CLINICAL APPLICATION OF A NOMOGRAM TO ASSESS THE RISK OF COMPLICATIONS IN PATIENTS WITH A PROXIMAL FEMORAL FRACTURE Yakubdzhanov R.R., Karimov, M.Yu., Akhtyamov I.F., Madrakhimov S. B.

Tashkent Medical Academy, Tashkent, Uzbekistan

Kazan State Medical University, Kazan, Russia

The incidence of proximal femur fractures (PFF) is about 1.6 million each year, and this number increases by 25 % each 20 years due to increasing population [1]. In the developed countries, their incidence is high, but stable, that is possibly related to improvement in diagnostics and treatment of osteoporosis in older patients [2, 3]. According to predicted estimates, along with increasing life span and percentage of older people, the total amount of such fractures will increase to 4.5 million in 2050 [4]. Moreover, proximal femur fractures are associated with high incidence of postsurgical complications. One-third of older patients with PFF dies within a year after trauma, resulting in high socioeconomic losses for individuals and society [1, 2, 5, 6].

The literature describes a lot of factors relating to high risk of death after PFF, as well as predictive values of postsurgical risk of complications [7-10]. However, these values do not consider presurgical condition to the proper degree, they require for excessive information and/or are heavy to use (they do not cover all aspects of determination of strategy of surgical intervention or non-intervention, practical use of which is very limited). Therefore, the approaches are needed which can objectively estimate and predict the rate of postsurgical complications and decrease the postsurgical risk in patients with PFF.

A group of Russian specialists, headed by professor V.V. Agadzhanyan, developed a nomogram [12, 13] for predictive estimation of development of such postsurgical complications, with consideration of such parameters as age, gender, concurrent diseases, general condition severity according to ASA (American Society of Anesthesiologists [11]) classification, and a fracture type. According to the authors' opinion, the next stage is selection of a strategy of surgical management of PFF to decrease the risk of postsurgical complications [14]. The project resulted in a study of clinical use of the prediction model of the risk of postsurgical complications by means of analysis of complications, treatment duration, functional results and mortality from this injury in Kuzbass region [15].

The objective of this study − to evaluate the clinical results of using a nomogram to predict the risk of complications in patients with a proximal femoral fracture.

MATERIALS AND METHODS

A retro-prospective single-center study analyzed the outcomes of treatment of proximal femur fractures in 65 patients who had addressed to the Multi-profile Clinic of Tashkent Medical Academy from January, 2017, to December, 2019. These patients consisted the main group. The comparison group included 102 patients with PFF treated in our clinic from January, 2014, to December, 2016. The information was taken from the medical archive and analyzed retrospectively.

The inclusion criteria were the age > 18, ISS < 15, full period of stay in our clinic (without transfer to others), and hospital stay more than 24 hours.

The study was approved by the ethical committee of Tashkent Medical Academy. The informed consent was received from each patient. All procedures with participation of patients corresponded to Helsinki Declare 1964 with its subsequent corrections or to similar ethical standards.

The table 1 presents the main characteristics of demographic and clinical parameters of patients with PFF at admission: age (18-64 − young, 65 and > − older), gender, comorbidity status (0, 1-2, 3+ concurrent chronic diseases), ASA classification (severity class of general condition). A fracture type (intraarticular − subcapital, transcervical, basicervical; extraarticular − transtrochanteric, subtrochanteric) and a type of surgical intervention (osteosynthesis or arthroplasty). Duration of hospital stay in pre- and postsurgical periods was considered for each patient individually. Estimation of optimized preparation of the patient to surgery was conducted with the nomogram developed by our Russian colleagues, for each gender separately [12, 13]. Proximal femur fractures were diagnosed according to ICD-10 on the basis of routine clinical studies, radial diagnosis, multi-spiral computer tomography (MSCT), if verification was required.

According to the risk of postsurgical complications, the groups of patients were distributed: low risk − < 10 %, average risk − 10-30 %, high risk − > 30 % [12, 13]. A type of surgical intervention with osteosynthesis (intramedullary nail, cannulated screws, pins) and arthroplasty of the hip was determined by a fracture type and the risk of postsurgical complications.

The functional results of treatment were estimated with Harris Hip Score, which is the most reliable for such injuries [16, 17].

