Introduction. Natural population variation in femoral morphology results in a large range of offsets, anteversion angles and lengths. During total hip arthroplasty, accurate restoration of hip biomechanics is essential to achieve good functional results. One option is to restore the anatomic hip rotation center. Alternatively, medializing the rotation center and compensating by increasing the femoral offset, reduces acetabular contact forces and increases the abductor lever arm. We investigated the ability of two cemented stem systems to restore hip biomechanics in an anatomic and medialized way. We compared an undersized “Exeter-type” of stem with three offset options and 18 sizes (CPT, Zimmer), to a line-to-line “Kerboul-type” of stem with proportional offset and 12 sizes (Centris, Mathys). Methods. Thirty CT scans of whole femora were segmented and the hip rotation center, proximal femoral axis and femoral length were determined with Mimics and 3-matic (Materialise). Using scripting functionality in the software, CAD design files of both stems were automatically sized and aligned along the proximal femoral axis to restore an anatomical and a 5 mm medialized hip rotation center. Stem size and position could be fine-tuned manually. The maximum distances between the prosthetic (PRC), the anatomic (ARC) and the medialized hip rotation center (MRC) were calculated (Fig. 1). Variations in femoral offset (ΔFO), anteroposterior (ΔAP) and proximodistal distance (ΔPD) were analyzed. Finally, the number of cases where the hip rotation center could be restored within 5 mm was reported. Results. Both implants allowed restoring the ARC accurately (mean distance PRC-ARC:
Introduction. The French paradox regarding cemented femoral components has not been resolved, so we compared the mechanical behavior of a French stem, the CMK stem (Biomet, Warsaw, IN, USA), with a collarless, polished, tapered stem (CPT, Zimmer, Warsaw, IN, USA) using an original biomechanical instrument. Materials and Methods. Two size-3
Introduction. This is a report of the outcome of management of congenital pseudoarthrosis of the tibia (CPT) at skeletal maturity. Materials and Methods. Retrospective study. Inclusion criteria:.
The Masquelet technique, also known as the ‘induced membrane technique’ has been utilised in adult reconstruction with varied success. However, there is limited literature on its use in children and this study aims to share our experience. Materials & Methods. Between 2014 and 2022, 7 children underwent bone defect/infection reconstruction using Masquelet technique, four for complications of Congenital Pseudoarthrosis of Tibia (CPT) treatment, two with chronic osteomyelitis and one for Osteogenesis imperfecta with infected nonunion. The length of the defect relative to the length of the bone (index of reconstruction expressed as a percentage), time to union and complications were evaluated with standard radiographs and from electronic medical records. Results. The mean age was 11 years and the procedure was done in five tibiae, one femur and a metatarsal. The mean time interval was 7.1 weeks between the first and second stage surgery. The mean index of reconstruction was 25.8% and the mean follow up period was 17 months. Though six patients achieved union with a mean time to union of 6.5 months (range 4.5 to 10), two patients with multiple previous surgeries for
Introduction. In cemented total hip arthroplasty (THA), proper cement mantle thickness in the femoral canal is still controversial subject. It is widely accepted that the cement mantle around a femoral stem should be at least 2 mm in thickness. But articles from France reported good long-term result with thin cement mantle. It is so called “The French paradox”. We have already reported that the greater compressive force at the cement-bone interface was seen in collarless polished tapered (CPT, Zimmer, USA) stem with thick cement mantle than that with thin cement mantle. However, the stem with thick cement mantle subsided more than with thin mantle. It may have a possibility to cause an early mechanical failure of cemented THA. We compared to stem and cement subsidence in various cement mantles using tantalum ball into cement in this study. Methods. A cemented stem model was used for this study with a
Thumb carpometacarpal (CMC) arthritis is a common and disabling condition that can be treated with an operative procedure. Before operative measures, patients typically undergo conservative treatment utilizing methods such as physical therapy and injections. This study aims to determine what clinical modalities are being used for preoperative evaluation and nonoperative therapy and the associated cost prior to operative intervention. We queried Truven Market Scan, a large insurance provider database to identify patients undergoing CMC arthroplasty from 2010 to 2017. Patients were identified by common Current Procedural Terminology (CPT) codes for CMC arthroplasty. All associated
