Search Our Scientific Publications & Authors

Sci Rep 2021 05 20;11(1):10650. Epub 2021 May 20.

Laboratory of Gait and Movement Analysis, Orthopedic Hospital Vienna-Speising, Vienna, Austria.

3D free-hand ultrasound (3DFUS) is becoming increasingly popular to assist clinical gait analysis because it is cost- and time-efficient and does not expose participants to radiation. The aim of this study was to evaluate its reliability in localizing the anterior superior iliac spine (ASIS) at the pelvis and the hip joint centers (HJC). Additionally, we evaluated its accuracy to get a rough estimation of the potential to use of 3DFUS to segment bony surface. Read More

Knee 2021 Mar 24;29:150-159. Epub 2021 Feb 24.

Department of Physical Therapy, School of Physical Education, Physical Therapy and Occupational Therapy, Universidade Federal de Minas Gerais, Brazil. Electronic address:

Background: Some traditional single-leg squat tests focused on number of repetitions may not demand precise control of lower limb dynamic alignment, especially in the frontal and transverse planes. The primary objective of this study was to evaluate test-retest reliability and construct validity of a novel single-leg squat test - the 'precision-squat test' (PST) - designed to assess performance under varying task demands that can impact the execution of lower limb movements. A secondary objective was to investigate whether musculoskeletal factors predict performance in the PST in healthy individuals. Read More

J Orthop Surg (Hong Kong) 2020 Sep-Dec;28(3):2309499020962860

Department of Orthopaedic Surgery, Kochi Medical School, Nankoku, Japan.

Purpose: To evaluate cup-positioning accuracy in total hip arthroplasty (THA) using a novel angle-adjusting alignment guide with laser pointer and determine whether level of surgical experience affects accuracy of cup placement or not.

Methods: We included 117 hips in 104 patients who underwent THA using the novel guide. We retrospectively reviewed 44 hips in 40 patients who underwent THA before the novel guide was introduced. Read More

J Am Vet Med Assoc 2020 Aug;257(3):299-304

Objective: To examine the effectiveness of applying selective pressure to improve hip joint quality in purpose-bred detection dogs by use of PennHIP distraction index (DI) values along with Orthopedic Foundation for Animals (OFA) hip joint scores and to determine whether age, sex, coat color, breed, and body weight were associated with hip joint quality.

Animals: 615 purpose-bred detection dogs assessed for hip joint quality.

Procedures: Orthopedic records of 615 purpose-bred detection dogs (569 Labrador Retrievers and 46 Labrador Retriever-German Wirehaired Pointer crossbred dogs) from 2000 through 2017 were analyzed. Read More

Oper Orthop Traumatol 2020 Apr 28;32(2):107-115. Epub 2019 Nov 28.

Department of Orthopedic, Trauma and Plastic Surgery, University of Leipzig, Leipzig, Germany.

Objective: The aim is to address core decompression and pathologies of the femoral head, treating them during the same procedure. Furthermore, radiation exposure will be reduced.

Indications: Femoral head necrosis ARCO (Association Research Circulation Osseous) stages I-III. Read More

Technol Health Care 2020 ;28(3):315-323

Department for Orthopaedic Surgery, University of Greifswald, Greifswald, Germany.

Background: Incorrect cup positioning in primary total hip arthroplasty is known as a risk factor for early implant failure. The use of navigation systems leads to more accurate cup positioning.

Objective: The aim of this study was to compare the registration accuracy of the anterior pelvic plane and the measurement accuracy of the definite cup position for a pointer computer-assisted orthopaedic navigation system (P-CAOS) and an ultrasound-based navigation tool (US-CAOS) in an intra-individual study design. Read More

Orthop J Sports Med 2019 Jan 9;7(1):2325967118820507. Epub 2019 Jan 9.

The Stadium Sports Medicine Clinic, Sydney, New South Wales, Australia.

Open Orthop J 2016 22;10:26-35. Epub 2016 Mar 22.

Department of Orthopaedic Surgery, Institute of Clinical Medicine, and University Hospital, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.

Background: In cementless total hip arthroplasty, imageless computer-assisted navigation is usually used to register the anterior pelvic plane (APP). The accuracy of this method is influenced by the subcutaneous tissues overlying the registration landmarks. On the other hand, the acetabular center axis (ACA) is determined from the acetabular rim. Read More

J Phys Ther Sci 2016 Jan 29;28(2):632-4. Epub 2016 Feb 29.

Department of Physical Therapy, College of Biomedical Science and Engineering, Inje University, Republic of Korea.

[Purpose] The purpose of this study was to investigate activities of the hip extensors and erector spinae during bridging exercise by using instruments with a laser pointer on the pelvic belt. [Subjects] Twelve subjects (age, 23 to 33 years) with non-specific low back pain volunteered for this study. [Methods] Subjects performed bridging exercises with and without trajectory exercises by using a laser pointer fixed to a pelvic strap. Read More

Cochrane Database Syst Rev 2016 Mar 14;3:CD003004. Epub 2016 Mar 14.

