Objectives. The objective of this study was to quantify the relative movement between the articular surfaces in the tibiotalar and subtalar joints during normal walking in asymptomatic individuals. Methods. 3D movement data of the ankle joint complex were acquired from 18 subjects using a biplanar fluoroscopic system and 3D-to-2D registration of bone models obtained from CT images. Surface relative velocity vectors (SRVVs) of the articular surfaces of the tibiotalar and subtalar joints were calculated. The relative movement of the articulating surfaces was quantified as the mean relative speed (RS) and synchronization index (SI. ENT. ) of the SRVVs. Results. SI. ENT. and mean RS data showed that the tibiotalar joint exhibited translational movement throughout the stance, with a mean SI. ENT. of 0.54 (. sd. 0.21). The mean RS of the tibiotalar joint during the 0% to 20% post heel-strike phase was 36.0 mm/s (. sd. 14.2), which was higher than for the rest of the stance period. The subtalar joint had a mean SI. ENT. value of 0.43 (. sd. 0.21) during the stance phase and exhibited a greater degree of
Dual mobility hip arthroplasty utilizes a freely rotating polyethylene liner to protect against dislocation. As liner motion has not been confirmed in vivo, we investigated the liner kinematics in vivo using dynamic radiostereometry. 16 patients with Anatomical Dual Mobility acetabular components were included. Markers were implanted in the liners using a drill guide. Static RSA recordings and patient reported outcome measures were obtained at post-op and 1-year follow-up. Dynamic RSA recordings were obtained at 1-year follow-up during a passive hip movement: abduction/external rotation, adduction/internal rotation (modified FABER-FADIR), to end-range and at 45° hip flexion. Liner- and neck movements were described as anteversion, inclination and
Shortness of an extremity due to different causes is an issue that may adversely affect human life functional and psychologically. In this study, in the light of previous studies, it is aimed to develop a new expandable intramedullary system, providing lengthening in order to remove previous problems and complications and to annihilate leg length discrepancies at present and future without second surgical intervention as far as possibble by lenghtening the intramedullary nail. To this end, a new electromechanically activated intramedullary nail has been designed and generated. The intramedullary nail was designed to perform extremity lengthening electro-mechanically. The 3D design of the system is performed with computer software and the rapid and metal prototype of the system has been produced. The intramedullary nail system is comprised of three main units; Mechanical transmission unit, Electronic unit, Lengthening unit. The nail system is designed to function both mechanically and electronically complying with the requirement. This also provides an advantage that if any one (mechanic or electronic) fails, the lengthening process can continue with the other. Compression tests are applied in order to evaluate the strength of the system. The deformation values of the parts are recorded and stress values of each parts were calculated. The new system needs only 300N loading for mechanical lengthening. When 800N is considered as average human weight, the implant must withstand minumum 2400N load. Considering the safety conditions, we applied 4000N load on the new system. At 4000N, the whole system shows only 1.465 mm deformation which is less than the gap between the two bone parts. Also, when the system is implanted inside the bone, the loads are distributed proportionally between the bone and the implant. So, except for extraordinary conditions, the newly developed system is highly rigid and safe. In each applied method, lots of complications whether general or method-specific are seen. When the methods like Albizzia, ISKD and FITBONE avaliable and widely used today are examined separately, complications specific to these methods can be clearly observed [1–12]. Bliskunov Nail, Albizzia Nail and ISKD [13–18] have mechanical working principles and in these systems, lengthening process is obtained by
Introduction. The low-contact stress (LCS) knee prosthesis is a mobile-bearing design with modifications to the tibial component that allow for meniscal-bearing (MB) or rotating-platform (RP). The MB design had nonconstrained anteroposterior and
The Step Holter is a software and mobile application that can be used to easily study gait analysis. The application can be downloaded for free on the App Store and Google Play Store for iOS and Android devices. The software can detect with an easy calibration the three planes to detect the movement of the gait. Before proceeding with the calibration, the smartphone can be placed and fixed with a band or stowed into a long sock with its top edge at the height of the joint line, in the medial side of the tibia. The calibration consists in bending the knee about 20 to 30 degrees and then making a
