Calculation and application of a safe range of load on the limb in patients after osteosynthesis of the femoral neck

Abstract

Background

Fractures of the femoral neck occupy a leading place in the total injury rate in the Russian Federation. Despite significant advances in the field of osteosynthesis of femoral neck fractures, there is still a high percentage of unsatisfactory treatment outcomes, including the cases when functional load is applied in the early activation of patients. Therefore, it is very important to find ways to dose the load on the operated limb in the postoperative period in patients with fractures of the femoral neck. The aim of the study is to demonstrate the successful experience of calculating and applying a safe range of load on the limb in patients after osteosynthesis of the femoral neck and substantiate its effectiveness using a universal personalized method of evaluating the results of treatment.

Methods

The study involved 80 patients with fractures of the femoral neck, who had undergone osteosynthesis with various metal structures. A safe range of load on the limb was applied using a method determined by us. The postoperative period results of the selected patients, who formed a comparison group and a study group, were then analyzed using a universal method of personalized evaluation of treatment results. A prospective study was applied.

Results

It was shown that in the study group of 40 patients, using the method developed by us for dosing the load on the limb, 12 months after surgery, 20.5% more excellent and good treatment results were obtained than in the comparison group.

Conclusions

Patients can have a better postoperative outcome owing to the possibility of determining the optimal range of load on the operated limb, which makes it possible to draw up an individual plan for dosing the load from the first day of the postoperative period to the onset of consolidation.

1. Introduction

Fractures of the femoral neck occupy a leading place in the total injury rate in the Russian Federation. Despite significant advances in the field of osteosynthesis of femoral neck fractures, the number of unsatisfactory treatment outcomes for this injury remains high.^1,2 Therefore, the treatment and rehabilitation of patients with hip joint fractures is an urgent problem in traumatology and orthopedics.^3,4

The hip joint is one of the most important elements of the human musculoskeletal system, enabling people to move in space. That is why damage in the area of the hip joint, especially with hip fractures, leads to a decrease in the quality of human life due to the occurrence of contractures, ineffective consolidation, deformities and a number of other clinically important problems, which is most often associated with errors in the management of the postoperative period in such patients, including incorrect dosing of the load.⁵ Due to the peculiarities of the blood supply to the femoral neck, the only effective method of treatment is surgery. Most often it is osteosynthesis.⁶ In modern trauma practice, the following methods of osteosynthesis of hip fractures are used: fascicular osteosynthesis with a bundle of spokes, osteosynthesis with AO compression screws, the use of a dynamic hip screw (DHS) and more modern constructions: Targon FN, PFN, Gamma-nail.7, 8, 9, 10, 11 7, 8, 9, 10, 11However, despite the variety of methods, the number of unsatisfactory outcomes of osteosynthesis remains high, especially while using the functional load during early activation of patients (Kolesnikov Yu.P., 1996, Lirtsman V.M., 1997, etc.).

One of the main ways for solving the problem of unsatisfactory outcomes of osteosynthesis during the postoperative period in patients with hip fractures is early activation with an adequate load on the operated limb. Despite the importance of the postoperative recovery period, there is still no single way to determine the optimal allowable load on the limb, which would be selected individually. The existing protocols for the management of postoperative patients with hip fractures do not take into account such parameters as different periods of consolidation of bone fragments depending on the type of fracture in patients of different age groups, the patient's body weight, the type of metal fixator, the postoperative day for which it is necessary to calculate the load.¹²

The purpose of this original study is to demonstrate the successful experience of the calculation developed by us and application of a safe range of load on the limb in patients after osteosynthesis of the femoral neck and substantiation of its effectiveness using a universal personalized method of evaluating the results of treatment.

2. Materials and methods

The material for the study was data obtained from medical records and the regional medical information system (RMIS), the medical examination results of 100 patients operated for hip fracture with the use of metal structures (PFN, TFN, GN, DHS, screws, spokes) during the period from February 2020 to April 2021, within the first two weeks from the date of admission to the hospital. During the selection of patients for the study, 20 people were excluded: 19 people did not meet the inclusion criteria (the study did not include patients who suffered a hip fracture as a result of an accident, industrial and criminal injury, pathological and chronic fractures, cases of combined polytrauma were excluded as well as surgery delayed more than 2 weeks from the date of fracture) and one patient refused to participate in the study (see Fig. 1).

Fig. 1.

Steps followed in the selection of patients for the study and comparison groups.

A prospective study was applied. The selection of patients into groups was carried out by random distribution, taking into account the inclusion and exclusion criteria.

We divided the 80 patients included in the study into two equal groups of 40 people each: comparison group and study group, comparable with each other in terms of sex and age. The average age of patients was 71.5, while the maximum age was 93, and the minimum was 50. The study group, consisting of 40 people, included some patients who were treated in the postoperative period using the method developed by us for calculating the optimal range of loads on the limb. In the comparison group, this method was not used, and the selection of the load on the limb was carried out according to the standard loading scheme, corresponding to the averaged indicators and the results of control radiographs.