Patient Safety Research, Royal Lancaster Infirmary, Pointer Court 1, Ashton Road, Lancaster, UK, LA1 1RP.

Background: Proximal femoral fracture (PFF) is a common orthopaedic emergency that affects mainly elderly people at high risk of complications. Advanced methods for managing fluid therapy during treatment for PFF are available, but their role in reducing risk is unclear.

Objectives: To compare the safety and effectiveness of the following methods of perioperative fluid optimization in adult participants undergoing surgical repair of hip fracture: advanced invasive haemodynamic monitoring, such as transoesophageal Doppler and pulse contour analysis; a protocol using standard measures, such as blood pressure, urine output and central venous pressure; and usual care. Read More

Anesthesiology 2015 Dec;123(6):1481-2

Mayo Clinic, Rochester, Minnesota.

Int J Comput Assist Radiol Surg 2015 Jun 18;10(6):761-71. Epub 2015 Apr 18.

Department of Computer Science, Johns Hopkins University, Baltimore, MD, 21218, USA,

Purpose: We present a registration method for computer-assisted total hip replacement (THR) surgery, which we demonstrate to improve the state of the art by both reducing the invasiveness of current methods and increasing registration accuracy. A critical element of computer-guided procedures is the determination of the spatial correspondence between the patient and a computational model of patient anatomy. The current method for establishing this correspondence in robot-assisted THR is to register points intraoperatively sampled by a tracked pointer from the exposed proximal femur and, via auxiliary incisions, from the distal femur. Read More

Clin Sports Med 2013 Apr 8;32(2):325-30. Epub 2013 Feb 8.

Primary Care Sports Medicine Fellow, Department of Family Medicine, University of Connecticut, Hartford, CT 06088, USA.

The term, hip pointer, is applied in the setting of a blunt trauma injury to the iliac crest. It typically occurs in contact and collision sports and can cause significant pain and loss of practice or game time. A direct blow results in subperiosteal edema with hematoma formation within surrounding muscle or soft tissue and bone contusion of the iliac crest. Read More

J Fam Pract 2012 Dec;61(12):736-44

Division of Sports Medicine, Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA.

When a patient who's physically active complains of hip pain, don't be too quick to label it a "hip pointer" that requires time and rest to heal. Consider this more nuanced-and effective-approach. Read More

PLoS One 2012 1;7(8):e41583. Epub 2012 Aug 1.

Biomechanics and Movement Science Program, University of Delaware, Newark, Delaware, United States of America.

Background: Studies of human upright posture typically have stressed the need to control ankle and hip joints to achieve postural stability. Recent studies, however, suggest that postural stability involves multi degree-of-freedom (DOF) coordination, especially when performing supra-postural tasks. This study investigated kinematic synergies related to control of the body's position in space (two, four and six DOF models) and changes in the head's orientation (six DOF model). Read More

Biomed Tech (Berl) 2012 May 16;57(4):239-48. Epub 2012 May 16.

Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Germany.

In total hip replacement, patient placement in the lateral position is preferred by many surgeons. However, it complicates registration of the so-called pelvic coordinate system that is the standard reference for surgeons to measure cup orientation. This coordinate system comprises the anterior pelvic plane and the mid-sagittal plane, and it is conventionally registered on the basis of bony anatomical landmarks including the left and the right anterior superior iliac spine (ASIS). Read More

J Nat Sci Biol Med 2012 Jan;3(1):52-9

Department of Anthropology, University of Delhi, Delhi, India.

Objective: To study the relationship of ethnicity with overweight/obesity, variation in adiposity levels, regional distribution of fat and its impact on cardio-respiratory health among selected ethnic groups.

Materials And Methods: A cross-sectional study was carried out among 300 young adults of three ethnic groups from different geographical regions of India ranging in age from 20 to 30 years. Stature, weight, circumferences, body fat percentage, and skinfold thicknesses were measured. Read More

Technol Health Care 2010 ;18(4-5):341-51

Orthopaedic Department, Center for Musculoskeletal Surgery, Charité, Berlin, Germany.

Background: Precise identification of bony landmarks by use of pointer based navigation systems is influenced by thickness of soft tissue. Ultrasound-based navigation systems try to overcome the problems of positional deviation associated with soft tissue. The aim of the study was to investigate the influence of the BMI and the thickness of the soft tissue on the post-operative cup position and accuracy in the application of an ultrasound-based (US CAOS) and a pointer-based navigation system (P CAOS). Read More

Comput Aided Surg 2010 10;15(4-6):75-82. Epub 2010 Nov 10.

Institute of Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland.

Introduction: A novel computerized algorithm for hip joint motion simulation and collision detection, called the Equidistant Method, has been developed. This was compared to three pre-existing methods having different properties regarding definition of the hip joint center and behavior after collision detection. It was proposed that the Equidistant Method would be most accurate in detecting the location and extent of femoroacetabular impingement. Read More

Oper Orthop Traumatol 2010 Jul;22(3):307-16

LVR Klinik für Orthopädie, Viersen, Germany.

