Effect of Blood Flow Restriction Training in Rehabilitation of Posterolateral Corner Reconstruction of Knee: A Case Study

Introduction

A knee is a sophisticated modified hinge joint having the greatest range of motion in flexion and extension along the sagittal plane, as well as varus and valgus rotation along the frontal plane. It also enables medial rotation at the end of knee flexion and lateral rotation at the end of knee extension in the transverse plane. During a range of loading scenarios, the knee maintains stability and control. Knee joint instability affects athletes and nonathletes, young and elderly adults, and those aged over 65 years which may have a serious effect with a higher risk of falls and a lengthy recuperation time.¹

The historical occurrence of posterolateral knee injuries has both been under- and over-reported, with a stated incidence of 4% to 7%. The overall prevalence of posterolateral knee injuries among all knee ligament injuries is 16%.²

The capsular and non-capsular components that serve as static and dynamic stabilizers support the posterolateral corner of the knee. The posterolateral corner structures contribute to the prevention of excessive external rotation, varus angulation, and posterior translation of the tibia relative to the femur.³ Posterior cruciate ligament injuries are commonly found in conjunction with posterolateral corner injuries.⁴ Posterolateral corner injury is a complicated and challenging entity in clinical practice, both in terms of diagnosis and therapy. The objective of this case study was to identify the functional outcomes following blood flow restriction training in the rehabilitation of posterolateral corner injuries of knee joint.

Case Description

A 26 year old male, residing at Kaikamba, Dakshina Kannada, Karnataka, visited outpatient department of Alva’s College of Physiotherapy and Research Centre at Moodbidri, Dakshina Kannada, Karnataka, on 28^th October 2022 with a complaint of pain and weakness in the right knee while climbing stairs and during walking activities. He was an accountant by profession working at a private firm. He visited the outpatient Physiotherapy clinic with an intention to get relief from the discomfort he experiences in his knee joint during activities of daily life.

During the clinical interview, he revealed that he sustained a road traffic accident involving skid and fall from his two-wheeler, on 1^st January 2022 at around 2:30 am near Mangalore highway. From the location of the road traffic accident, he was shifted to a nearby hospital for first aid and further management. As per the available documents, there were no history of unconscious or ENT bleeding or symptoms of substance abuse at the time of road traffic accident. The magnetic resonance imaging (MRI) of his right knee joint revealed Grade III anterior cruciate ligament tear, Grade III tear of posterior horn of the medial meniscus, Grade I sprain of medial collateral ligament, depressed lateral tibial plateau fracture with marrow edema in the postero-lateral condyle of tibia and marrow edema in the head of the fibula with edematous changes in the popliteus muscle and tendon- in keeping with posterolateral corner injury.

Initially, the patient preferred conservative rehabilitation for which his right knee was immobilized with a knee brace, and was taught to perform gentle isometrics for muscles around knee and hip with cryotherapy to reduce edema. He was also prescribed with medications to manage pain and the inflammation around knee joint. Following two months of conservative management, the orthopedician identified instability of knee joint on clinical examination and hence suggested the patient for arthroscopic anterior cruciate ligament reconstruction with hamstring graft, posterior cruciate ligament reconstruction with peroneal graft on 9^th March 2022. Postoperative period was uneventful and the patient was performing the exercises as taught by the physiotherapist from the hospital.

Though the patient could walk and perform daily activities, he continued to experience minimal pain, discomfort and difficulties in knee joint, especially during activities requiring knee flexion beyond 90°. Therefore, he visited our outpatient clinic at Alva’s College of Physiotherapy and Rehabilitation Centre. On examination, it was observed that he had ectomorphic body built, limping gait on right lower limb, with right quadriceps and hamstring muscle atrophy. Swelling was observed over the anterior and posterior aspects of knee joint. Arthroscopic scars, well healed, non-adherent, 5 cm in length were located on inferio-medial aspect of the knee joint and another scar was present just above the lateral malleoli of right leg. There was no postural deviation. Observational gait analysis revealed antalgic pattern of gait. On palpation, there was warmth present around the knee joint and grade I tenderness present over the lateral aspect of the right knee joint. On examination, there was crepitus in right knee joint during knee flexion - extension activities beyond 90° and while climbing stairs. Manual muscle testing demonstrated weakness, grade 4, in right quadriceps, hamstrings and dorsiflexors. The thigh circumference on the right side was 44 cm compared to 50 cm in the left. Similarly, calf muscle circumference on the right side was 32 cm and on the left side was 34 cm, indicating weakness of thigh and calf muscles. Gait analysis indicated that stride length on left side was asymmetrical compared to right side.

