Silvia Dullien

Leg length and offset differences above 5 mm after total hip arthroplasty are associated with altered gait kinematics

We aimed to investigate the relationship between postoperative leg length/offset (LL/OS) reconstruction and gait performance after total hip arthroplasty (THA). In the course of a prospective randomized controlled trial, 60 patients with unilateral hip arthrosis received cementless THA through a minimally-invasive anterolateral surgical approach. One year post-operatively, LL and global OS restoration were analyzed and compared to the contralateral hip on AP pelvic radiographs. The combined postoperative limb length/OS reconstruction of the operated hip was categorized as restored (within 5mm) or non-restored (more than 5mm reduction or more than 5mm increment). The acetabular component inclination, anteversion and femoral component anteversion were evaluated using CT scans of the pelvis and the femur. 3D gait analysis of the lower extremity and patient related outcome measures (HHS, HOOS, EQ-5D) were obtained pre-operatively, six months and twelve months post-operatively by an observer blinded to radiographic results. Component position of cup and stem was comparable between the restored and non-restored group. Combined LL and OS restoration within 5mm resulted in higher Froude number (p<0.001), normalized walking speed (p<0.001) and hip range-of-motion (ROM) (p=0.004) during gait twelve months postoperatively, whereas gait symmetry was comparable regardless of LL and OS reconstruction at both examinations. Clinical scores did not show any relevant association between the accuracy of LL or OS reconstruction and gait six/twelve months after THA. In summary, postoperative LL/OS discrepancies larger than 5mm relate to unphysiological gait kinematics within the first year after THA. DRKS00000739, German Clinical Trials Register.

Measuring functional outcome after total hip replacement with subject-specific hip joint loading.

Total hip replacement is an often-performed orthopedic surgical procedure; the amount of procedures undertaken will increase since our life expectancy is growing. In order to optimize function, hip biomechanics should be restored to as near normal as possible. The goal of this pilot study was to determine whether or not it is feasible to compute the vectorial hip reaction force pathways on the head of the prosthesis and the force angles relative to the cup of the prosthesis that occur during gait in total hip replacement patients, serving as an objective measurement of the functional outcome following hip replacement. A three-dimensional gait analysis, measuring ground reaction forces and kinematics, was performed. The data retrieved from the gait analysis was used as the input for the musculoskeletal model to compute vectorial joint reaction forces for data processing. To evaluate the position and orientation of the joint reaction forces, the force path, as well as the force angles for the operated and non-operated joint, has been calculated during the stance phase of the specific leg. The force path for subject 2 on the non-operated side is only located in the posterior-lateral quarter, as is the force path for subject 1. In contrast to this subject, the force path for subject 2 at the operated hip joint can be found only within the anterior quarter of the head of the implant, where it is nearly equally distributed in the medio-lateral half of the prosthesis head. The force-inclination angles on the cup of subject 1, with respect to the plane of the socket face, indicates that the force vector is mainly positioned in the same quadrant when compared with subject 2 (in a cup-fixed coordinate system). The force-anteversion angle behaves similarly to the force-inclination angle, even when the effects are not as pronounced. The proposed methods in this article are aiming to define two functional outcomes of total hip replacement that are related to wear and rim loading. It is accepted that wear is not only a function of time, but a function of use. Owing to the methods listed in this article, we are able to determine a) the applied force and b) the sliding distance (force pathway) in a subject-specific manner. The computed hip-reaction force angles and the distance to the rim cup are a measurement for cup or rim loading, and occurs in the so-called safe-zones. This method may well give us insight into the biomechanical situation during gait, after receiving total hip replacement, that we need to fully understand the mechanisms acting on a hip joint and to prove a possible increase of functional outcome after receiving total hip replacement.