Introduction. Achieving high flexion after total knee arthroplasty (TKA) is one of the most important clinical results, especially in eastern countries where the high flexion activities, such as kneeling and squatting, are part of the important lifestyle. Numerous studies have examined the kinematics after TKA. However, there are few numbers of studies which examined the kinematics during deep knee flexion activities. Therefore, in the present study, we report analysis of mobile-bearing TKA kinematics from extension to deep flexion kneeling using 2D-3D image matching technique. Materials and Methods. The subjects were 16 knees of 8 consecutive patients (all women, average age 75.9), who underwent primary mobile-bearing PS TKA (P.F.C. sigma RP-F: Depuy Orthopedics Inc., Warsaw, IN, USA) between February 2007 and May 2008. All cases were osteoarthritis with varus deformity. Postoperative radiographs were taken at the position of extension, half-squatting and deep flexion kneeling 3 month after the surgery, and the degrees of internal rotation of the tibial component was measured by 2D-3D image matching technique. Pre- and post-operative ROM was recorded. Then, we compared the absolute value and relative movement of tibial internal rotation between extension, half-squatting and deep flexion kneeling, and evaluated the correlation of the ROM and the internal rotation. Results. The mean preoperative ROM was from -12 to 118 degrees. After the surgery, ROM was from -2 to 123 degrees. Clinical scores of all cases were significantly improved after surgery. Internal rotation of tibial component was -6.8 to 9.7 (mean, 1.7) degrees at half-squatting position, and -7.2 to 13.6 (mean; 1.9) degrees at kneeling position. There was no correlation between maximum flexion angle and tibial rotation during flexion. There was significant negative correlation between tibial internal rotation angle in extension and tibial
Aims
The objective of this study was to compare simulated range of motion (ROM) for reverse total shoulder arthroplasty (rTSA) with and without adjustment for scapulothoracic orientation in a global reference system. We hypothesized that values for simulated ROM in preoperative planning software with and without adjustment for scapulothoracic orientation would be significantly different.
Methods
A statistical shape model of the entire humerus and scapula was fitted into ten shoulder CT scans randomly selected from 162 patients who underwent rTSA. Six shoulder surgeons independently planned a rTSA in each model using prototype development software with the ability to adjust for scapulothoracic orientation, the starting position of the humerus, as well as kinematic planes in a global reference system simulating previously described posture types A, B, and C. ROM with and without posture adjustment was calculated and compared in all movement planes.
Aims
Manual impaction, with a mallet and introducer, remains the standard method of installing cementless acetabular cups during total hip arthroplasty (THA). This study aims to quantify the accuracy and precision of manual impaction strikes during the seating of an acetabular component. This understanding aims to help improve impaction surgical techniques and inform the development of future technologies.
Methods
Posterior approach THAs were carried out on three cadavers by an expert orthopaedic surgeon. An instrumented mallet and introducer were used to insert cementless acetabular cups. The motion of the mallet, relative to the introducer, was analyzed for a total of 110 strikes split into low-, medium-, and high-effort strikes. Three parameters were extracted from these data: strike vector, strike offset, and mallet face alignment.
Aims
Despite limited clinical scientific backing, an additional trochanteric stabilizing plate (TSP) has been advocated when treating unstable trochanteric fractures with a sliding hip screw (SHS). We aimed to explore whether the TSP would result in less post operative fracture motion, compared to SHS alone.
Methods
Overall, 31 patients with AO/OTA 31-A2 trochanteric fractures were randomized to either a SHS alone or a SHS with an additional TSP. To compare postoperative fracture motion, radiostereometric analysis (RSA) was performed before and after weightbearing, and then at four, eight, 12, 26, and 52 weeks. With the “after weightbearing” images as baseline, we calculated translations and rotations, including shortening and medialization of the femoral shaft.
