Aims

Achilles tendon re-rupture (ATRR) poses a significant risk of postoperative complication, even after a successful initial surgical repair. This study aimed to identify risk factors associated with Achilles tendon re-rupture following operative fixation.

Aims

The study aimed to assess the clinical outcomes of arthroscopic debridement and partial excision in patients with traumatic central tears of the triangular fibrocartilage complex (TFCC), and to identify prognostic factors associated with unfavourable clinical outcomes.

It is known that the gait dynamics of elderly substantially differs from that of young people. However, it has not been well studied how this age-related gait dynamics affects the knee biomechanics, e.g., cartilage mechanical response. In this study, we investigated how aging affects knee biomechanics in a female population using subject-specific computational models.

Two female subjects (ages of 23 and 69) with no musculoskeletal disorders were recruited. Korea National Institute for Bioethics Policy Review Board approved the study. Participants walked at a self-selected speed (SWS), 110% of SWS, and 120% of SWS on 10 m flat ground. Three-dimensional marker trajectories and ground reaction forces (Motion Analysis, USA), and lower limbs’ muscle activities were measured (EMG, Noraxon USA). Knee cartilage and menisci geometries were obtained from subjects’ magnetic resonance images (3T, GE Health Care). An EMG-assisted musculoskeletal finite element modeling workflow was used to estimate knee cartilage tissue mechanics in walking trials. Knee cartilage and menisci were modeled using a transversely isotropic poroviscoelastic material model.

Walking speed in SWS, 110%, and 120% of SWS were 1.38 m/s, 1.51 m/s, and 1.65 m/s for the young, and 1.21 m/s, 1.34 m/s and 1.46 m/s for the elderly, respectively. The maximum tensile stress in the elderly tibial cartilage was ~25%, ~33%, and ~32% lower than the young at SWS, 110%, and 120% of SWS, respectively. These preliminary results suggest that the cartilage in the elderly may not have enough stimulation even at 20% increases in walking speed, which may be one reason for tissue degeneration. To enhance these findings, further study with more subjects and different genders will investigate how age-related gait dynamics affects knee biomechanics.

Acknowledgments: Australian NHMRC Ideas Grant (APP2001734), KITECH (JE220006)

Determine the prevalence, etiologies, and risk factors of unplanned return to the OR (UROR) in adult orthopaedic trauma patients.

Retrospective review of a trauma prospective registry from 2014 – 2019 at a Level 1 academic hospital. An UROR was defined as a patient returning to OR unexpectedly following a planned definitive surgery to either readdress the presenting diagnosis or address a complication arising from the index procedure. Univariate and multivariate logistic regression was performed comparing those patients with an UROR versus those without.

A total of 1568 patients were reviewed. The rate of UROR was 9.8% (153 patients). Symptomatic implant was the leading cause of UROR (60%). Other significant UROR causes were infection (15%) and implant failure (9%). The median time between index procedure and UROR was 301 days.

For the univariate and multivariate analysis, open fracture (p< 0.05), fracture complexity (p<0.01), and weekend procedure (p< 0.01) were all associated with increased risk of UROR. All other variables were not statistically significant for any associations.

Those patients with an UROR for reasons other than symptomatic implants were more likely to have polyorthopaedic injuries (p < 0.05), ISS > 15 (p < 0.05), osteoporosis (p < 0.01), ICU status (p < 0.05), psychiatric history (p < 0.05), compartment syndrome (p < 0.05), neurovascular injury (p < 0.01), open fracture (p < 0.05), and fracture complexity (p < 0.05).

The rate of UROR in the orthopaedic trauma patient population is 10%. Most of these cases are due to implant-related issues. UROR for reasons other than symptomatic implants tend to be polytraumatized patients with higher-energy injuries, multiple complex fractures, and associated soft tissue injuries. Future focus on improved implant development and treatments for polytraumatized patients with complex fractures is warranted to decrease a relatively high UROR rate in orthopaedic trauma.

Chronic lateral ankle instability (CLAI) is treated operatively, whereas acute ligament injury is usually treated nonoperatively. Such treatments have been widely validated. Apoptosis is known to cause ligament degeneration; however, few reports have focused on the possible role of apoptosis in degeneration of ruptured lateral ankle ligaments. The aim of our study is to elucidate the apoptosis that occurs within anterior talofibular ligament (ATFL) to further validate current CLAI treatments by adducing molecular and cellular evidence.

Between March 2019 and February 2021, 50 patients were prospectively enrolled in this study. Ruptured ATFL tissues were collected from 21 CLAI patients (group C) and 17 acute ankle fracture patients (group A). Apoptotic cells were counted using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay. Western blotting for caspases 3, 7, 8, and 9 and cytochrome c, was performed to explore intrinsic and extrinsic apoptotic pathways. Immunohistochemistry was used to detect caspases 3, 7, 8, and 9 and cytochrome c, in ligament vessel endothelial cells.

More apoptotic cells were observed in group C than group A in TUNEL assay. Western blotting revealed that the apoptotic activities of group C ligaments were significantly higher than those of group A (all p < 0.001). Immunohistochemistry revealed increased expression of caspases 3, 7, 8, and 9, and cytochrome c, in group C compared to group A.

The ATFL apoptotic activities of CLAI patients were significantly higher than those of acute ankle fracture patients, as revealed biochemically and histologically. Our data further validate current CLAI treatments from a molecular and cellular perspective. Efforts should be made to reverse or prevent ATFL apoptosis in CLAI patients.

Aims

Although absorbable sutures for the repair of acute Achilles tendon rupture (ATR) have been attracting attention, the rationale for their use remains insufficient. This study prospectively compared the outcomes of absorbable and nonabsorbable sutures for the repair of acute ATR.

Aims

The association of auraptene (AUR), a 7-geranyloxycoumarin, on osteoporosis and its potential pathway was predicted by network pharmacology and confirmed in experimental osteoporotic mice.

Aim

Literature has argued for the ‘surgical personality’. Characteristics of ‘successful’ orthopaedic surgeons have also been published. The aim of the study is to explore which factors influence career choice of trauma and orthopaedics (T&O) in medical students, and whether certain personalities are drawn to T&O.

Aims

Use of videos for patient education has grown in popularity. Literature promotes the use of videos to provide clearer information to patients and families. Information to patients are often provided via leaflets. In our regional (Cwm Taf Morgannwg University Health board- CTM UHB) one stop clinic, we aimed to pilot the use of an educational video on developmental dysplasia of the hip (DDH) for parents and guardians and assess its usefulness.

Aims

The aim of this study was to compare the characteristics and outcomes of L-shaped and reverse L-shaped rotator cuff tears.

Aims

Bone metastasis ultimately occurs due to a complex multistep process, during which the interactions between cancer cells and bone microenvironment play important roles. Prior to colonization of the bone, cancer cells must succeed through a series of steps that will allow them to gain migratory and invasive properties; epithelial-to-mesenchymal transition (EMT) is known to be integral here. The aim of this study was to determine the effects of G protein subunit alpha Q (GNAQ) on the mechanisms underlying bone metastasis through EMT pathway.

Aims

The aim of this study was to compare patient-reported outcome measures (PROMs) and the Single Assessment Numerical Evaluation (SANE) score in patients treated with a volar locking plate for a distal radial fracture.

Purpose

The purpose of this study was to elucidate kinematic change according to the implant's specific femoral rotation by using orthosensor (Verasense) implant with three degrees external rotation of femoral rotation rebuilt (Genesis-II) and traditional TKA implant without rebuilt of the femoral rotation (Anthem).

Aims

Receptor activator of nuclear factor-κB ligand (RANKL) is a key molecule that is expressed in bone stromal cells and is associated with metastasis and poor prognosis in many cancers. However, cancer cells that directly express RANKL have yet to be unveiled. The current study sought to evaluate how a single subunit of G protein, guanine nucleotide-binding protein G(q) subunit alpha (GNAQ), transforms cancer cells into RANKL-expressing cancer cells.

Aims

Spinal tuberculosis (TB) remains an important concern. Although spinal TB often has sequelae such as myelopathy after treatment, the predictive factors affecting such unfavourable outcomes are not yet established. We investigated the clinical manifestations and predictors of unfavourable treatment outcomes in patients with spinal TB.

Objectives

The aim of this study was to investigate the biomechanical effect of the anterolateral ligament (ALL), anterior cruciate ligament (ACL), or both ALL and ACL on kinematics under dynamic loading conditions using dynamic simulation subject-specific knee models.

Aims

Custom flange acetabular components (CFACs) are a patient-specific option for addressing large acetabular defects at revision total hip arthroplasty (THA), but patient and implant characteristics that affect survivorship remain unknown. This study aimed to identify patient and design factors related to survivorship.

