Clinical and Functional Outcomes at Least 2 Years After Hamstring Muscle Repair

University Hospital, Basel, Switzerland13 enrolled

Overview

This study is to evaluate functional outcomes of a new, intraoperative lateral positioning of the anchors on the tuber ischiadicum, in comparison to regular anatomical anchoring direct on top of the tuber ischiadicumafter hamstring muscle repair. This study is to quantify at least 2 years postoperative functional, biomechanical and clinical outcomes including side-to-side differences in muscle strength, unipedal balance, gait, jumping and squatting function, muscle activity, in patients treated by hamstring muscle repair.

The design of this pilot study is a descriptive cross-sectional single centre analysis involving all patients previously treated with hamstring repair. All of these patients will be asked to participate in clinical and detailed functional analysis at least 2 years after surgery. Specifically, biomechanical and functional data including isokinetic muscle strength, clinical scores, ROM, joint kinematics and kinetics during walking, running, squatting and single leg jumps, muscle activity and single leg balance ability in the affected and contralateral leg will be collected. These parameters will be compared between legs and correlated with clinical scores.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Hamstring Muscle Repair Hamstring Rupture

Interventions

assessment of muscle strengthOTHER

Muscle strength will be measured bilaterally using a dynamometer (Biodex System 4 Pro: Biodex Medical Systems, Shirley, NY, USA). For the knee, maximum isokinetic flexion and extension torques will be collected between full extension and full flexion at a movement speed of 60°/s (5 repetitions) and 240°/s (15 repetitions). Maximum joint torques in each movement direction will be recorded for each joint and normalized to body weight.

assessment of gaitOTHER

Instrumented gait analysis on a treadmill with an embedded plantar pressure plate (h/p/cosmos, Zebris FDM-T, Isny, Germany; 7168 sensors; area, 1.5 \* 0.5 m; range, 1-120 N/cm2; precision, 1-120 N/cm2 ± 5%; sampling rate, 120 Hz) and on an overground walkway with two embedded force plates (Kistler force plate 9260AA6, Kistler AG, Winterthur, Switzerland; sampling rate 2400 Hz). Simultaneously with the plantar pressure or force data, kinematic and electromyographic (EMG) data will be collected. Participants will then walk for 1 minute at their preferred walking speed (0% slope and at 15% slope) and at 1.2 m/s (0% slope). For all conditions, kinematic, EMG and pressure data will be recorded for 1 minute. Subsequently, the treadmill speed will be increased to preferred running speed and 2.3 m/s (0% slope), and data for 1 minute running will be recorded. Subjects will then complete overground walking and running trials on the walkway with embedded force plates.

assessment of squatting and single leg hopsOTHER

Participants perform three jumps on a force plate. Maximum jump length, Maximum flexion and extension angles and joint moments will be identified. Subsequently, participants perform three squats onto two force plates (one per foot). On- and off times will be computed for each muscle and condition.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * At least 2 years since hamstring muscle repair Exclusion Criteria: * Revision surgery within 6 months before testing on the ipsilateral knee and hip * BMI \> 35 kg/m2 * Previous injury and surgical procedures of the contralateral knee and hip within the last year * Neuromuscular disorders affecting lower limb movement * Additional pathologies that influence the mobility of the lower extremity * Inability to provide informed consent

Outcomes

Primary Outcomes

Isokinetic muscle strength

Isokinetic muscle strength deficit of the knee flexors and extensors in the injured leg compared to the contralateral leg, assessed by a dynamometer