The statistical analysis was conducted with Microsoft Excel (Redmond, WA, USA) and SPSS Statistics software (version 22, IBM, Armonk, NY, USA). The quantitative results are presented as mean arithmetic (M) and mean value ± SD in variation range in view of Me (LQ-UQ), where Me − the median, (LQ-UQ) − interquartile range (LQ − 25 %, UQ − 75 %). Student's test was used for estimation of statistical significance of intergroup differences. Chi-square test was used for estimation of significance of differences in monitoring frequency. The critical level of significance (α) was 0.05.

RESULTS

According to demographic, clinical and physical data of patients with PFF in both groups (the main group − 65 patients, the comparison group − 102 patients), the patients' characteristics had quite high degree of compliance. The table 1 shows the main characteristics of the patients. According to fracture type, intraarticular fractures prevailed in the main and control groups (70.7 % and 67.6 % correspondingly). Extraarticular fractures were 29.2 % and 32.3 % in the main group and in the controls correspondingly.

Table 1

Main characteristics of patients with fractures of the proximal femur

	Main group (n = 65)		Control group (n = 102)		χ2	Р¹
	abs.	%	abs.	%
Age, years
18-64 years	18	27.7	27	26.5	0.03	0.862
65+ years	47	72.3	75	73.5	0.03	0.862
Gender
male	22	33.8	36	35.3	0.04	0.848
female	43	66.2	66	64.7	0.04	0.848
ISS²points, M (SD)³	13 (9.7)		14 (9.9)		1.15	0.283
Type of fracture
intraarticular	46	70.8	69	67.6	0.18	0.671
subcapital	13	20	22	21.6	0.06	0.808
transcervical	24	36.9	35	34.3	0.12	0.7309
basicervical	9	13.8	12	11.8	0.16	0.6924
extraarticular	19	29.2	33	32.4	0.18	0.671
transtrochanteric	15	23.1	25	34.5	0.04	0.8325
subtrochnteric	4	6.2	8	7.8	0.17	0.6802
Comorbidity level (before trauma)
no concurrent diseases	4	6.2	8	7.8	0.17	0.6802
1-2 concurrent diseases	38	58.5	57	55.9	0.11	0.7428
3+ concurrent diseases	24	36.9	37	36.3	0.01	0.9324
ASA⁴ physical status class
-1	7	10.8	12	11.8	0.04	0.8434
-2	15	23.1	25	24.5	0.04	0.8325
-3	27	41.5	43	42.2	0.01	0.9371
-4	16	24.6	22	21.6	0.21	0.647

Notes: 1 − probability of absence of differences in groups, 2 − Injury Severity Score, 3 − mean value (standard deviation), 4 − American society of anesthesiologists.

The risk of postsurgical complications in patients of the main group was estimated with the nomogram with consideration of age, gender, comorbidity status, ASA severity class, a fracture type for men and women separately [13]. The risk groups distributed in the following manner: low risk (< 10 %) − 7 patients (10.82 %), average risk (10-30 %) − 41 patients (63.07 %), high risk (> 30 %) − 17 patients (26.1 %) (the table 2). The values of primary estimation of the risk of possible development of postsurgical complications did not show any significant differences in the risk groups in the main and control groups (the table 2).

Table 2

Characteristics of indicators of prognostic risk of complications in patients with fractures of the proximal femur

	Main group (n = 65)		Control group (102)		χ2	Р*
	abs. (%)		abs. (%)		χ2	Р*
Prognostic risk of complications	At admission	re-evaluation before surgery	At admission
- low	7 (10.8)	10 (15.4)	11 (10.8)		0	0.998
- moderate	41 (63.1)	44 (67.7)	62 (60.8)		0.09	0.766
- high	17 (26.1)	11 (16.9)	29 (28.5)		0.1	0.748
Surgery	abs.	%	abs.	%
total hip replacement	12	18.5	14	13.7	0.68	0.41
Osteosynthesis	53	81.5	88	86.3		0.41
fixation with cannulated screws	18		26		0.68
fixation with pins	8		15		0.1
intramedullary fixation with PFN	17		34		0.19
plate for proximal hip	10		13		0.96
Postsurgical complications
Lower extremity deep vein thrombosis	4	6.2	12	11.8	1.44	0.23
Superficial infection of wound	1	1.5	2	2	0.04	0.841
After osteosynthesis
Metal migration	2	3.1	7	6.9	1.12	0.291
Superficial infection of wound	1	1.5	3	2.9	0.33	0.563
Length of stay, days, Me (IQR)	17.2 (10.3-22.0)		14.6 (7.6-18.0)

Note: the risks are calculated using a nomogram developed by Russian colleagues (Agadzhanyan V.V. et al), * – compared to the control group
Abbreviations: PFN – proximal female nailing, Me (IQR) – median (interquartile range).