The role of unicompartmental knee arthroplasty (UKA) in spontaneous osteonecrosis of the knee (SONK) remains controversial, even though SONK usually involves only medial compartment of the knee joint. We aimed to compare the survival rate and clinical outcomes of UKA in SONK and medial compartment osteoarthritis (MOA) via a meta-analysis of previous studies. MEDLINE database in PubMed, the Embase database, and the Cochrane Library were searched up to January 2018 with keywords related to SONK and UKA. Studies were selected with predetermined inclusion criteria: (1) medial UKA as the primary procedure, (2) reporting implant survival or clinical outcomes of osteonecrosis and osteoarthritis, and (3) follow-up period greater than 1 year. Quality assessment was performed using the risk of bias assessment tool for non-randomised studies (RoBANs). A random effects model was used to estimate the pooled relative risk (RR) and standardised mean difference. The incidence of UKA revision for any reason was significantly higher in SONK than in MOA group (pooled RR = 1.83, p = 0.009). However, the risk of revision due to aseptic loosening and all- cause re-operation was not significantly different between the groups. Moreover, when stratified by the study quality, high quality studies showed similar risk of overall revision in SONK and MOA (p = 0.71). Subgroup analysis revealed worse survival of SONK, mainly related to high failure after uncemented UKA. Clinical outcomes after UKA were similar between SONK and MOA (p = 0.66). Cemented UKA has similar survival and clinical outcomes in SONK and MOA. Prospective studies designed specifically to compare the UKA outcomes in SONK and MOA are necessary.

Background

Occasionally, patients experience new or increased ankle pain following total knee arthroplasty (TKA). The aims of this study were to determine (1) how the correction of varus malalignment of the lower limb following TKA affected changes in alignment of the ankle and hindfoot, (2) the difference in changes in alignment of the ankle and hindfoot between patients with and without ankle osteoarthritis (OA), and (3) whether the rate of ankle pain and the clinical outcome following TKA differed between the 2 groups.

Background

Authors sought to determine the degree of lateral condylar hypoplasia of distal femur was related to degree of valgus malalignment of lower extremity in patients who underwent TKA. Authors also examined the relationships between degree of valgus malalignment and degree of femoral anteversion or tibial torsion.

Recently, concerns arose over the medial tibial bone resorption of a novel cobalt-chromium (CoCr) implant. This study aimed to investigate the effects of tibial component material, design, and patient factors on periprosthetic bone resorption and to determine its association with clinical outcomes after total knee arthroplasty (TKA). A total of 462 primary TKAs using five types of implants were included. To evaluate tibial periprosthetic bone resorption, we assessed radiolucent lines (RLL) and change in bone mineral density at the medial tibial condyle (BMDMT). Factors related to bone resorption were assessed using regression analysis. Clinical outcomes were also evaluated with respect to periprosthetic bone resorption. Compared to titanium (Ti) implants, CoCr implants showed a higher incidence of complete RLL (23.1% vs. 7.9% at two years post-TKA) and a greater degree of BMDMT reduction. However, there was no significant difference between the implants made of the same material. Increased medial tibial bone resorption was associated with male sex, osteoporosis, larger preoperative varus deformity, longer follow-up period, and lower body mass index. The periprosthetic bone resorption was not associated with clinical outcomes including changes in range of motion and WOMAC score. Furthermore, no cases warranted additional surgery. Periprosthetic bone resorption was associated with implant material but not with implant design. Moreover, patient factors were related to the medial tibial bone resorption post-TKA. However, the periprosthetic bone resorption was not associated with short-term clinical outcomes. We contend that researchers should incorporate integrative considerations when developing and assessing novel implants.

Purpose

We sought to determine whether there was a difference in the posterior condylar offset (PCO), posterior condylar offset ratio (PCOR) following total knee arthroplasty (TKA) with anterior referencing (AR) or posterior referencing (PR) systems. We also assessed whether the PCO and PCOR changes, as well as patient factors were related to range of motion (ROM) in each referencing system. In addition, we examined whether the improvements in clinical outcomes differed between the two referencing systems.

PEMF is currently approved by the FDA for adjunctive treatment of lumbar/cervical spine fusion and for treatment of long-bone non-unions. Soft tissues are a potential new therapeutic application for PEMF due to pre-clinical studies showing a reduction of inflammatory markers following PEMF exposure. The aim was therefore to investigate the structural/functional effects of PEMFs on tendon-to-bone and tendon-to-tendon healing in a rotator-cuff (RC) and Achilles tendon (AT) repair model, respectively. RC study: Adult male rats (n=280), underwent bi-lateral supraspinatus tendon transections with immediate repair followed by cage activity until sacrifice (4, 8, and 16 weeks). Non-controls received PEMF for 1, 3, or 6 hours daily. AT study: Male rats underwent acute, complete transection and repair of the Achilles tendon (FULL, n=144) or full thickness, partial width injury (PART, n=160) followed by immobilization for 1 week. Sacrifice was at 1, 3, and 6 weeks. Outcome measures included passive joint mechanics, gait analysis, biomechanical assessments, histological analysis of the repair site and mCT (humerus) assessment (FULL only). RC study: Significant increases in modulus, stiffness, bone mineral content and improved collagen organization was observed for the PEMF groups. No differences in joint mechanics and ambulation were observed. AT study: A decrease in stiffness and limb-loading rate was observed for the PEMF groups for the FULL groups, whereas an increase in stiffness with no change in range-of-motion was seen for the PART groups. The combined studies show that PEMF can be effective for soft tissue repair but is dependent on the location of application.

Introduction

Custom flanged acetabular components (CFAC) have been shown to be effective in treating complex acetabular reconstructions in revision total hip arthroplasty (THA). However, the specific patient factors and CFAC design characteristics that affect the overall survivorship remain unclear. Once the surgeon opts to follow this treatment pathway, numerous decisions need to be made during the pre-operative design phase and during implantation, which may influence the ultimate success of CFAC. The goal of this study was to retrospectively review the entire cohort of CFAC cases performed at a large volume institution and to identify any patient, surgeon, or design factors that may be related to the long-term survival of these prostheses.

Objective

This paper aims to analyze the kinetics of the over-ground wheel-type body weight supporting system (BWS); tendency changes of low extremity joint moment (hip, knee, ankle), 3 axis accelerations of a trunk, cadence and gait velocity as weight bearing level changes.

Purpose

Management and outcomes of fungal periprosthetic joint infection (PJI) remain unclear due to its rarity. Although two-stage exchange arthroplasty is considered a treatment of choice for its chronic features, there is no consensus for local use of antifungal agent at the 1st stage surgery. The purpose of this study was to evaluate the efficacy of antifungal-impregnated cement spacer in two-stage exchange arthroplasty against chronic fungal PJIs after total knee arthroplasty (TKA).

Aims

Joint arthroplasties may be associated with a blood loss, which necessitates transfusion. Especially, hip arthroplasties are highly associate with transfusion to compensate perioperative bleeding. Orthopaedic surgeons and patients have increasing concerns regarding complications of blood transfusions. Although various methods to reduce transfusions have been attempted in TJA, a high percentage of patients require a transfusion during and after the procedures. The purposes of this study were to evaluate the trends of the transfusion(transfusion rates, transfusion amounts, economic burden) in hip arthroplasties, using nationwide data from the National Health Insurance Service (NHIS).

Aims

The aim of this study was to compare the rate of mortality and causes of death in Korean patients who undergo surgery for a fracture of the hip, up to 11 years after the injury, with a control group from the general population.

Aims

The aim of this study was to evaluate improvements in the quality and safety of paediatric spinal surgery following the implementation of a specialist Paediatric Spinal Surgical Team (PSST) in the operating theatre.

Aims

Identifying predictors of compartment syndrome in the foot after a fracture of the calcaneus may lead to earlier diagnosis and treatment. The aim of our study was to identify any such predictors.

Most patients presenting with loss of hip motion secondary to FAI have a combination of cam and pincer morphology. In this study, we present a composite index for predicting joint ROM based on anatomic parameters derived from both the femur and acetabulaum using a single reformatted CT slice.

Computer models of the hip joint were reconstructed from CT scans of 31 patients with mixed-type FAI (Average alpha angle: 73.6±11.1°, average LCE: 38.9±7.2°). The internal rotation of the hip at impingement was measured at 90° flexion using custom software. With the joint in neutral, a single slice perpendicular to the acetabular rim was taken at the 2 o'clock position. A set of 11 femoral and acetabular parameters measured from this slice were correlated with hip ROM using stepwise logistic regression.

Three anatomic parameters provided significant discrimination of cases impinging at <15 and >15 degrees IR: femoral anteversion (28%, p=0.026), the arc of anterior femoral head sphericity (10%, p=0.040), and the LCE in the 2 o'clock plane (10%, p=0.048). This led to the following definition of the Impingement Index: 0.16*(fem version) +0.11*(ant arc)−0.17*(LCE) which correctly classified 82% of cases investigated. None of the traditional parameters (e.g. alpha angle) were significantly correlated with ROM.