Aim. Intracellular persistence of S. aureus is believed to be one of the major mechanisms leading to bone and joint infection (BJI) chronicity and relapses. Despite its poor intracellular activity, daptomycin (DAP) is increasingly used in the treatment of staphylococcal BJI. The well-known in vitro synergy of daptomycin with various betalactam antibiotics consequently led us to investigate whether these combinations enhance the activity of daptomycin against the intracellular reservoir of methicillin-susceptible (MSSA) and -resistant (MRSA) S. aureus in an ex-vivo model of human osteoblast infection. Method. Osteoblastic MG63 cells were infected for 2h with MSSA strain or its isogenic MRSA. After killing the remaining extracellular bacteria with lysostaphin, infected cells were then incubated for 24h with DAP, oxacillin (OXA) or ceftaroline (CPT) alone or in combination, at the intraosseous concentrations reached with standard human therapeutic doses. Intracellular bacteria were then quantified by plating cell lysates. Minimum inhibitory concentrations (MICs) of these molecules alone and in combination were determined using the checkerboard method at pH7, but also at pH5 to mimic intracellular conditions. Results. Compared to untreated cells, DAP reduced significantly intracellular inoculum for MRSA only (p<10–3). OXA and
It is generally accepted that children treated for congenital pseudarthrosis of the tibia (CPT) should be followed-up until skeletal maturity, before drawing conclusions about the efficacy of treatment. We undertook this study in order to evaluate the long-term results of treatment of
Introduction. At present, orthopaedic surgeons utilize either CT, MRI or X-ray for imaging a joint. Unfortunately, CT and MRI are quite expensive, non weight-bearing and the orthopaedic surgeon does not receive revenue for these procedures. Although x-rays are cheaper, similar to CT scans, patients incur radiation. Also, all three of these imaging modalities are static. More recently, a new ultrasound technology has been developed that will allow a surgeon to image their patients in 3D. The objective of this study is to highlight the new opportunity for orthopaedic surgeons to use 3D ultrasound as alternative to CT, MRI and X-rays. Methods. The 3D reconstruction process utilizes statistical shape atlases in conjunction with the ultrasound RF data to build the patient anatomy in real-time. The ultrasound RF signals are acquired using a linear transducer. Raw RF data is then extracted across each scan line. The transducer is tracked using a 3D tracking system. The location and orientation for each scan line is calculated using the tracking data and known position of the tracker relative to the signal. For each scan line, a detection algorithm extracts the location on the signal of the bone boundary, if any exists. Throughout the scan process, a 3D point cloud is created for each detected bone signal. Using a statistical bone atlas for each anatomy, the patient specific surface is reconstruction by optimizing the geometry to match the point cloud. Missing regions are interpolated from the bone atlas. To validate reconstructed models output models are then compared to models generated from 3D imaging, including CT and MRI. Results. 3D ultrasound, which now has FDA approval in the United States, is presently available for an orthopaedic surgeon to use. Error analyses have been conducted in comparison to MRI and CT scans and revealed that 3D ultrasound has a similar accuracy of less than 1.0 mm in the creation of a 3D bone and soft-tissues. Unlike CT and MRI scans that take in excess of 2–3 weeks to create human bones, 3D ultrasound creates bones in 4–6 minutes. Once the bones are created, the surgeon can assess bone quality, ligament and cartilage conditions, assess osteophytes, fractures and guide needles into the 3D joint space. The creation of 3D bones has been accurately assessed for the spine, shoulder, knee, hip and ankle joints. A 3D joint pre-operative planning module has also been developed for a surgeon to size and position components before surgery. Discussion. 3D ultrasound is an exciting new imaging technology available for orthopaedic surgeons to use in their practice. Existing
This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures. Using the National Surgical Quality Improvement Programme (NSQIP) database, patients who underwent common orthopaedic surgery procedures from 1 January to 31 December 2021 were extracted. Patient preoperative COVID-19 status, demographics, comorbidities, type of surgery, and postoperative complications were analyzed. Propensity score matching was conducted between COVID-19-positive and -negative patients. Multivariable regression was then performed to identify both patient and provider risk factors independently associated with the occurrence of 30-day postoperative adverse events.Aims
Methods