Introduction:. Shoulder balance after surgery is one main attribute of the cosmetic outcome. It has been difficult to assess on 2D images. The balance results from the interaction of rib cage, shoulder joint and scapular positions, spinal alignment and rotation, muscle size and co-ordination and pain interaction. Attempts have been made to predict shoulder balance from radiograph measurements. There is no consensus on this. Attempt:. To assess whether T1 tilt has any relation to final shoulder balance after surgery. Method:. Retrospective review of radiographs of adolescent idiopathic scoliosis patients from 2009 to 2012. 61 identified with average age of 17 and follow up of 24 months. T1 tilt is measured pre-op, immediately post-op and at the latest follow up. Radiographic shoulder balance based on soft tissue shadow is assessed at the same interval. The balance is based on eyeballed perception, which is what patients do normally. Results:. The average T1 tilt is 3.6° pre-op (−11° to 12°), changing to −2.4° (−14° to 8.2°) immediately post op and to −3.5° (−9.3° to 0.7°) at the latest follow up. The proportion of balanced shoulder improved from 14% pre-op to 14% immediately post op and to 65% at final follow up. No relation of pre-op T1 tilt and the final shoulder balance can be found. Discussion:. Shoulder balance is a dynamic feature. Patients can regain shoulder balance given time. We cannot tell whether this is due to their adaptive process or
Conventional wisdom holds that aseptic failure of proximal ingrowth femoral stems should be addressed by revision to a longer femoral stem dependent upon more distal fixation. This is a reliable and time-honoured strategy with a high likelihood of success provided secure initial fixation of the revision stem is obtained. Yet, stems reliant upon more distal diaphyseal fixation are accompanied by a greater risk of physiologic thigh pain attributable to the differential in flexural stiffness of the femoral shaft compared with the prosthetic stem. Contemporary proximal ingrowth femoral stems have become the most popular device used in total hip arthroplasty and are traditionally reserved for primary procedures. Nevertheless, the flat tapered design offers a tight fit between the medial and lateral endosteal cortices of the femur, unimpeded by an increasing anteroposterior dimension of the stem, and provides a secure geometrical block to
Background. A navigation system is useful tool to evaluate the intraoperative knee kinematics. Rheumatoid arthritis (RA) patients often need to have TKA operation, however, there are few TKA kinematics studies comparing RA and Osteoarthritis (OA) patients. Objective. The purpose of this study was to evaluate intraoperative TKA kinematics, and to describe the difference of kinematics between RA and OA patients. Materials and methods. Seventy-four patients, 86 knees were included in this study. Unilateral posterior stabilized TKAs were performed (male 14, female 72, age 70 ± 1.1 years) using navigation system. Sixty-one knees had OA and 25 had RA. Evaluation items are coronal gaps, AP translation and rotation. Coronal gaps were defined as the distance between the femoral and tibial cut surface. Medial and lateral gaps are also measured. AP translation was defined as the sagittal movement between the center of femoral and tibial condyle. Rotation was defined as axial difference of axis between femur and tibia. All items were evaluated by navigation system at every 10 degrees of knee flexion from 0 degrees of extension to 140 degrees of deep flexion. Results. In extension range, mean medial joint gaps (RA / OA) were 22.5 / 21.6 mm at 0 degree and decreased to 17.3 /15.0mm at 40 degrees, respectively. They were significantly different at 40 degrees. Lateral joint gaps were 16.4, 15.5mm at zero degree and slightly decreased to 21.0 / 20.0 mm at 40 degrees. In flexion range, mean medial joint gaps were 17.3 / 17.2 mm, 20.9 / 21.6 mm and 34.9 / 37.3 mm at 50 / 90 mm and 140 degrees. Mean lateral joint gaps were 16.4 / 15.5 mm, 21.8 / 21.6 mm and 29.0 / 31.4 mm. Both gaps were increased as knee was bent deeply(see Figure 1). Regarding to AP translation, femoral component was once moved 6.5 / 6.1 mm forward up to 50 degrees, then moved 25.8 / 23.5 mm backward with flexion. There was no significant difference (see Figure 2). Rotation kinematics showed significant difference in early flexion range. Consecutive external rotation of femur was recognized in RA group, but internal rotation was occurred in OA group from 0 to 60 degrees. External rotation was recognized in both groups from 60 degrees to deep flexion (see Figure 3). Conclusion. In this study, although joint gaps and AP translation were almost similar between RA and OA, it became clear that most significant difference was