Our study has identified alternative morphologic parameters that could act as strong predictors of FAI in preoperative assessments. Using this information, each patient's individual risk of impingement may be estimated, regardless of the relative contributions of deformities of the femur and the acetabulum.

Aims

The aim of this prospective study was to evaluate the intermediate-term outcomes after revision anatomical ankle ligament reconstruction augmented with suture tape for a failed modified Broström procedure.

Background

Patellofemoral complications have dwindled with contemporary total knee designs that market anatomic trochlear grooves that intend to preserve normal patella kinematics. While most reports of patellofemoral complications address patella and its replacement approach, they do not focus on shape of trochlear grooves in different prostheses [1]. The purpose of this study was to characterize 3D geometry of trochlear grooves of contemporary total knee designs (NexGen, Genesis II, Logic, and Attune) defined in terms of sulcus angle and medial-lateral offset with respect to midline of femoral component in coronal view and to compare to those of native femurs derived from 20 osteoarthritic patient CT scans.

Aims

Morton’s neuroma is common condition of the forefoot, but its aetiology remains unclear. Our aim was to evaluate the relationship between the width of the forefoot and the development of a Morton’s neuroma.

Objectives

Eukaryotic translation initiation factor 3 (eIF3) is a multi-subunit complex that plays a critical role in translation initiation. Expression levels of eIF3 subunits are elevated or decreased in various cancers, suggesting a role for eIF3 in tumorigenesis. Recent studies have shown that the expression of the eIF3b subunit is elevated in bladder and prostate cancer, and eIF3b silencing inhibited glioblastoma growth and induced cellular apoptosis. In this study, we investigated the role of eIF3b in the survival of osteosarcoma cells.

Background

Open-wedge high tibial osteotomy (OWHTO) is an operation involving proper load re-distribution in the treatment for medial uni-compartmental arthritis of the knee joint. Therefore, stable fixation is mandatory for safe healing of this additive type of osteotomy to minimize the risk of non-union and loss of correction. For stability, screws provide optimal support and anchorage of the fixator in the condylar area without risking penetration of either the articulating surface. The purpose of the study was to evaluate the screw insertion angle and orientation with an anatomical plate that is post-contoured to the surface geometry of the proximal tibia after OWHTO.

Objectives

We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model.

Introduction

Contemporary total knee systems accommodate for differential sizing between femoral and tibial components to allow surgeons to control soft tissue balancing and optimize rotation. One method some manufacturers use to allow differential sizing involves maintaining coronal articular congruency with a single radius of curvature throughout sizes while clipping the medial-lateral width, called a single coronal geometry system. Registry data show a 20% higher revision rate when the tibial component is smaller than the femur (downsizing) in the DePuy PFC system, a single coronal system, possibly from increased stresses from edge loading or varying articular congruency. We examined a different single coronal geometry knee system, Smith & Nephew Genesis II, to determine if edge loading is present in downsized tibial components by measuring area and location of deviation of the polyethylene articular surface damage.

Introduction

Numerous factors have been hypothesized as contributing to mechanically-assisted corrosion at the head-neck junction of total hip prostheses. While variables attributable to the implant and the patient are amenable to investigation, parameters describing assembly of the component parts can be difficult to determine. Nonetheless, increasing evidence suggests that the manner of intraoperative assembly of modular components plays a critical role in the fretting and corrosion of modular implants. This study was undertaken to measure the magnitude and direction of the impaction forces applied by surgeons in assembling modular head-neck junctions under operative conditions where both the access and visibility of the prosthesis may potentially compromise component fixation.

Introduction

Lateralizing the center of rotation (COR) of reverse total shoulder arthroplasty (rTSA) has the potential to increase functional outcomes of the procedure, namely adduction range of motion (ROM). However, increased torque at the bone-implant interface as a result of lateralization may provoke early implant loosening, especially in situations where two, rather than four, fixation screws are used. The aim of this study was to utilize finite element (FE) models to investigate the effects of lateralization and the number of fixation screws on micromotion and adduction ROM.

Osteoarthritic (OA) changes to the bone morphology of the proximal tibia may exhibit load transfer patterns during total knee arthroplasty not predicted in models based on normal tibias. Prior work highlighted increased bone density in transverse sections of OA knees in the proximal-most 10mm tibial cancellous bone. Little is known about coronal plane differences, which could help inform load transfer from the tibial plateau to the tibial metaphysis. Therefore, we compared the cancellous bone density in OA and cadaveric (non-OA) subjects along a common coronal plane.

This study included nine OA patients (five women, average age 59.1 ± 9.4 years) and 18 cadaver subjects (four women, average age 39.5 ± 14.4 years). Patients (eight with medial OA and one with lateral OA) received pre-operative CT scans as standard-of-care for a unicompartmental knee replacement. Cadavers were scanned at our institution and had no history of OA which was confirmed by gross inspection during dissection.

3D reconstructions of each proximal tibia were made and an ellipse was drawn on the medial and lateral plateau using a previously published method. A coronal section (Figure 1) to standardize the cohort was created using the medial ellipse center, lateral ellipse center, and the tibial shaft center 71.5mm from the tibial spine. On this section, profile lines were drawn from the medial and lateral ellipse centers, with data collected from the first subchondral bone pixel to a length of 20mm. The Hounsfield Units (HU) along each profile line was recorded for each tibia; a representative graphical distribution is shown in Figure 2. The Area Under the Curve (AUC) was calculated for the medial and lateral sides, which loosely described the stiffness profile through the region of interest. To determine differences between the medial and lateral subchondral bone density, the ratio AUC[medial] / AUC[lateral] was compared between the OA and cadaver cohorts using a two-sample t-test. Data from the sole lateral OA patient was mirror-imaged to be included in the OA cohort.

The majority of the OA patients appeared to have higher subchondral bone density on the affected side. Figure 3 compares the medial and laterals sides of each group using the AUC ratio method described above. For the cadaver group the AUC was 1.2 +/− 0.22, with a median of 1.1 [0.9 1.6], smaller than the mean AUC for the OA group, which was 1.4 +/− 0.39, with a median of 1.6 [0.93 2.1]. The p-value was 0.06.

The increased density observed in OA patients is consistent with asymmetric loading towards the affected plateau, resulting in localized remodeling of cancellous bone from the epiphysis to metaphysis. From the coronal plane, bone was often observed in OA patients bridging the medial plateau to the metaphyseal cortex. Although the cadaver subjects were normal from history and gross inspection, some subjects exhibited early bone density changes consistent with OA. Future work looks to review more OA scans, extend the work to the distal femur, and convert the HU values to bone elastic moduli for use in finite element modelling.

Aims

We hypothesised that the synovial white blood cell (WBC) count in patients with a late periprosthetic joint infection (PJI) of the hip would depend on the duration of a patient’s symptoms, and that the optimal diagnostic threshold would also depend on this period of time.

Introduction

Arthroplasties of hip and knee are associated with blood loss, which may lead to adverse patient outcome. Jehovah's Witnesses do not accept blood transfusion. Performing arthroplasties in Witness patients without transfusion has been a matter of concern. We developed a protocol, which avoids transfusion in arthroplasties of Witness patients, and evaluated the feasibility and safety of the protocol.

Introduction

Deformity of knee joint causes deviation of mechanical axis in the coronal plane, and the mechanical axis deviation also could adversely affect biomechanics of the ankle joint as well as the knee joint. Particularly, most of the patients undergoing total knee arthroplasty (TKA) have significant preoperative varus malalignment which would be corrected after TKA, the patients also may have significant changes of ankle joint characteristics after the surgery. This study aimed 1) to examine the prevalence of coexisting ankle osteoarthritis (OA) in the patients undergoing TKA due to varus knee OA and to determine whether the patients with coexisting ankle OA have more varus malalignment, and 2) to evaluate the changes of radiographic parameters for ankle joint before and 4 years after TKA.