Lower extremity functional scale is a valid and reliable outcome measure to evaluate lower extremity function.⁵ It consists of 20 questions with increasing physical demands with a score of 0 to 4 for each question. A total of 80 points can be scored by an individual indicating maximum lower extremity function. Our patient reported a lower extremity functional scale score of 42.5 out of 80 as baseline score before blood flow restriction training. Blood flow restriction training was provided for fifteen sessions following which the patient demonstrated a lower extremity functional scale score of 62 out of 80.

Blood flow restriction training procedure

Blood flow restriction training helps to improve muscle weakness and atrophy without loading the healing tissues. In this study, patient underwent blood flow restriction training, three sessions per week, for a total of 15 sessions in five weeks. Blood flow restriction training was performed under the supervision of a senior physiotherapist. The blood flow restriction training cuff pressure was determined based on percentage of systolic blood pressure above 130%. To determine the exercise intensity, one repetition maximum of hamstring & quadriceps was calculated.

• Hamstring curls (Figure 1)
• Knee extension
• Wall squats

In addition to the exercises mentioned in Table 1, patient was taught to perform the other strengthening exercises, balance, weight bearing exercises and gait training. According to Hernandez et al., (2013) four sets of repetitions in the order of 30-15-15-15 was considered. Between each set, a rest period of one minute was provided. Concentric contraction of hamstrings, quadriceps and closed chain mini squats were performed. The outcome evaluation of lower extremity functional scale performed on 15^th November 2022 demonstrated a score of 60 out of 80, indicating improvement in lower extremity functions in terms of strength following blood flow restriction training program.

Discussion

The objective of this case study was to evaluate the effect of blood flow restriction training in the rehabilitation of posterolateral corner reconstruction patients with chronic residual muscular impairments. The results suggested that blood flow restriction training could be effective in addition to the routine rehabilitation program in individuals with posterolateral corner reconstruction.

Persistent and residual weakness of quadriceps and hamstring is demonstrated following arthroscopic surgeries, preventing the individuals from returning to active lifestyle or athletic activities. To optimize knee joint loading, muscle strengthening is recommended.⁵ To achieve hypertrophy of muscles in general population, the resistance training intensity ranging from 60% to 70% of maximum one repetition is recommended. In postoperative individuals with weak muscles and associated deficits, it is challenging to train at these intensity ranges. Partial vascular occlusion using extremity tourniquet in blood flow restriction training program has the potential to hypertrophy the muscles at 30% of one repetition maximum, postoperatively. Individuals with postoperative muscular deficits tolerate blood flow restriction training program effectively than the routine resistance training program.

The results in the present case study are similar to the findings of Noyes et al. (2021),⁶ who concluded that blood flow restriction training is effective in improving peak torque strength of quadriceps and hamstring in post arthroscopic patients with residual muscle strength deficits.

Contrary to this, Curran et al. (2020),⁷ concluded that adding metabolic stress to the muscles of individuals undergoing anterior cruciate ligament reconstruction with blood flow restriction training did not result in improvement in muscle strength. The contributing factor for lack of inefficiency of blood flow restriction training in this study could be due to closed chain exercises which failed to isolate the weaker muscles.

Blood flow restriction training could be effective in improving lower extremity muscle functions such as thigh circumference and quadriceps-hamstring strength in individuals with post arthroscopic residual muscular impairments in posterolateral reconstruction procedures.

Conflict of interest

None

Acknowledgment

We thank all the staffs of Alva's College of Physiotherapy and Research Centre, Alva's Health Center and The Management Trustee and The Chairman of Alva's Education foundation, Moodubidire, Dakshina Kannada for their support in this research work. Also we extend our sincere thanks to Rajiv Gandhi University of Health Sciences, Advanced Research director and the team for their efforts in reviewing, evaluating and improving this research article.