Several authors have used 3D motion analysis to measure upper limb kinematics, but none have focused solely on wrist movements, in six degrees of freedom, during activities of daily living (ADL). This study aimed to determine the role of the different planar wrist movements during three standardised tasks, which may be affected by surgical procedures. Nine volunteers (age range 22-45) were recruited and each participant performed three simulated ADLs: using a door lever, a door knob and opening/closing a jam jar. The ADLs were simulated using a work-sim kit on an isokinetic dynamometer. Motion analysis was performed by a 10-camera Oqus system (Qualisys Medical AB, Gothenburg, Sweden). All raw kinematic data were exported to Visual3D (C-Motion Inc.), where the biomechanical model was defined and joint kinematics calculated. Table 1 shows a similar range of radial-ulnar deviation and flexion-extension as previous studies. However a substantial amount of wrist rotation also occurred in all tasks. This was significantly greater when using the door lever compared with the door knob and jam jar tasks. Previous studies have stated that a negligible degree of rotation occurs at the wrist. This study found a maximum mean of 31.7 degrees of wrist rotation. This indicates that considerable
At present, wear investigations of total hip replacement (THR) are performed in accordance with the ISO standard 14242, which is based on empirically determined relative motion data and exclusively describes the gait cycle. However, besides continuous walking, a number of additional activities characterize the movement sequences in everyday life and influence the wear rates as well as the size and shape of wear debris. Disagreements of in vitro and in vivo wear mechanisms seemed to be a result of differences between in vitro and in vivo kinematics and dynamics. This requires an optimization of the current test procedures and parameters. Hence, the aim of the present study was to evaluate most frequent activities of daily living, based on available in vivo data, in order to generate parameter sets according to loading and rotational movements close to the physiological situation. For the generation of angular patterns, time-dependent three-dimensional trajectories of reference points were used from the HIP98 database of Bergmann. The data set was evaluated and interpolated using analytical techniques to simulate consecutive smooth motion cycles in hip wear simulators or further test devices. The calculated relative joint movement was expressed by an ordered set of three elementary rotations and was complemented with three force components of the joint contact force to generate kinematically and dynamically consistent parameter sets. The obtained sets included the activities walking, knee bending, stair climbing and a combined load case of sitting down and standing up for an averaged patient. Generated slide tracks, created by the use of the angular patterns, demonstrated differences according to the kinematics between selected daily life activities and those established for the ISO standard 14242. In particular, for the relative flexion-extension
Aim: Postraumatic elbow stiffness is a common condition after elbow trauma. Sometimes it is a quite disabling symptom not responding to conservative measures. We present the surgical treatment of such cases of posttraumatic elbow stiffness. Material: Twenty three patients, fourteen male and nine female with an average age of 34 yrs, underwent a surgical treatment of their stiff elbow. The average preoperative range of motion regarding elbow flexion-extension was 65° and the average
The aim of this study was to investigate how the rotational axis of the wrist moves as the hand goes from full ulna to full radial deviation. Fifty normal wrists in 25 subjects were assessed with a Polhemus Fastrak (TM) magnetic tracking system. The subjects, aged 19 to 57, placed their palms on a flat wooded stool. Sensors were attached over their 3rd metcarpal and distal radius. The sensors then recorded movement from ulna to radial deviation. The translational and rotational measurement accuracies were 1 mm and 1 degree respectively. The mean range of movement was 45 degrees (SD 7). In ulna deviation the axis was in the region of the lunate. As the hand moved towards radial deviation, the axis moved distally. At the end of the movement the mean distal displacement was 21 mm (SD 15). In 32 wrists the distal displacement was accompanied by a mean displacement towards the ulna of 12 mm (SD 8). In 18 wrists the distal displacement was accompanied by a mean displacement towards the radius of 8 mm (SD 5). The rotational axis position indicates how the wrist is moving during radial deviation. In early movement, when the axis is proximal, there is a high degree of sideways translation. In later movement, when the axis is distal, there is more
Aim: The aim of this investigation was to determine how the rotational axis of the wrist moves as the hand goes from full ulna to full radial deviation. Materials &