In the main group, the patients with high risk (n = 17) were treated with conservative techniques for cardiologic, endocrinologic and neurological concurrent pathology to optimize the somatic status. On average, the patients were observed by cardiologist, endocrinologist, therapeutist and neuropathologist during 5 days (average amount of presurgical days − 5.2 (1.8)). After optimization of the somatic status, the recurrent estimation of the risk of postsurgical complications showed the following distribution: low risk (< 10 %) − 10 patients (15.4 %), average risk (10-30 %) − 44 patients (67.7 %), high risk (> 30 %) − 11 patients (16.9 %) (the table 2). Therefore, the amount of patients with high risk decreased 1.54 time (χ2 = 30.2, р < 0.05) by means of distribution into the groups of lower risk, including the low risk group. When applicable, selection of a type of surgical intervention is realized with our Russian colleagues' method for selection of a surgical strategy for proximal femur fractures [14].

A method of surgical intervention was based on fracture types. Total hip replacement, cannulated screws and pins were used for intraarticular fractures. Intramedullary osteosynthesis with locked PFN, and angle stability plates for proximal femur were used for extraarticular fractures. The table 2 presents the amount of operations and methods of surgical intervention.

Primary total arthroplasty was conducted for 18.5 % of patients in the main group and for 13.7 % for the comparison group. Therefore, one or other type of osteosynthesis was conducted for 81.5 % of patients in the main group and for 86.3 % of patients in the control group (the table 2).

The patients who received total hip replacement had the following complications: deep venous thrombosis in the lower extremities in one case in the main group (treated with conservative methods), superficial infection in the surgical intervention site in two patients in the comparison group (good results after antibiotic therapy).

The following complications were identified after osteosynthesis: migration of a metal construct in 2 and 7 cases correspondingly. Describing this type of complications, we should note than the main group included only one case of migration of the distal screw (intramedullary osteosynthesis) and one case of migration of one of three cannulated screws. The comparison group included 3 cases of migration of a pin in fascicular osteosynthesis, 2 cases of migration of 1 of 3 cannulated screws, 2 cases of migration of screws in intramedullary osteosynthesis. 1 of 3 cases showed a superficial infection of the surgical wound (after plate osteosynthesis and pin fixation; positive result of antibiotic therapy).

The postsurgical complications in patients with PFF were 6.15 % in the main group and 11.76 % in the comparison group. The ratio of amount of complications was 1.91/1.0 (p = 0.05). There were not any lethal outcomes.

General duration of stay in the clinic was 17.2 (10.3-22) in the main group, and 14.6 (7.6-18) in the comparison group (the table 2). It was associated with necessity of correction of somatic status before surgery.

Recurrent installment of the cannulated screw was performed only in one case in the main group. In the comparison group, 3 cases of pin migration were corrected with removal of the single migrated pin without recurrent introduction due to stability of osteosynthesis and bed rest. All cases of osteosynthesis were consistent. Perisurgical one-year deaths were absent.

12 months after surgical intervention, the functional results were estimated with Harris Hip Score in 59 (90.7 %) patients of the main group and in 93 (91.1 %) patients in the comparison group (the table 3). Excellent results were observed in 13 (22.03 %) of patients in the main group and in 16 (17.20 %) in the comparison group. The difference was 1.29 time (χ2 = 0.55, p = 0.460). Good results were 1.43 time higher in the main group (χ2 = 3.35, p = 0.067) (the table 3).

Table 3

Functional results of treatment of patients with proximal femur fracture, Harris Hip Score (1969), 1 year postoperative period

Results	Main group (n = 59)		Control group (n = 93)		χ2*	Р**
Results	abs	%	abs	%
Fine	13	22	16	17.2	0.55	0.46
Good	35	59.3	41	44.1	3.35	0.067
Satisfactory	11	18.6	36	38.7	6.8	0.009
Unsatisfactory	-		-
Total	59	100	93	100

Note: * – comparison of groups with χ2, ** - p < 0.05.