The postoperative period results of the selected patients who made up the comparison group and the study group were analyzed using a universal method of personalized assessment of treatment results proposed in 2017 by Garkavi D., Garkavi A., Lychagin A.¹³ Evaluation of the results according to the method was carried out using questionnaires, the first of which was applied in the preoperative period, and the second one - 12 months after the operation.

In the preoperative period, all the patients completed a questionnaire scale, which is a universal way of personalized assessment of treatment results. The main attention of patients in the questionnaire is paid to those indicators that they would like to see at the end of treatment and which would satisfy them. Each of such indicators is called the desired result (DR). By the end of the observation (12 months after the operation), the patients of both groups filled out the same questionnaire again, describing their current health condition after treatment. Each of such indicators is called the achieved result (AR). Next, the final result (FR) is determined by the formula: FR = AR/DR•100%. If FR ≥ 100%, then the patient's expectations were met. In our study, we used the following interpretation of the results: FR >100% – excellent; 90%< FR ≤ 100% – good; 80%< FR ≤ 90% – satisfactory; FR ≤ 80% – unsatisfactory.¹³

We applied a method for determining the optimal range of loads on the limb after surgical treatment of the femoral neck fractures on the postoperative day when the patient is at the doctor’ s office while receiving recommendations regarding the load on the limb, which consists in determining the patient's body weight and the average time required for the healing of the considered fracture under, according to Kaplan's classification.¹⁴ This method is different from others, because we first calculated the initial values of maximum (x1) and minimum (x2) loads, limiting the range of loads for a particular postoperative day (t) according to the formula:

х1 = t × m/dmin, kg. х2 = t × m/dmax, kg., where m-is the patient's weight (mass), dmin – is a minimum duration of fracture healing, dmax - a maximum duration of fracture healing; then we determined the correction coefficients k1, k2, k3, reflecting the influence of the number of days that have passed from the moment of injury to the moment of surgery (preoperative day), the age of the patient and the type of metal structure for osteosynthesis on the load value, according to the correspondence table:

Parameter		Coefficient
		0,9	1	1,1	1,2
k1	Pre-surgery day	1	2–3	4–6	˃ 6
k2	Age	˂ 40	41–60	61–80	˃ 81
k3	Type of metal structure	PFN, TFN, GN	DHS, screws	Pins	–

Then we calculated the final values of the maximum (р1) and mimimum (р2) loads taking into account the coefficients k by formulas:

р1 = x1/k1 × k2 × k3 р2 = x2/k1 × k2 × k3;

After that, the range of loads on the limb after surgical treatment of a hip fracture was determined, which was limited by the obtained values of the final maximum (p1) and minimum (p2) loads. This method was filed for a patent of the Russian Federation №2021113924.

2.1. The results of the study

In both groups, 1 patient died before the end of the study. As we can see from the diagram, in the study group of 39 patients using our developed method of dosing the load on the limb, 12 months after the operation, 16 patients (41%) received an excellent result, 19 patients (48.7%) - a good final result, 2 patients (5.1%) – a satisfactory result, 2 patients (5.1%)- an unsatisfactory result. It should be noted that 2 patients with an unsatisfactory result had no consolidation of the fracture. In the comparison group, 10 patients (25.6%) achieved an excellent result, 17 patients (43.6%) – a good result, 9 patients (23.1%) – a satisfactory result and 3 (7.7%) patients – an unsatisfactory result. Thus, there are statistically significant differences in the number of satisfactory treatment results in the groups. So in the study group, a satisfactory result was observed 18% less often (Х2 = 5,186, p = 0,023). The number of good and excellent results was 20.5% higher in the study group (Х2 = 5,032, p = 0,025), which indicates higher treatment results of the patients in this group and a lower risk of postoperative complications. There were no statistically significant differences in the number of unsatisfactory results in both groups (see Fig. 2).

Fig. 2.

Results from study and comparison groups categorised by excellent, good, satisfactory, and unsatisfactory results.

3. Discussion of the results

The quality of medical care plays an important role in the treatment of patients with the femoral neck fractures of different ages, including the elderly and senile ages.^15,16 A correctly designed program of rehabilitation treatment is of decisive importance in determining the surgical outcome.^17,18 One of the main directions for solving the problem of unsatisfactory outcomes of the postoperative period is the early active use of a dosed load on the operated limb, provided that the bone fragments and metal structures are stable.¹⁹ However, the issues of adequate selection of the optimal dosage load and the timing of its start in the postoperative period for each specific case of hip fracture treatment still remain open and require additional research and discussion. Considering that the use of a generalized plan of postoperative management in patients with hip fractures can lead to inadequate stress and complications, it is necessary to form and use only an individual approach.^20,21 We proposed and tested a method for determining the optimal range of loads on the limb after surgical treatment of the femoral neck fractures on a particular postoperative day, which consists in determining the average time for healing of the fracture type under consideration, according to Kaplan's classification, as well as taking into account the patient's body weight.