The purpose of this study was to evaluate the Mid-term results (minimum 5 year) of the use of 36 mm metallic femoral head coupled with 1st generation HXLPE in patients with the age of less than or equal to 50 years-old. This retrospective study included 31 cases sustained hip pain needed Total Hip Replace Arthroplasty. We used cementless stem(FMT, Zimmer, Warsaw, Indiana) at 28 cases and cement stem(Versys, Zimmer, Warsaw, Indiana) at 3 cases. We used Trilogy (Zimmer, Warsaw, Indiana) in all cases as an acetabular cup and Longevity (Zimmer, Warsaw, Indiana) in all cases as a HXLPE. Mean acetabular cup size was 52.88mm. Mean HXLPE liner thickness at 45o was 6.18mm [Fig.1]. Mean Harris hip score was 91(86–96) and all cases obtained more than 15 scores in Merle d'Aubigne and postel method at recent follow ups. All femoral stem showed stable fixation status. Mean acetabular cup Inclination was 50.6o and Anteversion was 23.1o. During follow ups, there was no complication including dislocation, osteolysis, infection and plastic fracture. Bedding-in wear rate was 0.079±0.034mm/yr. And Steady- state was 0.043±0.016mm/yr. In vitro study, 1stgeneration HXLPE showed negative mechanical property changes due to high dose radiation and remelting. So, concerns remained in using HXLPE to active patients. But we checked a good results in terms of functional scores and wear rates. And, there was no major complication during minimal 5 years check ups. So, the authors thought THRA with 36mm- metallic heads on 1st-Generation Highly Cross-linked Polyethylene as a bearing surface could be a good option in less than or equal to 50 years patients.

Introduction

Even a number of studies have reported clinical outcomes after revision total knee arthroplasty (revision TKA), little information is still available on whether outcomes of patients undergoing a revision TKA as a second stage procedure because of infected TKA are poorer than those of the patients undergoing a single-stage revision TKA because of non-infectious causes. In addition, use of various revision prostheses in most previous studies may limit solid interpretation of the outcomes after revision TKA. This study sought to determine whether outcomes in patients undergoing revision TKA due to infected TKA would be different from those in patients undergoing revision TKA due to non-infectious causes.

Introduction

Open wedge high tibial osteotomy (OWHTO) is an operation by the proper load re-distribution in the treatment for medial uni-compartmental arthritis of the knee joint. However, for the proper load re-distribution, stable fixation is mandatory. For the stable fixation, plate should be contoured to the bony surface and screws should be inserted from the central area of the medial side to the hinge area of the lateral side in the proximal fragment because most failures occur at the relatively lesser supported lateral hinge area. Therefore, the purpose of this study was to evaluate the screw insertion angle and orientation that is inserted to the direction of the lateral hinge with an anatomical plate that is post-contoured with a surface geometry of the proximal tibia after the OWHTO. The hypothesis of this study was that the position and orientation would be different according to the correction degree (median value 10 mm) and surgical technique (uni-planar vs bi-planar).

Introduction

Total knee arthroplasty (TKA) is a proven treatment method for advanced knee arthritis in terms of pain relief, function restoration, and quality-of-life improvement. The TKA use has increased significantly over the past decade and the growing rate is more prominent in Asian countries. Thus, the revision TKA may also increase in recent days, which represents a burden to the national health care system. To the best of our knowledge, little information is currently available regarding the incidence and related factors of revision TKA in Asian countries on the basis of nationwide database. This study sought to find the incidence of revision TKA and related factors in South Korea using national database from 2007 to 2012.

Introduction

3-D Printing with direct metal tooling (DMT) technology was innovatively introduced in the field of surface treatment of prosthesis to improve, moreover to overcome the problems of plasma spray, hopefully resulting in opening the possibility of another page of coating technology. We presumed such modification on the surface of Co-Cr alloy by DMT would improve the ability of Co-Cr alloys to osseointegrate.

Introduction

We investigated the incidence of venous thromboembolism (VTE) and pulmonary embolism (PE) after total knee arthroplasty (TKA) and assessed the efficacy and complications of three different chemical prophylactic regimens.

Introduction

The purpose of this study was to evaluate the mid-term clinical and radiological results in patients who were managed by double metal augmentations in proximal tibial uncontained bony defects undergoing primary or revision total knee arthroplasty

We compared the ceiling effects of two patient-rating scores, the Disability of the Arm, Shoulder and Hand (DASH) and Patient-Rated Wrist Evaluation (PRWE), and a physician-rating score, the Modified Mayo Wrist Score (MMWS) in assessing the outcome of surgical treatment of an unstable distal radial fracture. A total of 77 women with a mean age of 64.2 years (50 to 88) who underwent fixation using a volar locking plate for an unstable distal radial fracture between 2011 and 2013 were enrolled in this study. All completed the DASH and PRWE questionnaires one year post-operatively and were assessed using the MMWS by the senior author. The ceiling effects in the outcome data assessed for each score were estimated.

The data assessed with both patient-rating scores, the DASH and PRWE, showed substantial ceiling effects, whereas the data assessed with MMWS showed no ceiling effect.

Researchers should be aware of a possible ceiling effect in the assessment of the outcome of the surgical treatment of distal radial fractures using patient-rating scores. It could also increase the likelihood of a type II error.

Cite this article: Bone Joint J 2015;97-B:1651–6.

The purpose of this study was to evaluate the change in sagittal tibiotalar alignment after total ankle arthroplasty (TAA) for osteoarthritis and to investigate factors affecting the restoration of alignment.

This retrospective study included 119 patients (120 ankles) who underwent three component TAA using the Hintegra prosthesis. A total of 63 ankles had anterior displacement of the talus before surgery (group A), 49 had alignment in the normal range (group B), and eight had posterior displacement of the talus (group C). Ankles in group A were further sub-divided into those in whom normal alignment was restored following TAA (41 ankles) and those with persistent displacement (22 ankles). Radiographic and clinical results were assessed.

Pre-operatively, the alignment in group A was significantly more varus than that in group B, and the posterior slope of the tibial plafond was greater (p < 0.01 in both cases). The posterior slope of the tibial component was strongly associated with restoration of alignment: ankles in which the alignment was restored had significantly less posterior slope (p < 0.001).

An anteriorly translated talus was restored to a normal position after TAA in most patients. We suggest that surgeons performing TAA using the Hintegra prosthesis should aim to insert the tibial component at close to 90° relative to the axis of the tibia, hence reducing posterior soft-tissue tension and allowing restoration of normal tibiotalar alignment following surgery.

Cite this article: Bone Joint J 2015;97-B:1525–32.

We performed a retrospective study to determine the effect of osteoporosis on the functional outcome of osteoporotic distal radial fractures treated with a volar locking plate. Between 2009 and 2012 a total of 90 postmenopausal women with an unstable fracture of the distal radius treated with a volar locking plate were studied. Changes in the radiological parameters of 51 patients with osteoporosis (group 1, mean age 66.9, mean T-score –3.16 (sd 0.56)) were not significantly different from those in 39 patients without osteoporosis (group 2, mean age 61.1, mean T-score –1.72 (sd 0.57)). The mean Disabilities of the Arm, Shoulder and Hand (DASH) score at final follow-up was 11.5 (sd 12.2) in group 1 and 10.5 (sd 13.25) in group 2. The mean modified Mayo wrist score at final follow-up was 79.0 (sd 14.04) in group 1 and 82.6 (sd 13.1) in group 2. However, this difference was not statistically significant (p = 0.35 for DASH score, p = 0.2 for modified Mayo wrist score). Univariable and multivariable logistic regression analysis showed that only the step-off of the radiocarpal joint was related to both a poor DASH and modified Mayo wrist score. Pearson’s correlation coefficient showed a weak negative relationship only between the T-score and the change in volar tilt (intraclass coefficient –0.26, p = 0.02).

We found that osteoporosis does not have a negative effect on the functional outcome and additional analysis did not show a correlation between T-score and outcome.

Cite this article: Bone Joint J 2015;97-B:229–34.

We compared the clinical and radiographic results of total ankle replacement (TAR) performed in non-diabetic and diabetic patients. We identified 173 patients who underwent unilateral TAR between 2004 and 2011 with a minimum of two years’ follow-up. There were 88 male (50.9%) and 85 female (49.1%) patients with a mean age of 66 years (sd 7.9, 43 to 84). There were 43 diabetic patients, including 25 with controlled diabetes and 18 with uncontrolled diabetes, and 130 non-diabetic patients. The clinical data which were analysed included the Ankle Osteoarthritis Scale (AOS) and the American Orthopaedic Foot and Ankle Society (AOFAS) scores, as well the incidence of peri-operative complications.

The mean AOS and AOFAS scores were significantly better in the non-diabetic group (p = 0.018 and p = 0.038, respectively). In all, nine TARs (21%) in the diabetic group had clinical failure at a mean follow-up of five years (24 to 109), which was significantly higher than the rate of failure of 15 (11.6%) in the non-diabetic group (p = 0.004). The uncontrolled diabetic subgroup had a significantly poorer outcome than the non-diabetic group (p = 0.02), and a higher rate of delayed wound healing.

The incidence of early-onset osteolysis was higher in the diabetic group than in the non-diabetic group (p = 0.02). These results suggest that diabetes mellitus, especially with poor glycaemic control, negatively affects the short- to mid-term outcome after TAR.

Cite this article: Bone Joint J 2014;96-B:1674–80.