Introduction. It is well established that diabetic patients undergoing total knee arthroplasty (TKA) are more susceptible to infection, problematic wound healing, and have overall higher complication rates. However there is a paucity in current literature investigating the effects of hypoglycemia on TKA. The purpose of this study was to determine the effect of hypoglycemia on TKA revision (rTKA) incidence analyzing a national private payer database for procedures performed between 2007 and 2015 Q1. Methods. A retrospective review of a national private payer database within the PearlDiver Supercomputer application (Warsaw, IN, USA) for patients undergoing TKA with blood glucose levels ranging from 20 to 219 mg/ml, in increments of 10 mg/ml, was conducted. Patients who underwent TKA were identified by Current Procedural Terminology (CPT)-27447 and International Classification of Disease (ICD) code 81.54. Glucose ranges were identified by filtering for lab identifier values unique to the PearlDiver database. Revision TKA and causes for revision, including mechanical loosening, failure/break, periprosthetic fracture, osteolysis, infection, pain, arthrofibrosis, instability, and trauma) were identified with
Arthrofibrosis remains a dominant post-operative complication and reason for returning to the OR following total knee arthroplasty. Trauma induced by ligament releases during TKA soft tissue balancing and soft tissue imbalance are thought to be contributing factors to arthrofibrosis, which is commonly treated by manipulation under anesthesia (MUA). We hypothesized that a robotic-assisted ligament balancing technique where the femoral component position is planned in 3D based on ligament gap data would result in lower MUA rates than a measured resection technique where the implants are planned based solely on boney alignment data and ligaments are released afterwards to achieve balance. We also aimed to determine the degree of mechanical axis deviation from neutral that resulted from the ligament balancing technique. Methods. We retrospectively reviewed 301 consecutive primary TKA cases performed by a single surgeon. The first 102 consecutive cases were performed with a femur-first measured resection technique using computer navigation. The femoral component was positioned in neutral mechanical alignment and at 3° of external rotation relative to the posterior condylar axis. The tibia was resected perpendicular to the mechanical axis and ligaments were released as required until the soft tissues were sufficiently balanced. The subsequent 199 consecutive cases were performed with a tibia-first ligament balancing technique using a robotic-assisted TKA system. The tibia was resected perpendicular to the mechanical axis, and the relative positions of the femur and tibia were recorded in extension and flexion by inserting a spacer block of appropriate height in the medial and lateral compartments. The position, rotation, and size of the femoral component was then planned in all planes such that the ligament gaps were symmetric and balanced to within 1mm (Figure 1). Bone resection values were used to define acceptable limits of implant rotation: Femoral component alignment was adjusted to within 2° of varus or valgus, and within 0–3° of external rotation relative to the posterior condyles. Component flexion, anteroposterior and proximal-distal positioning were also adjusted to achieve balance in the sagittal plane. A robotic-assisted femoral cutting guide was then used to resect the femur according to the plan (Figure 2).
Introduction and aim. One of the suggested advantages of hip resurfacing arthroplasty is that it offers the possibility of straightforward revision. As the femoral canal is not violated during the resurfacing procedure, it is postulated that the outcome of revision surgery should be equivalent to that of a primary hip arthroplasty. The purpose of this study was to investigate whether revision was as straightforward and as successful as has been suggested. Method. 14 patients underwent revision surgery due to the failure of the femoral component of their Birmingham hip resurfacing. The femoral component was revised to a cemented Zimmer
Middle-aged female patients with painful hip arthritis often have high expectations, are physically active and are more likely to have underlying anatomical abnormalities such as DDH. Large hard bearing total hip replacement (THR) offer the possibilities of reduced wear and risk of dislocation. The patients in this series all had surgery in the private sector and were operated on by one surgeon. They were selected for a hard bearing THR on the basis of age, health and expectations. Large bearing metal-on-metal (MOM) THR became possible in 2003, with ceramic-on-ceramic (COC) bearings used in patients with allergies to metal. There were 90 patients in the MOM group and 92 patients in the COC group. The mean age was 60 and the commonest diagnosis was osteoarthritis in both groups. In the MOM group there were 8 complications: 2 deep infections, 1 death from PE, and 5 severe soft tissue reactions (pseudotumour). In the COC group there were 2 complications: 1 deep infection and 1 patient with intermittent squeaking. The patients in this study were closely matched in terms of age and lifestyles. All of them were operated on by a single high volume specialist hip surgeon. The results suggest a high risk of failure in female patients who have had MOM THR. Most of the failures had described discomfort in the hip for many months before revision surgery. All of the failures were associated with a cemented