Gait Analysis after Tibialis Anterior Tendon Rupture Repair Using Z-Plasty

Other than limited reports regarding surgical outcomes, little information is available regarding whether Z-plasty of the tibialis anterior results in normal gait kinematics. We included 5 patients with spontaneous ruptures in the present retrospective study. The mean interval between rupture and operative treatment was 2.6 ± 2.6 months (standard deviation). The mean age of the patients was 63 (range 40 to 80) years. All patients were treated operatively with Z-plasty. Gait analysis was used to study the outcome, comparing the operated and nonoperated limbs. The patients were tested after a mean follow-up of 22 (range 12 to 33) months. No repeat ruptures were noted. Plantarflexion was significantly diminished during the preswing phase and initial swing phase in the operated limbs compared with the uninjured limbs. Plantarflexion was significantly increased during the terminal swing phase on the operated side. Knee flexion was nearly symmetrical. No significant differences regarding the temporospatial parameters were noted. We recommend Z-plasty for ruptures of the tibialis anterior tendon as a safe and effective procedure. However, this technique does not fully restore a physiologic gait pattern.

Off-loading strategies in diabetic foot syndrome–evaluation of different devices

IntroductionDiabetic foot syndrome is one of the most dreaded complications in diabetes mellitus. The purpose of this study was to assess the value of different offloading devices compared to walking in barefoot condition and in normal shoes both in healthy subjects and in patients with diabetes and neuropathy.MethodsTwenty patients with diabetes and polyneuropathy and ten healthy probands were included. Pedobarographic examination was performed in barefoot condition, with sneakers, postoperative shoes, Aircast® Diabetic Pneumatic Walker™ and VACO®diaped. In the diabetic group, a total contact cast was additionally tested.ResultsThe most effective reduction of force was achieved by TCC (75%) and VACOdiaped (64.3%) with the VACO®diaped resulting in the most homogeneous distribution of forces all over the foot.Discussion/ConclusionA customized device like the TCC is still the most proven offloading device. However, a removable cast walker being based on vacuum pads and a cushioning sole, provides better results concerning force distribution.

Cluster-randomized, controlled evaluation of a teacher led multi factorial school based back education program for 10 to 12-year old children

BackgroundThe aim of this cluster-randomised, controlled study was to examine whether a teacher-led multifactorial back education programme could improve back pain in pupils, motor skills, back behaviour, and back knowledge over a 10-month period.MethodsThere were 176 children from two schools, who were cluster-randomised into intervention and control groups. The intervention programme consisted of 3 parts: 1) knowledge improvement, 2) posture awareness training, and 3) reducing imbalance of core muscles through mandatory back and abdominal muscle exercises at the beginning of each physical education lesson. Outcome measures included a clinical orthopaedic examination, a health questionnaire, a motor test, a back-behaviour trial, and a knowledge test.ResultsClinical examination showed a reduction of orthopaedic abnormalities in both groups, from 90.5 to 42%, with a posture test showing an improvement in both groups at the post-test. However, the rate of children reporting back pain at least once a month could not be reduced below 30%. Long lasting physical activity, carrying heavy schoolbags, and long periods of sitting were the top three causes for back pain. Push-up number and balancing skills improved significantly in both groups from pre- to post-test. In the water crate carrying task and knowledge test, only the intervention group (IG) showed a statistically significant improvement from pre- to post-test.ConclusionsThe results show that back pain rate could not be decreased. However, back care knowledge and parts of back-friendly behaviour could be significantly improved. On the other hand, the problem of prolonged sitting and using heavy schoolbags persists.Trial registrationDeutsches Register Klinische Studien DRKS00013794; Date of Registration: 15.1.2018; Retrospectively registered.

Postural Stability after Unicondylar Knee Arthroplasty and Patient-Specific Interpositional Knee Spacer

Purpose and Hypothesis. Knee osteoarthritis results, inter alia, in decreased postural stability. After arthroplasty, postural stability recovers, but it is unclear whether this can be ascribed to a reduction of pain or to the preserving of receptor-rich intraarticular soft tissue and natural knee kinematics. The objective of this study was to evaluate whether an unicondylar knee arthroplasty provides better results regarding postural stability or a patient-specific knee spacer. Methods. In this comparative study, we assessed functional results and postural stability 16 months after 20 unicondylar knee arthroplasties (group A) and 20 patient-specific interpositional knee device implantations (group B). Patients were evaluated using the KSS and WOMAC score. Postural stability was analysed during single leg stance on a force platform (Biodex Balance System). Results. Concerning postural stability, range of motion (ROM), and KSS 16 months after the procedure, there were no significant differences between both groups. Conclusion. Successful treatment of knee osteoarthritis restores postural stability to the level of the contralateral side, regardless of the implant device.