Previous studies support the important role of vascular endothelial growth factor (VEGF) and syndecan-4 in the pathogenesis of osteoarthritis (OA). Both VEGF and syndecan-4 are expressed by chondrocytes and both are involved in the regulation of matrix metalloproteinase-3, resulting in the activation of aggrecanase II (ADAMTS-5), which is essential in the pathogenesis of OA. However, the relationship between VEGF and syndecan-4 has not been established. As a pilot study, we assayed the expression of VEGF and syndecan-4 in cartilage samples and cultured chondrocytes from osteoarthritic knee joints and analysed the relationship between these two factors.

Specimens were collected from 21 female patients (29 knees) who underwent total knee replacement due to severe medial OA of the knee (Kellgren–Lawrence grade 4). Articular cartilage samples, obtained from bone and cartilage excised during surgery, were analysed and used for chondrocyte culture. We found that the levels of expression of VEGF and syndecan-4 mRNA did not differ significantly between medial femoral cartilage with severe degenerative changes and lateral femoral cartilage that appeared grossly normal (p = 0.443 and 0.622, respectively). Likewise, the levels of expression of VEGF and syndecan-4 mRNA were similar in cultured chondrocytes from medial and lateral femoral cartilage. The levels of expression of VEGF and syndecan-4 mRNAs were significantly and positively correlated in cartilage explant (r = 0.601, p = 0.003) but not in cultured chondrocytes. These results suggest that there is a close relationship between VEGF and syndecan-4 in the cartilage of patients with OA. Further studies are needed to determine the exact pathway by which these two factors interact in the pathogenesis of OA.

Cite this article: Bone Joint J 2014;96-B:1319–24.

Monostotic fibrous dysplasia of the proximal femur has a variable clinical course, despite its reported limited tendency to progress.

We investigated the natural history and predisposing factors for progression of dysplasia in a group of 76 patients with a mean follow-up of 8.5 years (2.0 to 15.2). Of these, 31 (41%) presented with an asymptomatic incidental lesion while 45 (59%) presented with pain or a pathological fracture. A group of 23 patients (30%) underwent early operative treatment for pain (19: 25%) or pathological fracture (4: 5%).

Of the 53 patients who were initially treated non-operatively, 45 (85%) remained asymptomatic but eight (15%) needed surgery because of pain or fracture. The progression-free survival of the observation group was 81% (sd 6.4%) at five-years follow-up. An initial presentation of pain (p < 0.001), a limp (p < 0.001), radiological evidence of microfracture (p = 0.001) and younger age (< 17 years) (p = 0.016) were significant predisposing factors for disease progression.

The risk of experiencing pain or pathological fracture is considerable in monostotic fibrous dysplasia of the proximal femur. Patients presenting with pain, a limp or radiological evidence of microfracture have a high chance of needing surgical treatment.

Cite this article: Bone Joint J 2014;96-B:673–6.

Introduction:

Whole blood metal ion level and clinical outcomes of ceramic-on-metal bearing were comparable to ceramic-on-ceramic THA in this prospective randomized controlled trial.

Purpose:

To investigate treatment patterns and efficacy of postoperative strong opioids in patients who underwent total knee arthroplasty (TKA) in Korea

Retrieval analysis has been valuable in the assessment of in-vivo surface damage of orthopedic devices. Historically, subjective techniques were used to grade damage on the implant's surface. Microscopy improved the ability to localize and quantify damage, but cannot measure volumetric wear due to this damage. Laser scanning provides volumetric wear, but lacks image data. Recent techniques superimpose image data on laser scan data (photorendering) and combine the strengths of both methods. Our goal is to use such methods to improve our damage assessment and potentially correlate this assessment to volumetric wear.

This project focused on two areas: image-stitching and photorendering. Image-stitching registers multiple images into large-scale high-resolution composites. Six total disc replacement components were imaged with a digital microscope (Moticam 2, Motic). Three sets were taken of each component: a single template at 10x zoom (1×1), a 4-image composite at 18x zoom (2×2), and a 9-image composite at 18x zoom (3×3). The 2×2 and 3×3 sets were image-stitched to resemble their template counterpart. Measurement error was defined using common pixels identified between the composite and template images for comparison with a semi-automated feature detection algorithm (Figure 1).

For photorendering, a pilot study was performed on a single retrieved tibial bearing. The component was imaged with a digital microscope (VHX-2000, Keyence) under a 3D image-stitching setting, providing a high-resolution photo embedded with height values. MATLAB was used to convert the image into a photo-rendered point cloud approximating the surfaces. The component was then laser scanned, creating a 3D point cloud with resolution 0.127 mm. The photo-rendered point cloud data was registered to the laser scan data using an iterative closest point algorithm (Geomagic Studio, Geomagic).

An analysis of all composite images showed a mean error of 0.221 mm. Figure 2 compares regions of images for the template, 2×2, and 3×3 composites. Zooming in shows the effect of the increased resolution contained in the composite. The 2×2 and 3×3 composites had mean errors of 0.231 mm and 0.209 mm, respectively; these were not significantly different. Comparisons among image types showed that components with less features exhibited larger errors during image-stitching. Figure 3 shows images resulting from each step of the photorendering process. The final image of the figure shows a qualitative result of our ability to photorender the tibial bearing surface of the component.

While combining microscopy and laser scan data works anecdotally, further analyses must be performed to assure the robustness of the technique. The digital microscope's embedded image-stitching software is limited in its maximum field of view; we look to extend this by taking multiple scans and using in-house software to generate a composite of a whole implant. The improved resolution provided by microscopy offer an opportunity to automate damage assessment, yielding damage mapped images which can also be overlaid on laser scan data. This may provide a means to better quantify observed damage and yield meaningful correlations with volumetric loss due to wear.

Lateralizing the center of rotation in reverse shoulder arthroplasty has been the subject of renewed interest due to complications associated with medialized center of rotation implants. Benefits of lateralization include: increased joint stability, decreased incidence of scapular notching, increased range of motion, and cosmetic appeal. However, lateralization may be associated with increased risk of glenoid loosening, which may result from the increased shear forces and the bending stresses that manifest at the bone-implant interface. To address glenoid loosening in reverse implants with lateralized joint centers, recent studies have focused on testing and improving implant fixation. However, these studies use loads derived from literature specific to subjects with normal anatomy. The aim of this study is to characterize how joint center lateralization affects the loading in reverse shoulder arthroplasty.

Using an established computational shoulder model that describes the geometry of a commercial reverse prosthesis (DELTA® III, DePuy), motion in abduction, scapular plane elevation, and forward flexion was simulated. The simulations were run for five progressively lateralized centers of rotation: −5, 0, +5, +10, and +15 mm (Figure 1). The model was modified to simulate a full thickness rotator cuff tear, where all cuff musculature except Teres Minor were excluded, to reflect the clinical indication for reverse shoulder arthroplasty on cuff tear arthropathy patients. To analyze the joint contact forces, the resultant glenohumeral force was decomposed into compression, anterior-posterior shear, and superior-inferior shear on the glenoid.

Joint center lateralization was found to affect the glenohumeral joint contact forces and glenoid loads increased by up to 18% when the center was lateralized from −5 mm to +15 mm. Compressive forces were found to be more sensitive to lateralization in abduction, while changes in shear forces were more affected in forward flexion and scapular plane abduction. On average, the superior shear component showed the largest increases due to lateralization (up to a 21% increase), while the anterior-posterior shear component showed larger changes than those of compression, except in the most lateralized center position (Figure 2).

The higher joint loads in the lateralized joint centers reflect a shortening of the Deltoid muscle moment arms (Figure 3), since the muscle needs to exert more force to provide the desired motions. The additional shear forces generated by the lateralization may increase the risk of the ‘rocking-horse’ effect. Together with the lateralized joint center, this creates an additional bending stress at the bone-implant interface that puts the implant at further risk of loosening (Figure 1). Current studies on implant fixation tend to use loads in compression and superior shear that exceed the forces seen in this study but have not investigated anterior-posterior shear loads. Our data support that loading in anterior-posterior direction can be significant. Using inappropriate loads to design fixation may result in excessive loss of bone stock and/or unforeseen implant loosening. The implication is that future studies may be performed using this more relevant data set to navigate the tradeoff between fixation and bone conservation.

In a retrospective study we compared 32 HINTEGRA total ankle replacements (TARs) and 35 Mobility TARs performed between July 2005 and May 2010, with a minimum follow-up of two years. The mean follow-up for the HINTEGRA group was 53 months (24 to 76) and for the Mobility group was 34 months (24 to 45). All procedures were performed by a single surgeon.