DISCUSSION

The proximal femur fracture is a common injury in older patients. They have high risk of postsurgical complications, which are fatal in most cases: thromboembolic, congestive, infectious. Osteosynthesis failure causes the revision interventions and even more severe consequences. If the patient's somatic status allows, a surgical intervention must be conducted as early as possible [18, 19]. However, older patients often had concurrent diseases, and the use of simple predictive model of the risk of possible postsurgical complications with the nomogram is a simple and non-expensive method since perisurgical estimation can be difficult. Therefore, in this study, we tried to estimate the possibility of efficient clinical use of the nomogram in patients with PFF.

Our results confirmed the conclusions of the developers that the nomogram allows fast distribution of patients into the risk groups (low, average, high) that is efficient for prediction of possible postsurgical complications. In 2019, the authors of the nomogram published a study [15] with estimation of its clinical use. According to the results, some values are quite comparable with ones in our study. So, the use of the nomogram resulted in 1.7-fold decrease in amount of complications, 1.3-fold decrease in hospital stay. Fine functional results improved two times, good results − 1.4 time [15]. Our results are similar with results of the authors only in some aspects. So, in our study, the amount of complications decreased 1.91 time, and the amount of excellent and good functional results increased 1.29 and 1.43 times correspondingly.

However, the total duration of hospital stay increased 1.17 time in the main group. Probably, it was related to time consumption for optimization of patients' condition in high risk of postsurgical complications.

We should note the features of the system and approaches to treatment of PFF in Uzbekistan. Very often, the evident advantages of one of treatment variants can be selected as the priority since the absence of insurance medicine dictates own economic laws in treatment of patients. Therefore, selection of a surgical technique was based not only on risks of postsurgical complications, but also on financial issues. As result, a decrease in possible risks of postsurgical complications and improvement in functional results were achieved with limited adherence to this algorithm that determines the necessity of inclusion of this component into future calculations.

Currently, there are few predictive estimates which include presurgical condition of the patient and stress from surgical invasion. The literature describes E-PASS (Estimation of Physiologic Ability and Surgical Stress, which consists of PRS (Presurgical Risk Score) and SSS (Surgical Stress Score)), which was initially developed for abdominal surgery to predict the postsurgical risk (considering the presurgical condition of the patient and intrasurgical variables [20]), and was used for estimation of patients with PFF [10]. The use of these formulae in clinical practice, when a decision is made urgently, does not require for expensive equipment and can be registered in any medical facility.

We understand that our study has some limitations. First of all, patients of the comparison group were included retrospectively. Moreover, one-year mortality from trauma was not registered in any patient. The possible reason is relatively low amount of patients in the study group. Therefore, in relation to one-year mortality, the studied groups were non-objective for normal population with proximal femur fractures [21]. Moreover, the variations used in a study by Ustyantsev et al. [15] are quite applicable for our study.

We should note the necessity for more detailed estimation of predictive ability, considering the existing differences at the level of medical technologies, characteristics of Uzbekistan population, and the country where this method of predictive estimation of the risk of postsurgical complications has been developed.

CONCLUSION

The results of our study confirm the efficiency of the nomogram for predictive estimation of the risk of possible complications in patients with proximal femur fractures.

This method of the use of the nomogram allows inclusion of various specialists for the multidisciplinary approach: from reception ward physician and anesthesiologist to cardiologist, endocrinologist and neuropathologist. Moreover, the individual approach to the patient is provided, considering all above-mentioned risk factors. The advantages of this model for a doctor are distribution of decision making between trauma surgeon and other specialists by means of accept of the uniform decision of the concilium. Moreover, we convinced that qualitative preparation to surgery is initiated from the admission ward physician who must render qualified medical care, as well as collect anamnesis data for analysis.

As the conclusion, one should note the value of this method as a simple and non-expensive tool for estimation of the risk for patients and physicians, especially in conditions of developing countries. All future studies with big sample size and high amount of risk stratifications are necessary for improvement and more precise prediction of risks of possible postsurgical complications.

Information on financing and conflict of interests.

The study was conducted without sponsorship. The authors declare the absence of any clear and potential conflicts of interests relating to publication of this article.