Introduction. The success of total hip replacement in the young has consistently been worse both radiologically and clinically when compared to the standard hip replacement population. Methods. We describe the clinical and radiological outcome of 58 consecutive polished tapered stems (PTS) in 47 patients with a minimum of 10 years follow-up (mean 12 years 6 months) and compared this to our cohort of standard patients. There were 22
The direction of penetration of the femoral head following total hip replacement has been shown at revision to be superomedial, superior or superolateral. However, it is important to study well functioning components to describe normal patterns of wear. The aim of this study was to characterise the 3D direction of penetration in standard and HXLPE. A prospective double blind randomised control trial was conducted using Radiostereometric Analysis (RSA). Fifty-four subjects were randomised to receive hip replacements with either UHMWPE liners or HXLPE liners. All subjects received a cemented
Background. The new Fassier-Duval Telescopic IM System (FD-rod) has the advantage of a single entry point over the traditional telescopic rods such as the Bailey-Dubow or Sheffield rods. Although encouraging early results were presented by François Fassier, there is no formal publication in the literature as yet. Methods. The first 24 consecutive cases (age 1.5-12.5 years) with a minimum of 1 year follow-up (1-2.4 years) after femoral and/or tibial FD-rods were reviewed to assess complications involving migration, non-telescoping, joint intrusion, infections and re-operation rates in patients with Osteogenesis imperfecta (OI, 15 cases), congenital tibial pseudarthrosis (CPT) in Neurofibromatosis Type1 (NF1, 2 cases), and Epidermal Naevus syndrome (1 case). In 6 cases of patients with Hypophosphataemic Rickets FD-rods were combined with an Ilizarov frame. Results. The OI patient group had a 13% re-operation rate (2/15) for proximal rod migration and a 40% complication rate (6/15 cases): rod migration and limited telescoping (5), intra-operative joint intrusion (1). There were no infections. All NF1
We have prospectively followed up 191 consecutive primary total hip replacements utilising a collarless polished tapered (CPT) femoral stem, implanted in 175 patients between November 1992 and November 1995. At a mean follow-up of 15.9 years (range 14 – 17.5) 86 patients (95 hips) were still alive (25 men and 61 women) and available for routine follow up. Clinical outcome was determined from a combination of the Harris (HHS) and Oxford (OHS) hip scores. Radiological assessment was with antero-posterior radiographs of both hips and a lateral radiograph of the operated hip. The radiographs were evaluated using well-recognised assessment techniques. There was no loss to follow up, with clinical data available on all 95 hips. Five patients were too frail to undergo radiographic assessment, therefore radiological assessment was performed on 90 hips (95%). At the latest follow-up, the mean HHS was 78 (range 28 – 100) and the mean OHS was 36 (range 15 – 48). Stems subsided within the cement mantle, with a mean total subsidence of 2.1mm (range 0.4 – 24). Higher grades of heterotopic bone formation were significantly associated with males (p<0.001) and hypertrophic osteoarthritis (p<0.001). Acetabular wear was associated with increased weight (p<0.001) and male sex (p=0.005). Amongst the cohort, only 1 stem (1.1%) has been revised due to aseptic loosening. This patient required reaming of their canal prior to implantation, as a result of a previous femoral osteotomy. The rate of stem revision for any cause was 7.4% (7 stems), of which 4.2% (4 stems) resulted from infection following revision of the acetabular component. Twenty patients (21.1%) required some sort of revision procedure; all except 3 of these resulted from failure of the acetabular component. Cemented cups had a significantly lower revision burden (2.7%) than Harris Galante uncemented components (21.8%) (p<0.001). The
The aim of this study was to determine the impact of the severity of anaemia on postoperative complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA). A retrospective cohort study was conducted using the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database. All patients who underwent primary TKA or THA between January 2012 and December 2017 were identified and stratified based upon hematocrit level. In this analysis, we defined anaemia as packed cell volume (Hct) < 36% for women and < 39% for men, and further stratified anaemia as mild anaemia (Hct 33% to 36% for women, Hct 33% to 39% for men), and moderate to severe (Hct < 33% for both men and women). Univariate and multivariate analyses were used to evaluate the incidence of multiple adverse events within 30 days of arthroplasty.Aims
Methods