There was no significant difference between the two groups with regard to the mean AOFAS score, visual analogue score for pain or range of movement of the ankle at the latest follow-up. Most radiological measurements did not differ significantly between the two groups. However, the most common grade of heterotopic ossification (HO) was grade 3 in the HINTEGRA group (10 of 13 TARs, 76.9%) and grade 2 in the Mobility group (four of seven TARs, 57.1%) (p = 0.025). Although HO was more frequent in the HINTEGRA group (40.6%) than in the Mobility group (20.0%), this was not statistically significant (p = 0.065).The difference in peri-operative complications between the two groups was not significant, but intra-operative medial malleolar fractures occurred in four (11.4%) in the Mobility group; four (12.5%) in the HINTEGRA group and one TAR (2.9%) in the Mobility group failed (p = 0.185).

Cite this article: Bone Joint J 2013;95-B:1075–82.

The purpose of this study was to compare the outcome and complications of endoscopic versus open release for the treatment of de Quervain’s tenosynovitis. Patients with this condition were randomised to undergo either endoscopic (n = 27) or open release (n = 25). Visual Analogue Scale (VAS) pain and Disabilities of Arm, Shoulder, and Hand (DASH) scores were measured at 12 and 24 weeks after surgery. Scar satisfaction was measured using a VAS scale. The mean pain and DASH scores improved significantly at 12 weeks and 24 weeks (p <  0.001) in both groups. The scores were marginally lower in the endoscopic group compared to the open group at 12 weeks (p = 0.012 and p = 0.002, respectively); however, only the DASH score showed a clinically important difference. There were no differences between the groups at 24 weeks. The mean VAS scar satisfaction score was higher in the endoscopic group at 24 weeks (p < 0.001). Transient superficial radial nerve injury occurred in three patients in the endoscopic group compared with nine in the open release group (p = 0.033).

We conclude that endoscopic release for de Quervain’s tenosynovitis seems to provide earlier improvement after surgery, with fewer superficial radial nerve complications and greater scar satisfaction, when compared with open release.

Cite this article: Bone Joint J 2013;95-B:947–51.

We reviewed 91 patients (103 feet) who underwent a Ludloff osteotomy combined with additional procedures. According to the combined procedures performed, patients were divided into Group I (31 feet; first web space release), Group II (35 feet; Akin osteotomy and trans-articular release), or Group III (37 feet; Akin osteotomy, supplementary axial Kirschner (K-) wire fixation, and trans-articular release). Each group was then further subdivided into severe and moderate deformities.

The mean hallux valgus angle correction of Group II was significantly greater than that of Group I (p = 0.001). The mean intermetatarsal angle correction of Group III was significantly greater than that of Group II (p < 0.001). In severe deformities, post-operative incongruity of the first metatarsophalangeal joint was least common in Group I (p = 0.026). Akin osteotomy significantly increased correction of the hallux valgus angle, while a supplementary K-wire significantly reduced the later loss of intermetatarsal angle correction. First web space release can be recommended for severe deformity. Additionally, K-wire fixation (odds ratio (OR) 5.05 (95% confidence interval (CI) 1.21 to 24.39); p = 0.032) and the pre-operative hallux valgus angle (OR 2.20 (95% CI 1.11 to 4.73); p = 0.001) were shown to be factors affecting recurrence of hallux valgus after Ludloff osteotomy.

Cite this article: Bone Joint J 2013;95-B:803–8.

Objectives

To examine patient mortality, implant survivorship, and complication profiles of proximal femoral replacement (PFR) as compared to revision total hip arthroplasty (REV) or open reduction internal fixation (ORIF) in the treatment of acute periprosthetic fractures of the proximal femur.

Melorheostosis is a very rare mesenchymal dysplasia of bone, characterized by sclerosing hyper-pigmentation appearances on the bone, may involve the adjacent soft tissues and lead to joint pain, limitation of joint motion and stiffness as a result of abnormal ossifications and soft tissue contractures, due to periarticular fibrosis. It is well known to tend to affect only one limb, but multifocal involvement, such as multiple limbs, spine and rib, has been extremely rarely reported. A variety of treatment options have been tried so far, none being specific surgical treatments.

Here we present a case of a 43-year-old man who sustained melorheostosis with multifocal involvement including the axial skeleton and a whole entire lower limb. He had painful swelling of his left lower limb and mainly complained of difficulty walking due to severe hip pain and knee stiffness, which persisted for 20 years and was aggravated during the last 5 years. Total hip arthropasty [Fig. 1] was done first, and then total knee arthroplasty [Fig. 2, 3] was performed. During operation, there were difficulties in bone cutting and implant insertion due to mixed pattern of hard sclerotic portion and osteoporotic portion despite complete synovectomy and sufficient soft tissue release. He was eventually free of pain during walking and able to walk without a crutch and joint motion of hip and knee was substantially improved after surgery.

We found that hip pain and contracture due to osteoarthritis and knee contracture secondary to multifocal melorheostosis could be successfully treated by total hip and knee arthroplasty. To the best of our knowledge, this is the first reporting the total joint arthroplasty performed in the patients with multifocal melorheostosis.

Introduction

While shoulder elevation can be reliably restored following reverse total shoulder arthroplasty (RTSA), patients may experience a loss of internal and external rotation. Several recent studies have investigated scapular notching and have made suggestions regarding glenosphere placement in order to minimize its occurrence. However, very few studies have looked at how changes in glenosphere placement in RTSA affect internal and external rotation. The purpose of this study was to determine the effect of glenosphere position on internal and external rotation range of motion at various degrees of scaption following RTSA. We hypothesized that alteration in glenosphere position will affect the amount of impingement-free internal and external rotation.

We report the incidence and intensity of persistent pain in patients with an otherwise uncomplicated total ankle replacement (TAR). Arthroscopic debridement was performed in selected cases and the clinical outcome was analysed.

Among 120 uncomplicated TARs, there was persistent pain with a mean visual analogue scale (VAS) of 2.7 (0 to 8). The intensity of pain decreased in 115 ankles (95.8%). Exercise or walking for more than 30 minutes was the most common aggravating factor (62 ankles, 68.1%). The character of the pain was most commonly described as dull (50 ankles, 54.9%) and located on the medial aspect of the joint (43 ankles, 47.3%).

A total of seven ankles (5.8%) underwent subsequent arthroscopy. These patients had local symptoms and a VAS for pain ≥ 7 on exertion. Impingement with fibrosis and synovitis was confirmed. After debridement, the median VAS decreased from 7 to 3 and six patients were satisfied. The median VAS for pain and the American Orthopaedic Foot and Ankle Society score of the ankles after debridement was similar to that of the uncomplicated TARs (p = 0.496 and p = 0.066, respectively).

Although TAR reduces the intensity of pain, residual pain is not infrequent even in otherwise uncomplicated TARs and soft-tissue impingement is the possible cause.

Cite this article: Bone Joint J 2013;95-B:378–83.

Reverse total shoulder replacement (RTSR) depends on adequate deltoid function for a successful outcome. However, the anterior deltoid and/or axillary nerve may be damaged due to prior procedures or injury. The purpose of this study was to determine the compensatory muscle forces required for scapular plane elevation following RTSR when the anterior deltoid is deficient. The soft tissues were removed from six cadaver shoulders, except for tendon attachments. After implantation of the RTSR, the shoulders were mounted on a custom-made shoulder simulator to determine the mean force in each muscle required to achieve 30° and 60° of scapular plane elevation. Two conditions were tested: 1) Control with an absent supraspinatus and infraspinatus; and 2) Control with anterior deltoid deficiency. Anterior deltoid deficiency resulted in a mean increase of 195% in subscapularis force at 30° when compared with the control (p = 0.02). At 60°, the subscapularis force increased a mean of 82% (p < 0.001) and the middle deltoid force increased a mean of 26% (p = 0.04).

Scapular plane elevation may still be possible following an RTSR in the setting of anterior deltoid deficiency. When the anterior deltoid is deficient, there is a compensatory increase in the force required by the subscapularis and middle deltoid. Attempts to preserve the subscapularis, if present, might maximise post-operative function.

The treatment of very distal tibial fractures and pilon fractures is difficult. There is a wide variation in the severity of injury and the options for surgical management. Plates and external fixation each have their advantages. This retrospective study looks at complications and technical tips for anterolateral plating.

35 consecutive distal tibial platings were evaluated. The AO classification for each fracture was determined and any patient factors affecting outcome. Outcome variables included time to radiological union, infection rate, wound breakdown rate, and joint movement after treatment.

There were 32 anterolateral platings and 3 medial platings. The union rate was 95%. There were two deep infections which required surgical treatment. There were two wound breakdowns, one of which required plastic surgical intervention. Two patients had prominent metalwork, requiring removal. Other complications included deep peroneal nerve palsy, stiffness, and vascular compromise. The complication rates were lower for surgeons operating more frequently on these fractures. Two patients subsequently required bone transport and one required an amputation.

