Hip abductor strengthening post-TKR

Key Points

1. Study overview: The study investigates whether adding hip abductor strengthening exercises to rehabilitation improves outcomes post-total knee replacement (TKR).
2. Clinical implication: Findings suggest that additional hip abductor exercises do not provide significant benefits over standard rehabilitation.
3. Patient advice: Patients can expect similar recovery with or without specific hip strengthening exercises post-TKR.
4. Physiotherapy guidance: Physiotherapists should focus on standard rehabilitation protocols, as additional hip abductor exercises may not offer extra benefits.
5. Limitations: The study’s findings are limited to a specific population and may not be generalisable to all patients undergoing TKR.

How was the study conducted?

The study, titled “Incorporating hip abductor strengthening exercises into a rehabilitation program did not improve outcomes in people following total knee arthroplasty: a randomised trial,” aimed to evaluate the efficacy of adding hip abductor strengthening exercises to a standard rehabilitation program following total knee replacement (TKR). It was conducted as a randomised controlled trial with 105 participants who had undergone primary TKR for knee osteoarthritis. The study was carried out at a private rehabilitation hospital, with participants randomly assigned to either the experimental group or the control group​​.

How were the participants grouped?

Participants were divided into two groups:

1. Experimental Group: This group included 54 participants who received a standard rehabilitation program supplemented with additional hip abductor strengthening exercises.
2. Control Group: This group comprised 51 participants who received the same standard rehabilitation without the additional hip exercises​​.

How did they measure the success of the programme?

The success of the programme was measured using several primary and secondary outcome measures:

• Primary Outcomes: Knee Injury and Osteoarthritis Outcome Score (KOOS) and isometric hip abductor muscle strength.
• Secondary Outcomes: Stair climb test, 6-minute walk test, Timed Up and Go test, 40-m fast-paced walk test, 30-second chair stand test, step test, isometric quadriceps muscle strength, Lower Extremity Functional Scale (LEFS), and Short Form-12 (SF-12) questionnaires​​.

What were the interventions or treatment of each group?

• Experimental Group: Participants followed a standard rehabilitation program, including exercises targeting quadriceps, hamstring, and calf strength. In addition, they performed specific hip abductor strengthening exercises such as side-lying hip abduction and standing hip abduction with resistance bands.
• Control Group: Participants followed the same standard rehabilitation program without the specific hip strengthening exercises. Instead, they engaged in general functional exercises like sit-to-stand and marching​​.

What were the results of the study between each intervention or treatment group?

The study found no significant differences between the experimental and control groups in terms of primary or secondary outcomes. Both groups showed improvements in muscle strength, functional performance, and patient-reported outcomes, but the addition of hip abductor strengthening exercises did not result in significantly greater improvements. At 6 and 26 weeks, both groups had similar scores on the KOOS and other functional tests, indicating that targeted hip strengthening did not provide additional benefits​​.

What is concluded in the study?

The study concluded that incorporating hip abductor strengthening exercises into a standard rehabilitation program post-TKR does not significantly improve muscle strength, functional performance, or patient-reported outcomes compared to general functional exercises. The findings suggest that specific hip abductor exercises may not be necessary for optimal recovery following TKR​​.

In which group of patients would this be most useful for?

This information is particularly relevant for patients undergoing TKR who may have concerns about specific muscle weakness or functional deficits. The study’s results indicate that a standard rehabilitation program without additional hip abductor exercises is sufficient for most patients, making the findings applicable to a broad range of TKR patients​​.

What are the limitations of this study?

• Population Specificity: The study was conducted in a private rehabilitation hospital with privately insured patients, limiting the generalisability of the findings to the public sector or other healthcare settings.
• Homogeneity of Participants: The study included a relatively homogeneous group of patients, potentially limiting the applicability of the findings to more diverse populations.
• Intervention Fidelity: Although efforts were made to standardise the interventions, variations in therapist experience and patient adherence could have influenced the outcomes​​.

As a patient, how should you use this information?

Patients undergoing TKR can use this information to understand that a standard rehabilitation program without specific hip abductor strengthening exercises can still provide adequate recovery. The study suggests that additional exercises targeting the hip abductors may not be necessary, allowing patients to focus on other aspects of their rehabilitation​​.

How should this information improve your clinical reasoning or management of the patient post-TKR?

You should consider these findings when designing rehabilitation programs for TKR patients. The lack of additional benefits from specific hip abductor strengthening exercises suggests that focusing on a well-rounded standard rehabilitation program may be more efficient and equally effective. This approach allows for more tailored therapy based on individual patient needs rather than adding unnecessary exercises​​. However, though the study might not have shown it’s effectiveness in the managemenr of TKR patients, consider as well how the hip muscles might have weaken because of decreased weight-bearing over the operated side. 

The study supports the use of general functional exercises as part of a comprehensive rehabilitation program, making it suitable for a wide range of patients​​.

Conclusion

The study provides valuable insights into the management of rehabilitation post-TKR. It demonstrates that additional hip abductor strengthening exercises do not offer significant benefits over standard rehabilitation programs. Both patients and Physiotherapists should focus on a well-rounded approach that prioritises functional recovery and patient-reported outcomes. Evidence-informed practice does not rule out the use of hip abductor training. Be guided instead by your clinical reasoning as you care for each patient. 

If you’re unsure about whether you’re receiving sufficient care post-TKR, do contact us to find out more today! 

Ref:

Schache, M. B., McClelland, J. A., & Webster, K. E. (2019). Incorporating hip abductor strengthening exercises into a rehabilitation program did not improve outcomes in people following total knee arthroplasty: a randomised trial. Journal of Physiotherapy, 65(3), 136–143. https://doi.org/10.1016/j.jphys.2019.05.008

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