoretically, an intervention that helps cells tolerate stress and maintain function could support callus formation and maturation. However, the translation of preclinical autophagy findings to clinical fracture healing remains uncertain. Much of the trehalose-autophagy evidence comes from models of neurodegenerative protein clearance and other non-skeletal contexts^19,54, and the dose-response relationships and tissue-specific effects in humans are not well characterized. Future studies incorporating mechanistic endpoints could help elucidate the pathways through which trehalose influences fracture healing.

Dietary intake differed between groups, with the trehalose group reporting higher total energy and carbohydrate intake and a significant time-by-group interaction for vitamin D. Because nutritional status can influence both fracture healing and functional recovery, this imbalance represents a potential confounder, and its direction, with higher intake in the trehalose group, could in principle have contributed to the more favorable RUSH and HHS outcomes observed in that group. Two factors partially mitigate this concern: the primary analyses were adjusted for energy intake using ANCOVA, and protein intake, the macronutrient most directly relevant to fracture healing and functional recovery, did not differ between groups. Nevertheless, carbohydrate, vitamin D, and several micronutrients were not fully accounted for in the adjusted models, and residual nutritional confounding cannot be excluded; this is relevant because deficiency of nutrients such as vitamin D is common in fracture populations, although trial evidence for accelerated union is mixed^39,59,60. Future trials should more comprehensively standardize or measure dietary intake and nutritional biomarkers, including serum vitamin D.

Strengths and limitations

This study has several strengths. The randomized, double-blind, placebo-controlled design minimizes bias and enhances the reliability of our findings. We used validated assessment tools, including the RUSH score for radiographic healing, VAS for pain, and HHS for hip function^{25–27,42,61}. Repeated measurements at multiple time points allowed us to assess healing trajectories over 12 weeks. Both participants and outcome assessors were blinded to treatment allocation throughout the study, reducing the risk of assessment bias.

Several limitations should be considered when interpreting our findings. The primary limitation is the absence of systematic adverse event monitoring: although trehalose has an established safety profile in food and pharmaceutical contexts^22,52,53, gastrointestinal symptoms were not prospectively captured using a structured instrument, and the present data do not permit firm conclusions regarding the safety or tolerability of trehalose at this dose and duration. The sample size was also relatively small (n = 57), which limits statistical power and generalizability; seven participants (11%) discontinued due to clinical reasons, including mortality. The study population comprised working-age adults (18–60 years, predominantly male) rather than typical elderly fragility fracture patients, and the findings should not be extrapolated to patients with osteoporotic hip fractures. The follow-up period of 12 weeks is insufficient to detect late-onset complications such as nonunion or implant failure, and the present findings should be regarded as early radiographic observations only. Baseline pain (VAS) was significantly lower in the trehalose group, which limits the interpretation of between-group pain comparisons. Dietary intake differed between groups for energy, carbohydrate, and vitamin D, which may have confounded the results; we did not exclude commercial products that may contain trehalose as a food additive or separately quantify background dietary trehalose intake, although trehalose is not in routine use in Iranian food manufacturing. Although the trehalose and placebo were matched for appearance, color, smell, and packaging and administered at a small daily dose with the morning meal, no specific taste-masking agent was added and formal post-study assessment of blinding integrity was not performed. Finally, we did not assess quality of life, return to work, or patient-reported satisfaction, which are important patient-centered outcomes. Future trials should incorporate longer follow-up, structured safety and adverse event monitoring, formal blinding-integrity assessment, dietary restriction of trehalose-containing products with biochemical confirmation of exposure, and assessment of patient-reported outcomes.

