In vivo loading on the hip joint in patients with total hip replacement performing gymnastics and aerobics exercises

Henryk Haffer,Srdan Popovic,Franziska Martin,Philipp Damm,Sebastian Hardt,Tobias Winkler

doi:10.1038/s41598-021-92788-7

Abstract

A further increase in the number of total hip arthroplasty (THA) is predicted, in particular the number of young THA patients has raised and with it their demands. There is no standardized evidence-based rehabilitation program and no reliable guidelines for sports activities after THA. Stretching and strengthening gymnastics are routinely performed in rehabilitation and aerobics as a sport after THA. The aim of the investigation was to determine the in vivo force and moments acting on the hip prosthesis during gymnastics and aerobic exercises to provide a source for evidence-based recommendations. Hip joint loads were measured in six patients with instrumented hip implants. The resulting force FRes, bending moment MBend at the neck and torsional moment MTors at the stem were examined during seven strengthening (with two different resistance bands) and four stretching gymnastic exercises and seven aerobic exercises with and without an aerobic step board compared to the loads during the reference activity walking. The stretching and strengthening gymnastics exercises and the aerobic exercises with and without a board demonstrated in their median peak force and moments mostly lower or similar values compared to walking. Significantly increased loads were recorded for the flexor stretching exercise in monopod stand (Fres and MBend), the strengthening abduction exercise on the chair (MTors) and the strengthening flexion exercise with the stronger resistance band (MTors). We also found a significant increase in median peak values in aerobic exercises with a board for the "Basic Step" (ipsilateral started Fres and MTors; contralateral started MTors), "Kickstep ipsilateral started" (Fres and MTors) and "Over the Top contralateral started" (Fres). The in vivo loads in THA patients during frequently performed stretching, strengthening and aerobic exercises were demonstrated for the first time. It was proved that stretching gymnastic exercises are safe in terms of resulting force, bending and torque moments for THA patients, although an external assistance for stabilization may be considered. Strengthening gymnastics exercises are reliable in terms of Fres, MBend and MTors, but, based on our data, we recommend to adhere to the communicated specific postoperative restrictions and select the resistance bands with lower tension. Aerobic exercises without an aerobic board can be considered as reliable activity in terms of force and moments for THA patients. Aerobic exercises with a board are not recommended for the early postoperative period and in our opinion need to be adapted to the individual muscular and coordinative resources.

Highlights

A further increase in the number of total hip arthroplasty (THA) is predicted, in particular the number of young THA patients has raised and with it their demands
The authors’ survey questionnaire did not specify the time, type or intensity of training required[15]. It is unknown how the hip joint is loaded effective in vivo during gymnastics and aerobic exercises
The investigation aims to evaluate the in vivo loads occurring at the femur head, neck and stem (Fig. 1) during selected gymnastics and aerobic exercises in patients with instrumented hip implants

Summary

Introduction

A further increase in the number of total hip arthroplasty (THA) is predicted, in particular the number of young THA patients has raised and with it their demands. The in vivo loads in THA patients during frequently performed stretching, strengthening and aerobic exercises were demonstrated for the first time. The authors’ survey questionnaire did not specify the time, type or intensity of training required[15] It is unknown how the hip joint is loaded effective in vivo during gymnastics and aerobic exercises. Moderate physical activity is considered to improve implant longevity by stimulating bone metabolism leading to enhanced osteointegration and muscular stabilization of the joint with presumably reduced risk of dislocation[19,20] It is being discussed whether physical activity may increase wear and aseptic loosening by inducing mechanical strain, torsion forces may affect the stability of the s tem[20,21,22,23]. No significant literature reported on early activity after THA and increased rates of periprosthetic fractures or THA instability[12]

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Conclusion