Methods: Ulna to radial deviation was assessed in 30 normal wrists in 15 normal subjects aged 19 to 32. Movement was measured with a Polhemus Fastrak (TM) magnetic tracking system. The system has translational and rotational measurement accuracies of 1 mm and 1 degree respectively. Subjects placed their palms on a flat wooded stool and had movement sensors attached over their 3rd metacarpal and distal radius. These sensors then recorded movement as the hand moved from full ulna to full radial deviation. Results: The mean range of movement was 47 degrees (SD 8). In full ulna deviation the wrist rotational axis was in the region of the lunate/capitate. As the hand moved towards radial deviation, the axis moved distally. At the end of the movement the mean distal displacement was 22 mm (SD 14). In 17 wrists the distal displacement was accompanied by mean displacement towards the ulna of 13 mm (SD 8). In 13 wrists the distal displacement was accompanied by a mean displacement towards the radius of 7 mm (SD 5). Conclusion: The rotational axis position indicates how the wrist is moving during radial deviation. In early movement, when the axis is proximal, there is a high degree of sideways translation. In later movement, when the axis is distal, there is more
Aim: The carpal bone arrangement can be described as a matrix of two rows and three columns. There a various theories as to how the bones within the matrix move during ulna to radial deviation. One theory suggests that there are two types of wrist movement, namely Row &
Column. 1. . The aim of this study was to investigation how the rotational axis of the wrist moves as the hand goes from full ulna to full radial deviation. Materials and Methods: Ulna to radial deviation was assessed in 50 normal wrists in 25 normal subjects aged 19 to 57. Movement was measured with a Polhemus Fastrak (TM) magnetic tracking system. The system has translational and rotational measurement accuracies of 1 mm and 1 degree respectively. Subjects placed their palms on a flat wooded stool and had movement sensors attached over their 3rd metcarpal and distal radius. These sensors then recorded movement as the hand moved from full ulna to full radial deviation. Results: The mean range of movement was 45 degrees (SD 7). In full ulna deviation the wrist rotational axis was in the region of the lunate. As the hand moved towards radial deviation, the axis moved distally. At the end of the movement the mean distal displacement was 21 mm (SD 15). In 32 wrists the distal displacement was accompanied by mean displacement towards the ulna of 12 mm (SD 8). In 18 wrists the distal displacement was accompanied by a mean displacement towards the radius of 8 mm (SD 5). Conclusion: The rotational axis position indicates how the wrist is moving during radial deviation. In early movement, when the axis is proximal, there is a high degree of sideways translation. In later movement, when the axis is distal, there is more
Introduction: The anterior femoroacetabular impingement syndrome has so far been a great unknown in orthopedic surgery. It is typically characterized by pain when the hip is subjected to the flexion – adduction – internal
Rotational instability is defined as combined medial and lateral ligament instability of the ankle joint. In the case of combined injury to the posterior syndesmosis and posterior joint portion the typical giving-away-symptoms and the therapy resistant complaints are accompanied. In the following prospective study 43 patients between the ages of 16 and 35 with the average age of 23.9 years with posttraumatic chronic joint-instability as well as posterior syndosmosis insufficiency were examined. The treatment of rotational instability was performed by an anchoring technique modified by Broström. The resulting insufficiency of the posterior syndesmosis was treated by a Tight Rope provided by Arthrex. The study was run over 14 months, where only 36 out of 43 patients were available for postoperative follow up. A preoperative baseline 2-view x-ray as well as an MRI was performed in all patients. The operation to establish the stability of the ligaments via anchoring-technique and the treatment of the posterior syndesmosis through Tight-Rope were performed via arthroscopy of the ankle joint with additional inspection of the posterior joint portion. At the same time existent impingements were recessed. In each patient the AOFAS score as an indicator for the treatement outcome and the VAS-score was used as the measurement for the level of pain developement were used. The first exam was performed in preoperative setting followed by subsequent 12 and 24 weeks as well as 12 and 14 months postoperatively. To ensure stability a preoperative x-ray in suppination stress was performed followed by the same type of x-ray 3 months postoperatively. A significant improvement in the above mentioned scores were noted already 3 months after the operation. An improvement in VAS-score of 5.1 points as well as in AOFAS-score of 79% was observed. The degree of Suppination and