Restoration of anatomy is paramount in total hip arthroplasty (THA) to optimise function and stability.
Introduction. Correct postoperative leg length restoration is among the most important goals of hip arthroplasty. Therefore, we developed, validated and clinically applied a novel software algorithm based on surgical navigation, which allows the surgeon to restore a defined femur position without establishing a femoral coordinate system or the hip joint center and measure the leg length accurately and simply. Material and Methods. This new leg length algorithm was used in 154 hips (145 patients) that underwent CT-based computer-assisted THA (VectorVision Build 274 prototype; BrainLAB AG, Helmstetten, Germany) with a tissue preserving superior capsulotomy. Intraoperatively, a pelvic and a femoral dynamic reference bases (DRB) were applied and the anterior pelvic plane (APP) was set as the pelvic coordinate system. Then, the hip joint was put in a neutral position and this position, and the relative position of the femoral DRB relative to the pelvic DRB, was captured and stored by the navigation system. After implantation of the prosthesis the same above described femoral position with the same amplitude of flexion/extension, abduction/adduction and rotation was restored. Now, any resulting difference was due to linear changes. Validation of this new algorithm was performed by comparing the navigated results to measurements from calibrated antero-posterior pre- and postoperative radiographs. The radiographic results were compared to the mean leg length change measured with the navigation system. Results. No significant difference was found between radiographic leg length change and the results from the navigation system (p=0.658). The mean difference between the radiographic results and the results from the navigation system was −0.5 (1–8 mm (range, −5–4 mm). The mean registration accuracy of the navigation system was 2.04 (0.58 mm (range, 0.70–3.00 mm). Discussion. This novel tool has the potential to increase the accuracy and consistency of
Leg length discrepancy (LLD) is a common sequalae of limb reconstruction procedures. The subsequent biomechanical compensation can be directly linked to degenerative arthritis, lower back pain, scoliosis and functional impairment. It becomes particularly problematic when >2cm, established as a clinical standard. This two-arm experimental study assesses how reliable an iPhone application is in the measurement of LLD at different distances in control and LLD patients. 42 participants were included in the study, divided evenly into 21 control and 21 LLD patients. A standardised measurement technique was used to obtain TMM and iPhone application measurements, taken at a distance of 0.25m, 0.50m and 0.75m.Introduction
Materials and Methods
Percutaneous drill epiphyseodesis is an effective method of achieving physeal ablation with no significant complications. While the growth remaining method is a crude estimate of the timing of epiphyseodesis, it was accurate in the majority of cases in this small series. The determination of skeletal age was found to be a useful adjunct to management in a small proportion of cases.
Introduction. Restoration of anatomy is essential in total hip arthroplasty (THA) to optimize function and stability.
We sought to determine the short to medium-term clinical and radiographic outcomes using a short stem in young adults with a proximal femoral deformity (PFD). We prospectively studied 31 patients (35 hips) with PFDs treated with an uncemented primary THA using a short stem with cervicometaphyseal fixation between 2011–2018. There were 19 male (23 hips) and 12 female (12 hips) patients, with a mean BMI of 26.7±4.1 kg/m. 2. Twelve cases had a previous surgical procedure, and six of them were failed childhood osteotomies. Mean age of the series was 44±12 years, mean follow-up was 81±27 months and no patients were lost to follow-up. PFDs were categorized according to a modified Berry´s classification. Average preoperative
The variables involved in a robotic THA can exceed 52: many parameters as pelvic orientation with CT scan, templating, offset, and
Introduction. Circumferential periosteal release is a rarely reported procedure for paediatric limb lengthening. The technique involves circumferential excision of a strip of periosteum from the metaphysis of the distal femur, tibia and fibula. This study aims to determine the mid to long-term effectiveness of this technique. Materials and Methods. A retrospective case series was performed of all patients undergoing circumferential periosteal release of the distal femur and/or tibia between 2006 and 2017. Data collected included demographics, surgical indication, post-operative limb-lengths and complications. Data collection was stopped if a further procedure was performed that may affect limb-length (except a further release).