After osteosynthesis using one of the metal structures (PFN,TFN, GN, DHS, screws, wires), the patients were transported to the intensive care and resuscitation ward, where the control and maintenance of vital body functions were carried out, and the primary set of therapeutic exercices was prescribed –breathing exercices-to prevent congestive complications of the pulmonary system. After stabilization of the condition, after 24–72 h, the patients were transferred to the ward of the trauma hospital, where they continued antibiotic and anticoagulant therapy, administration of non-narcotic painkillers on demand with the use of antacids and gastroprotective drugs, daily dressing of the postoperative wound and elastic bandaging of the lower extremities. After discharge from the hospital, the patient visited a traumatologist every month until recovery. With the help of these formulas, which from the basis of the method developed by us, a safe load range was calculated for each patient at each visit to the doctor. Thus, at each visit to the doctor, the safe load range changed depending on the time elapsed since the operation. The patient measured the calculated load independently using floor scales by pressing on the scales with the injured limb to the desired weight range, the patient memorized the intensity of pressure and then applied this load until next doctor appointment.

We recommend to use our proposed method for calculating the load on the limb after osteosynthesis to provide recommendations to the patient upon discharge from the hospital.

It is advisable for each patient who has undergone osteosynthesis of the femoral neck to calculate the safe load on the limb in the postoperative period at each visit to the doctor.

3.1. Limitations

The limitations, the exclusion criteria, met during this study are the following:

• -patients with pathological fractures,
• -cases of combined and associated injuries, for example, resulting from an accident, falling from a great height
• -the presence of severe somatic pathologies and chronic diseases in the stage of decompensation, mental disorders
• -age less than 18 years
• -the presence of persistent deformity, amputation of any segment and gross anatomical defects of a collateral healthy or injured lower limb
• -violation of static-dynamic function due to neurological diseases
• -chronic heart failure, false joint, gross deformity of the damaged or collateral hip joint (for example, deforming coxarthrosis stage 3–4)
• -refusal of the patient to participate in the clinical trial.

Based on our findings, we can conclude that the use of the method developed by us allows us to achieve better outcomes of surgical intervention for hip fractures. This is due to the possibility of determining the optimal range of load on the operated limb, which makes it possible to draw up an individual plan for dosing the load from the first day of the postoperative period to the onset of consolidation. Practical application of the method developed by us can help to avoid complications associated with excessive load on the operated limb (fracture or migration of metal structures, increased diastasis between fragments, etc.) or with its insufficient use, which leads to post-traumatic arthrosis, the development of joint contractures and muscle atrophy.

4. Conclusion

In the course of this study, we managed to demonstrate our successful experience in calculating and applying a safe range of load on a limb in patients after osteosynthesis of the femoral neck and substantiate its effectiveness using a universal personalized method of evaluating the results of treatment. Based on our data, we can conclude that the use of the method developed by us allows us to achieve better outcomes of surgical intervention for hip fractures. This is due to the possibility of determining the optimal range of load on the operated limb, which makes it possible to draw up an individual plan for dosing the load from the first day of the postoperative period to the onset of consolidation. Practical application of the method developed by us can help to avoid complications associated with excessive load on the operated limb (fracture or migration of metal structures, increased diastasis between fragments, etc.) or with its insufficient use, which leads to post-traumatic arthrosis, the development of joint contractures and muscle atrophy.

Institutional ethical committee approval (for all human studies)

The local ethics committee of Kotovsk City Clinical Hospital, Russian Federation has approved this study. All the patients signed voluntary informed consent to participate in the study. The study met the requirements of the Declaration of Helsinki, the International Conference on Harmonization (ICH), the Standards of Good Clinical Practice (GCP), the Federal Law "On the Basics of Health Protection of Citizens in the Russian Federation" № 323-FL dated 21 November 2011.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Declarations of interest

None.

CRediT authorship contribution statement

Oleg Nikolaevich Yamshchikov: Supervision. Sergey Alexandrovich Emelyanov: Formal analysis, Investigation, Resources, Writing – original draft. Sergey Alexeyevich Mordovin: Formal analysis, Investigation, Resources, Writing – original draft. Ekaterina Aleksandrovna Kolobova: Formal analysis, Investigation, Resources, Writing – original draft. Pavel Mikhailovich Teplyakov: Writing – review & editing. Mahulome Anne-Marie Dossou: Writing – review & editing.

Declaration of competing interest

None. The authors declare that there is no conflict of interest.