Objective: Precise implantation of hip resurfacing arthroplasty by imageless computer navigation. Hence a malalignment of the femoral component, leading to early loss of the implant, can safely be avoided.

Indications: Coxarthrosis in patients with normal bone mineral density; only minor deformity of the femoral head that enables milling around the femoral neck without notching. Read More

Arch Orthop Trauma Surg 2011 Feb 20;131(2):167-72. Epub 2010 May 20.

Department of Orthopaedic Surgery, ENDO-Klinik Hamburg GmbH, Germany.

Introduction: Arthroscopic femoral osteoplasties might be technically demanding, might cause prolonged operative times and restrict the intraoperative overview. An automated navigated matching process of preoperative CT-data and intraoperative fluoroscopy should allow for noninvasive registration for FAI-surgery.

Method: Six hip joints were used with a conventional navigation system. Read More

Cases J 2009 Jun 29;2:6487. Epub 2009 Jun 29.

Department of Orthopaedics, Government Hospital for Bone and Joint Surgery Barzullah Srinagar, 190005 India.

Introduction: Ewing's sarcoma is second most common primary malignant bone neoplasm in children and adolescents. We report a case of Ewing's sarcoma of ilium in an 18-year-old female mimicking clinically and radiologically inflammatory arthritis of hip joint, a rare entity not mentioned in literature.

Case Presentation: An 18-year-old girl presented with pain hip, limp and fever off and on. Read More

Orthopedics 2008 Oct;31(10 Suppl 1)

Orthopaedic Department, Charite, Chariteplatz 1, 10117 Berlin, Germany.

The use of navigation techniques in primary total hip arthroplasty improves the position of endoprosthetic components, especially cup positioning. An intraoperative registration of the anterior pelvic plane is necessary to define the anteversion and inclination angles on the acetabular side. This study compares the accuracy of manual pointer palpation to ultrasound registration in navigation to determine pelvic plane registration in 60 cases of minimally invasive surgical technique. Read More

Zhonghua Yi Xue Za Zhi 2008 Dec;88(45):3226-9

Department of Orthopedics, Shanghai 10th People's Hospital, Shanghai 200072, China.

Objective: To investigate the effect of a new technique of navigated percutaneous placement of iliosacral screws using intra-operative three-dimensional (3D) imaging.

Methods: Sixteen patients with hip fracture were placed in supine position. After the reference marker was fixed on the iliac crest, a 3-D C-arm navigation system was used intra-operatively to obtain 3D images that were transferred to the navigation system by an automatic. Read More

Proc Inst Mech Eng H 2007 Oct;221(7):739-53

mNemoscience, Obach-Palenberg, Germany.

Computer assisted orthopaedic surgery (CAOS) technology has recently been introduced to overcome problems resulting from acetabular component malpositioning in total hip arthroplasty. Available navigation modules can conceptually be categorized as computer tomography (CT) based, fluoroscopy based, or image-free. The current study presents a comprehensive accuracy analysis on the computer assisted placement accuracy of acetabular cups. Read More

Orthopedics 2007 Oct;30(10 Suppl):S153-6

Department of Orthopaedic and Trauma Surgery, Lukas Krankenhaus, Biinde, Germany.

Intraoperative registration of the anterior pelvic plane is necessary for navigation during total hip arthroplasty (THA). Ultrasound referencing of bony landmarks was implemented in a THA navigation system (OrthoPilot, B. Braun Aesculap; Tuttlingen, Germany) as an alternative to pointer palpation. Read More

Gait Posture 2007 Oct 8;26(4):560-71. Epub 2007 Feb 8.

Movement Analysis Laboratory, Istituti Ortopedici Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy.

Human movement analysis still suffers from the weakness of the currently used protocols for data collection and reduction. Reliable data comparisons and precise functional assessment require anatomically based definitions of the reference axes and frames, and therefore careful identification and tracking of the landmarks. When impaired children are analysed, the marker-set and other measurement procedures have to be minimised to reduce the time of the experiment and ensure patient collaboration. Read More

Comput Aided Surg 2005 Sep-Nov;10(5-6):329-36

Department of Orthopaedic Surgery, Inselspital.

Using a total of 30 cadaveric hips, the accuracy of a fluoroscopy-based computer navigation system for cup placement in total hip arthroplasty (THA) was investigated and an error analysis was carried out. The accuracy of placing the acetabular component within a predefined safe zone using computer guidance was compared to the precision that could be achieved with a freehand approach. Accurate control measurements of the implanted cup were obtained using fiducial-based matching to a pre-operative CT scan with respect to the anterior pelvic plane. Read More

Comput Aided Surg 2004 ;9(3):59-69

Maurice E. Müller Research Center for Orthopaedic Surgery, Institute for Surgical Technology and Biomechanics University of Bern Switzerland.

Objective: A simulator was developed to mimic commercial CAS systems in implementing most tasks required to carry out a surgical operation. As tracking systems are generally expensive components, an alternative solution based on low-cost video-based tracking was used. Video tracking accuracy was assessed to determine whether or not this kind of approach was suitable for use in the training domain. Read More