The complication rate found was similar to that reported in the literature. The few complications were however very significant for the patient and also for the surgeon as they required bone transport. Complications other than infection occurred in the few cases performed by surgeons low on their learning curve. We present technical tips for surgery. The presence of callus only after mobilisation indicates that union is slow.

Anterolateral plating is a viable option for distal tibial fractures, especially 43B fractures. There is a learning curve associated with their use. Complication rates are low overall, but significant consequences can accompany complications. As an alternative to external fixation, distal locking plates are not a pain free option for the surgeon, as well as for the patient.

This study evaluates factors related to myelopathic symptoms in patients with ossification of the posterior longitudinal ligament (OPLL). A total of 87 patients with OPLL were included. Of these, 53 (Group I) had no symptoms or presented with neck pain and radiculopathy and 34 (Group II) had myelopathic symptoms. Gender, age, and history of trauma were evaluated in the two groups. The range of movement of the cervical spine was measured using plain radiographs. The number of involved segments, type of OPLL, and maximal compression ratio were analysed using CT and signal change in the spinal cord was evaluated using MRI.

The patients’ age was found to be significant (p = 0.001). No difference was found between gender and the range of movement in the two groups. The maximum compression of the spinal canal showed a difference (p = 0.03). The signal change of the spinal cord was different between the two groups. In patients with OPLL of the cervical spine, myelopathic symptoms are not related to the range of movement or the number of involved segments.

This study evaluated the effect of limb lengthening on longitudinal growth in patients with achondroplasia. Growth of the lower extremity was assessed retrospectively by serial radiographs in 35 skeletally immature patients with achondroplasia who underwent bilateral limb lengthening (Group 1), and in 12 skeletally immature patients with achondroplasia who did not (Group 2). In Group 1, 23 patients underwent only tibial lengthening (Group 1a) and 12 patients underwent tibial and femoral lengthening sequentially (Group 1b).

The mean lengthening in the tibia was 9.2 cm (59.5%) in Group 1a, and 9.0 cm (58.2%) in the tibia and 10.2 cm (54.3%) in the femur in Group 1b. The mean follow-up was 9.3 years (8.6 to 10.3). The final mean total length of lower extremity in Group 1a was 526.6 mm (501.3 to 552.9) at the time of skeletal maturity and 610.1 mm (577.6 to 638.6) in Group 1b, compared with 457.0 mm (411.7 to 502.3) in Group 2. However, the mean actual length, representing the length solely grown from the physis without the length of distraction, showed that there was a significant disturbance of growth after limb lengthening. In Group 1a, a mean decrease of 22.4 mm (21.3 to 23.1) (4.9%) was observed in the actual limb length when compared with Group 2, and a greater mean decrease of 38.9 mm (37.2 to 40.8) (8.5%) was observed in Group 1b when compared with Group 2 at skeletal maturity.

In Group 1, the mean actual limb length was 16.5 mm (15.8 to 17.2) (3.6%) shorter in Group 1b when compared with Group 1a at the time of skeletal maturity. Premature physeal closure was seen mostly in the proximal tibia and the distal femur with relative preservation of proximal femur and distal tibia.

We suggest that significant disturbance of growth can occur after extensive limb lengthening in patients with achondroplasia, and therefore, this should be included in pre-operative counselling of these patients and their parents.

Introduction

Alumina ceramic-on-highly cross-linked polyethylene bearings (Al-on-X-linked PE) are attractive because of the potential for reduced wear, osteolysis and loosening of the component. The purpose of this study was to evaluate the clinical and radiographic outcomes of cementless total hip arthroplasties (THAs) using an Al-on-X-linked PE bearing and to determine the rates of osteolysis using radiographs and computer tomographic (CT) scans in young patients with osteonecrosis of femoral head.

We investigated the clinical response to arthroscopic synovectomy in patients with undifferentiated chronic monoarthritis (UCMA) of the wrist. Arthroscopic synovectomy was performed on 20 wrists in 20 patients with UCMA of the wrist who had not responded to non-steroidal anti-inflammatory drugs. The mean duration of symptoms at the time of surgery was 4.3 months (3 to 7) and the mean follow-up was 51.8 months (24 to 94). Inflamed synovium was completely removed from the radiocarpal, midcarpal and distal radioulnar joints using more portals than normal. After surgery, nine patients had early remission of synovitis and 11 with uncontrolled synovitis received antirheumatic medication. Overall, there was significant improvement in terms of pain relief, range of movement and Mayo score. Radiological deterioration was seen in five patients who were diagnosed as having rheumatoid arthritis during the follow-up period. Lymphoid follicles and severe lymphocyte infiltration were seen more often in synovial biopsies from patients with uncontrolled synovitis.

These results suggest that arthroscopic synovectomy provides pain relief and functional improvement, and allows rapid resolution of synovitis in about half of patients with UCMA of the wrist.

Lengthening of the humerus is now an established technique. We compared the complications of humeral lengthening with those of femoral lengthening and investigated whether or not the callus formation in the humerus proceeds at a higher rate than that in the femur. A total of 24 humeral and 24 femoral lengthenings were performed on 12 patients with achondroplasia. We measured the pixel value ratio (PVR) of the lengthened area on radiographs and each radiograph was analysed for the shape, type and density of the callus. The quality of life (QOL) of the patients after humeral lengthening was compared with that prior to surgery. The complication rate per segment of humerus and femur was 0.87% and 1.37%, respectively. In the humerus the PVR was significantly higher than that of the femur. Lower limbs were associated with an increased incidence of concave, lateral and central callus shapes. Humeral lengthening had a lower complication rate than lower-limb lengthening, and QOL increased significantly after humeral lengthening. Callus formation in the humerus during the distraction period proceeded at a significantly higher rate than that in the femur.

These findings indicate that humeral lengthening has an important role in the management of patients with achondroplasia.

We evaluated the incidence of heterotopic ossification following total ankle replacement to determine whether the degree of ossification was associated with the clinical outcome. We evaluated 90 ankles in 81 consecutive patients who underwent total ankle replacement, and heterotopic ossification was assessed according to proportional involvement of the ankle joint. Correlation analysis was used to investigate the association between heterotopic ossification and outcome.

No significant association was found between the formation of heterotopic ossification and the clinical outcome. The degree of heterotopic ossification in the posterior ankle joint was not significantly correlated with posterior ankle pain (p = 0.929), the American Orthopaedic Foot and Ankle Society score (p = 0.454) or range of movement (p = 0.283).

This study indicates that caution should be observed in attributing symptoms and functional limitation to the presence of heterotopic ossification in the posterior ankle joint when considering excision of heterotopic bone after total ankle replacement.

Bone defects are occasionally encountered during primary total knee replacement (TKR) and cause difficulty in establishing a stable well-aligned bone-implant interface. Between March 1999 and November 2005, 59 knees in 43 patients underwent primary TKR with a metal block augmentation for tibial bone deficiency. In all, six patients (eight knees) died less than four years post-operatively, and four patients (five knees) were lost to follow-up leaving 46 knees in 33 patients available for review at a mean of 78.6 months (62 to 129). The clinical results obtained, including range of movement, American Knee Society and Oxford knee scores, and the Western Ontario and McMaster Universities osteoarthritis index, were good to excellent, with no failures. Radiolucent lines at the block-cement-bone interface were noted in five knees (11%) during the first post-operative year, but these did not progress.

Modular rectangular metal augmentation for tibial bone deficiency is a useful option. No deterioration of the block-prosthesis or block-cement-bone interface was seen at minimum of five years follow-up.

In conventional high tibial osteotomy it is difficult to obtain the ideal correction angle consistently and there is high variability of postoperative alignment. We assessed the reliability, accuracy and variability of closed wedge high tibial osteotomy using computer-assisted surgery compared to the conventional technique. Fifty closed wedge HTO procedures were performed and analysed between July 2005 and July 2006, using the CT-free navigation system(Vector Vision^® version 1.1, Brain-LAB, Heimstetten, Germany) for medial compartment osteoarthritis of the knee and fifty knee operations using conventional closed-wedge HTO, performed between 1994 and 2006, were retrospectively reviewed as a control group. The mean age was 59.4 years for the navigation group and 60.7 years for the conventional group. In the navigation group, the mean mechanical axis (MA) before osteotomy was varus 8.2°, and the mean MA after the fixation was valgus 3.6°. On the radiographs, the mean preoperative MA was varus 7.3°, and the mean postoperative MA was valgus 2.1°. In the conventional group, the mean MA was varus 10.6° preoperatively and valgus 0.1° postoperatively via the radiograph. The mean preoperative posterior slope angle (PSA) was 11.0°, which decreased to 9.0° in the navigation group. The mean preoperative PSA was 10.4°, which decreased to 6.4° in the conventional group(p = 0.000). There was a positive correlation between measured data taken under navigation and by radiographs(r > 0.3, P < 0.05). The mean correction angle was significantly more accurate in the navigation group(p < 0.002). The variability of the correction was significantly lower in the navigation group (2.3° versus 3.7°, p = 0.012), and the distribution of MA was also narrower in the navigated group.