Clinical implications and future directions

Hip fractures remain a major contributor to disability, health service utilization, and mortality worldwide, and even modest improvements in recovery could have an important clinical impact^1,3,6,8. While much of the global burden is concentrated in older adults, hip fractures in younger or middle-aged adults also occur and can carry important functional and socioeconomic consequences, particularly in working-age populations^48–51,62. In extracapsular fractures, surgical technique and implant choice are central, but there is continued interest in safe adjunctive strategies that might support bone healing^48–51. Our findings suggest that trehalose supplementation may improve radiographic healing and hip function in patients with pertrochanteric fractures. However, these results should be considered preliminary. As the trial enrolled working-age adults, these findings require confirmation before being generalized to elderly patients with osteoporotic fractures. Fracture healing biology differs in elderly patients (reduced osteoblast activity, impaired vascularization, age-related autophagic decline, and higher comorbidity burden). Although trehalose’s autophagy-modulating mechanism could be particularly relevant in this context, this hypothesis remains untested, and dedicated trials in geriatric fragility fracture patients are needed before clinical recommendations can be made for this population. Larger, multicenter trials are needed to confirm these findings and to assess clinically important outcomes such as time to full weight-bearing, delayed union rates, reoperation rates, and return to work. Future studies should also include longer follow-up periods (at least 6–12 months), comprehensive safety monitoring, and cost-effectiveness analyses. If confirmed in larger trials with structured safety monitoring, trehalose could represent a low-cost adjunctive intervention to support fracture healing in clinical practice.

Conclusion

This randomized, placebo-controlled trial demonstrated that trehalose supplementation improved early radiographic healing and hip function in patients with pertrochanteric fractures. Pain decreased substantially in both groups, with no significant difference between treatment arms. These findings should be regarded as preliminary, early-recovery observations; no serious adverse events were reported, but adverse events were not systematically monitored. Larger, multicenter trials with longer follow-up and structured safety monitoring are needed to confirm these results and establish the clinical significance, long-term outcomes, and safety profile of trehalose in fracture management.

Supplementary Information

Below is the link to the electronic supplementary material.

Abbreviations

ANCOVA

Analysis of Covariance

ANOVA

Analysis of Variance

BMI

Body Mass Index

CCI

Charlson Comorbidity Index

ICC

Intraclass Correlation Coefficient

CI

Confidence Interval

CONSORT

Consolidated Standards of Reporting Trials

HHS

Harris Hip Score

HIV

Human Immunodeficiency Virus

ICU

Intensive Care Unit

IRCT

Iranian Registry of Clinical Trials

ISS

Injury Severity Score

RUSH

Radiographic Union Score for Hip

SBMU

Shahid Beheshti University of Medical Sciences

SD

Standard Deviation

SMS

Short Message Service

VAS

Visual Analog Scale

PFNA

Proximal Femoral Nail Antirotation

Author contributions

Conceptualization: R.Z., H.Z., and S.T.; Methodology: R.Z. and H.Z.; Formal Analysis: H.Z. and H.A.; Investigation: H.O.R., A.T.Z., M.M., S.N., and H.Z.; Resources: A.M. and A.S.; Data Curation: H.O.R. and A.T.Z.; Writing – Original Draft: M.R.J. and H.O.R.; Writing – Review & Editing: H.Z., A.T.Z., M.R.J., and A.S.; Visualization: H.O.R.; Supervision: R.Z., H.Z., and S.T.; Project Administration: S.T., H.Z., and R.Z.; Funding Acquisition: A.M. All authors have read and approved the final manuscript.

Funding

This present research was supported by the SBMU grant no. 43009363.

Data availability

On reasonable request, the corresponding author will provide the datasets used and analyzed during the current work.

Declarations

Competing interests

The authors declare no competing interests.

Ethics approval and consent to participate

Initially, each patient received the necessary information regarding the research objective and structure. All patients provided written informed consent for study participation. The collected data and samples were identified by aliases for future use. This study was performed according to the Declaration of Helsinki. The research protocol received approval from the Bioethics Committee of SBMU on May 21, 2024 (IR.SBMU.MSP.REC.1403.150).

Patient and public involvement

Patients and/or the public were not involved in the design, conduct, reporting, or dissemination plans of this research. Refer to the Methods section for further details.