Robotic assisted surgery aims to reduce surgical errors in implant positioning and better restore native hip biomechanics compared to conventional techniques for total hip arthroplasty (THA). The primary objective of this study was to compare accuracy in restoring the native centre of hip rotation in patients undergoing conventional manual THA versus robotic-arm assisted THA. Secondary objectives were to determine differences between these treatment techniques for THA in achieving the planned combined offset, cup inclination, cup version, and
Introduction. Primary robotic-arm assisted total hip arthroplasty (THA) yields more accurate and reproducible acetabular cup placement, nonetheless, data is scarce in terms of outcomes. The purpose of the present study was to report on patient-reported outcomes (PROMs) in a large group of patients who underwent robotic-arm assisted THA. The authors hypothesized that (1) patients who underwent robotic-arm assisted primary THA would achieve favorable and significant improvement in PROMs, (2) an accurate and reproducible acetabular cup placement with respect to the defined SafeZones would be obtained, and (3) a low rate of THA dislocation would be observed. Methods. Prospectively collected data were retrospectively reviewed between April 2012 to May 2017. Primary THA using Mako Robotic-Arm [Mako Surgical Corp. (Stryker), Fort Lauderdale, FL, USA] with minimum two-year follow-up for the Harris Hip Score (HHS) and the Forgotten Joint Score-12 (FJS-12) were included. Exclusion criteria were: bodymass index (BMI) > 40 kg/m2, age < 21-year old, worker's compensation, or unwilling to participate. Visual analog scale (VAS) for pain and patient satisfaction were obtained. Intraoperative measurements for
Introduction. Computer navigation is a highly sophisticated tool in orthopedic surgery for component placement in total hip arthroplasty (THA). A number of recommendations have been published. Although Lewinnek's safe-zone is the best-known among these its significance is questioned in recent years since it addresses the acetabular socket only ignoring the femoral stem. Modern target definitions consider both socket and stem and provide well-defined recommendations for complementary component positioning. We present a new small-sized hand-held imageless navigation system that implies these targets and supports the surgeon in realizing the concept of combined anteversion and combined Target-Zone (cTarget- Zone) in THA and to control leg length and offset without altering the standard surgical work-flow and we report initial results. Methods. The targets for positioning the components of a total hip as expressed by radiographic cup inclination (cRI) and anteversion (cRA), stem antetorsion (sAT) and neck-to-shaft angle (sNSA) are determined for a specific prosthesis system using a computerized 3D-model. The optimizing goal is maximizing the size of the cSafe-Zone providing the largest target zone for an impingement-free prosthetic range of motion (pROM) in order to minimize the risk for dislocation in physiologic and combined movements. Independent parameters like head size, head-to-neck ration and also component orientations like cRI, cRA, sAT and sNSA were varied systematically and the optimal cSafe-Zone was computed in semi-automated batch runs. These optimized prosthesis-specific results were introduced into the software of the hand-held navigation system. This system measures leg length, offset, acetabular and femoral head centers intraoperatively. Results. In contrast to Lewinnek the outline of our cSafe-Zone is not rectangular but polygonal. Its size shows prosthesis-specific maxima. The largest zones are found for optimal sNSA values at 126° +/−4°, optimal ranges for cRI depend on head size and range from 44° to 36°, best sAT range from 10° to 18°, cRA from 18° to 25°. There is a prosthesis- specific linear correlation between sAT and cRA that denotes the combined anteversion. The target value for combined anteversion is not dependent on pelvic tilt but on sNSA. The hand-held navigation system displays all these orienting parameters as well as
The fear of high complication rates, repeated surgery and component mal positioning, especially early in the surgeon’s experience, can be an obstacle for starting a new technique like minimally invasive THR. The aim of the present investigation was to report on our learning curve of the first 100 consecutive minimally invasive total hip replacements through an anterior approach and to focus on intraoperative and postoperative complications as well as on the quality of implant positioning. In order to have a comparison, the last 100 THR performed through our previously used direct lateral approach were retrospectively evaluated. In both groups, complex acetabular and femoral reconstructions were excluded as they were performed though a digastric trochanteric osteotomy. Every change of the initial surgical plan was considered an intraoperative, every change in the rehabilitation plan considered a postoperative complication. The quality of implant positioning was evaluated in a standardized anteroposterior pelvic x-ray and a cross table lateral view at the 3 month follow-up visit and included the positioning of the cup and the stem in both views and the amount of
From 1990 to 2003 the Ilizarov technique was used to treat 41 patients affected by the following congenital or acquired deformities : post-poliodeformity (n=8), hemimelia (n=6), pseudoachondroplasia (n=5), idiopathic genu valgum/varum (n=5), hypoplasia (n=3), osteomyelitis with growth arrest (n=3), DDH (n=2), rickets (n=2), Blount disease (n=2), Ollier disease (n=1), Perthes disease (n=1), arthrogryposis (n=1), hypochondroplasia (n=1) and congenital genu flexum (n=1). Post-traumatic deformities and simple
In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years).Aims
Methods
Background. New marker free motion analysis systems are being used extensively in the area of sports medicine and physiotherapy. The accuracy and validity of use in an orthopaedic setting have not been fully assessed for these newer marker free motion analysis systems. The aim of this study is to compare leg length and varus/valgus knee measurements performed by leg measurement x-ray, and performed using the new marker free motion analysis system (Organic motion biostage). Methods. Patients attending the orthopaedic department for total knee replacements were recruited. They underwent radiological leg measurement x-ray, clinical leg measurement, and finally assessment using the organic motion biostage system. These were analysed using the motion monitor software, microsoft excel and minitab 16. Results. For 23 patients assessed, all methods showed a statistically significant result (p<0.05) using paired t-tests. This rejects the null hypothesis- indicating that organic motion does not have the accuracy currently to measure leg length or knee varus/valgus angle. Conclusions. Results indicate that the organic motion biostage system- a new marker free motion analysis system, is not feasible currently as a method of accurately measuring
Ilium is the most common site of pelvic Ewing’s sarcoma (ES). Resection of the ilium and iliosacral joint causes pelvic disruption. However, the outcomes of resection and reconstruction are not well described. In this study, we report patients’ outcomes after resection of the ilium and iliosacral ES and reconstruction with a tibial strut allograft. Medical files of 43 patients with ilium and iliosacral ES who underwent surgical resection and reconstruction with a tibial strut allograft between January 2010 and October 2021 were reviewed. The lesions were classified into four resection zones: I1, I2, I3, and I4, based on the extent of resection. Functional outcomes, oncological outcomes, and surgical complications for each resection zone were of interest. Functional outcomes were assessed using a Musculoskeletal Tumor Society (MSTS) score and Toronto Extremity Salvage Score (TESS).Aims
Methods
Introduction. Prosthetic replacement remains the treatment of choice for displaced femoral neck fractures in the elderly population, with recent literature demonstrating significant functional benefits of total hip arthroplasty (THA) over hemiarthroplasty. Yet the fracture population also has historically high rates of early postoperative instability when treated with THA. The direct anterior approach (DAA) may offer the potential to decrease the risk of postoperative instability in this high-risk population by maintaining posterior anatomic structures. The addition of intraoperative fluoroscopy can improve precision in component placement and overcome limitations on preoperative planning due to poor preoperative radiographs performed in the emergency setting. Methods. We retrospectively reviewed clinical and radiographic outcomes of 113 consecutive patients with displaced femoral neck fractures treated by two surgeons over a five-year period. All underwent surgery via the DAA using fluoroscopic guidance, and were allowed immediate postoperative weight bearing without any hip precautions or restrictions. Charts were reviewed for relevant complications, while radiographs were reviewed for component positioning, sizing, and leg length discrepancy. Mean follow-up was 8.9 months. Results. Mean age was 79.3 years (range, 42 to 101), 73% of patients were women, and mean BMI was 22.6 kg/m. 2. Ninety patients (80%) received THA while 23 (20%) received unipolar or bipolar hemiarthroplasty. Mean acetabular anteversion was 15.0 degrees (range, 4 to 24) and mean abduction was 39.2 degrees (range, 27 to 51) with 95% of acetabular components in the combined safe zone as described by Lewinnek. Mean radiographic
With increasing burden of revision hip arthroplasty (THA), one of the major challenges is the management of proximal femoral bone loss associated with previous multiple surgeries. Proximal femoral arthroplasty (PFA) has already been popularized for tumour surgeries. Our aim was to describe the outcome of using PFA in these demanding non-neoplastic cases. A retrospective review of 25 patients who underwent PFA for non-neoplastic indications between January 2009 and December 2015 was undertaken. Their clinical and radiological outcome, complication rates, and survival were recorded. All patients had the Stanmore Implant – Modular Endo-prosthetic Tumour System (METS).Aims
Methods
There has been a trend towards operative management of pelvic injuries. Posterior pelvic integrity is more important for functional recovery. Percutaneous iliosacral screw fixation is being increasingly preferred for posterior pelvic stabilisation. Outcome reporting for this procedure remains inconsistent and un-standardised. Retrospectively, all percutaneous iliosacral screw fixations done at this institute during a 5-year period (2008–2012) were reviewed. 28 patients, who had had at least 12 months follow-up, were contacted and clinical scoring was done by postal correspondence. Radiographs were measured for displacements and