We concluded that navigation provides reliable real-time intraoperative information and may increase accuracy, and improve the precision of closed-wedge HTO.

We reviewed the outcome of distal chevron metatarsal osteotomy without tendon transfer in 19 consecutive patients (19 feet) with a hallux varus deformity following surgery for hallux valgus. All patients underwent distal chevron metatarsal osteotomy with medial displacement and a medial closing wedge osteotomy along with a medial capsular release.

The mean hallux valgus angle improved from −11.6° pre-operatively to 4.7° postoperatively, the mean first-second intermetatarsal angle improved from −0.3° to 3.3° and the distal metatarsal articular angle from 9.5° to 2.3° and the first metatarsophalangeal joints became congruent post-operatively in all 19 feet. The mean relative length ratio of the metatarsus decreased from 1.01 to 0.99 and the mean American Orthopaedic Foot and Ankle Society score improved from 77 to 95 points.

In two patients the hallux varus recurred. One was symptom-free but the other remained symptomatic after a repeat distal chevron osteotomy. There were no other complications.

We consider that distal chevron metatarsal osteotomy with a medial wedge osteotomy and medial capsular release is a useful procedure for the correction of hallux varus after surgery for hallux valgus.

Purpose: To document outcomes and patient satisfaction in relation to the incision used following clavicle fracture fixation. In literature, the incidence of incisional numbness following operative fixation of clavicle fractures is reported to be between 7–29%. Such wound related problems contribute significantly to the dissatisfaction of patients with operatively treated clavicle fractures. Wound related problems can be bothersome and disabling and this is poorly documented.

Method: All primary clavicle fractures treated with plating at the Alfred Hospital between 01/06/2003 and 01/06/2006 were included in the study. Patients were asked to complete paper-based questionnaires assessing satisfaction, pain, scar satisfaction, presence of numbness and the degree of disability following clavicle fixation. Their clinical notes and X-rays were reviewed for evaluation. The study sample was then divided into two groups; horizontal incision versus vertical incision then the data was analysed.

Results: The response rate was 65% (35/54). 74% of patients reported as having “good” or better outcome following their clavicle fracture fixation. There was no statistically significant difference in pain scores. However, there were statistically significant differences observed in the presence of numbness (vertical 21% versus horizontal 62%) and the disability from the numbness between the two incision types. Overall satisfaction between the two groups was also significantly different.

Conclusion: This study confirms that scar-related problems significantly affect the satisfaction following plating of clavicle fractures and numbness appears to be one of the most significant factors. Vertical incisions appear to reduce the incidence of numbness and lead to better patient satisfaction. Our results suggest that vertical incision is an attractive alternative approach in clavicle fracture fixation.

We investigated the fracture-free survival of long bones stabilised by a telescopic intramedullary rod (TIMR) in patients with osteogenesis imperfecta with respect to the remodelling status of fracture or osteotomy sites and TIMR regions, in order to identify risk factors for fracture. A total of 44 femora and 28 tibiae in 25 patients with a mean age of 5.0 years (1.9 to 10.5) at presentation were studied. There were six patients with Sillence type I, five with type III, 13 with type IV and one with type V osteogenesis imperfecta. All received bisphosphonate treatment at the same stage during the mean follow-up of 7.3 years (0.5 to 18.1). The fracture-free survival was estimated at 6.2 years (95% confidence interval 5.1 to 7.3) by Kaplan-Meier analysis. More than half the fracture or osteotomy sites remained in a less-remodelled state at the latest follow-up or time of fracture. Of the 33 fractures, 29 (87.9%) occurred in long bones containing a less-remodelled site, and these fractures were located at this site. The relative fracture risk at the rod tip was significantly greater than in any other TIMR region (p < 0.001), and this was higher in bone segments having a less-remodelled site.

This study shows a persistent fracture risk in TIMR-stabilised long bones, especially at less-remodelled fracture or osteotomy sites and at the rod tip.

Background: The purpose of this study was to evaluate the results after hallux valgus surgery by transar-ticular adductor tenotomy, distal Chevron metatarsal osteotomy and Akin phalangeal osteotomy using medial one incision.

Materials and Methods: From June 2004 to June 2007, eighty feet of 54 patients were included in this study. During the same period, other cases of hallux valgus correction were excluded. Thirty seven patients underwent both feet operation at the same time and 17 patients underwent single foot operation. Among the 37 patients who underwent both feet operation, proximal metatarsal osteotomy was performed for contralateral 11 feet at same time, and these cases with proximal metatarsal osteotomy were excluded from this study. Postoperatively, all patients were allowed immediate full weight bearing walking. Patients were evaluated according to the American Orthopedic Foot and Ankle Society(AOFAS) hallux metatarsophalangeal-interpha-langeal scale, VAS(visual analogue scale), post-operative complications and radiologic parameters such as hallux valgus angle, intermetatarsal angle, T-test was used to evaluate the degree of hallux valgus and intermetatarsal angles. The mean follow up period was 25.9 months.

Results: At the last follow up, the mean AOFAS hallux metatarsophalangeal-interphalangeal scale increased from 48.7 to 91.9. The Mean VAS score decreased from 7.1 to 0.8 post-operatively. The mean hallux valgus angle of 31.4° (range, 22° to 46°) improved to 5.3 ° (range, 0° to 20°) after the operation. The mean intermetatarsal angle also showed improvement from 12.3° (range, 7° to 16°) to 5.5 ° (range, 2° to 11°). Comparison between preoperative and postoperative hallux valgus and intermetatarsal angles was done by T test in dependent groups, which showed statistical significance (p< 0.05). There were three cases of mild hallux varus and three cases of recurred valgus deormity. No avascular necrosis or union problem was observed on the radiographs in any of the patients.

Conclusion: Hallux valgus deformity correction by transarticular adductor tenotomy, distal Chevron metatarsal osteotomy and Akin phalangeal osteotomy using medial one incision has the advantages of lower morbidity and less scar without avascular necrosis of the metatarsal head.

Background: Although many of the contemporary fixed- and mobile bearing total knee systems have been using extensively world wide, there is limited information available regarding the incidence of osteolysis of the well functioning total knee arthroplasties. We performed this study to evaluate the clinical and radiographic outcomes, the incidence of osteolysis, the revision rates and implant survivorship of the fixed- and mobile-bearing total knee arthroplasties at ten to seventeen years follow-up.

Methods: We compared 488 patients (894 knees) who received a fixed-bearing total knee replacement and 445 patients (816 knees) who received a mobile-bearing total knee replacement. There were 187 men and 301 women (mean age, 58.6 years) in the fixed-bearing group and 167 men and 278 women (mean age, 55.7 years) in the mobile-bearing group. The mean follow-up was 12.6 years (range, ten to seventeen years) in the fixed-bearing group and 14.1 years (range, twelve to seventeen years) in the mobile-bearing group.

Results: The mean postoperative Knee Society knee and functional scores were 92.9 points and 83.5 points, respectively in the fixed-bearing group. The mean postoperative Knee Society knee and functional scores were 90.7 points and 83.8 points, respectively. Incidence of osteolysis was 1.6% (fourteen of 894 knees) in the fixed-bearing group and it was 2.2% (eighteen of 816 knees) in the mobile-bearing group at the final review. Revision rate was 3.7% (thirty-three of 894 knees) in the fixed-bearing group and it was 2.7% (twenty-two of 816 knees) in the mobile-bearing group. Kaplan-Meier survivorship of the fixed-bearing group was 96.3% (95% confidence interval, 0.87–1.0) at 13 years follow-up and it was 97% (95% confidence interval, 0.90–1.0) of the mobile-bearing group at 14 years follow-up.

Conclusions: The present study demonstrates that the clinical and radiographic outcomes, the incidence of osteolysis, the rate of revision and the implant survivorship were similar between the fixed-bearing and mobile-bearing total knee arthroplasties.

Background: Alumina ceramic-on-highly cross-linked polyethylene (Al-on-X-linked PE) is attractive because of the potential for reduced wear, osteolysis and loosening of the component. The purpose of this study was to evaluate the clinical and radiographic outcomes of cement-less total hip arthroplasties (THAs) using Al-on-X-linked PE bearing and to determine the rates of osteolysis using radiographs and computer tomographic (CT) scans in young patients with osteonecrosis of femoral head.

Methods: Consecutive primary cementless THAs using Al-on-X-linked PE bearing were performed in 71 patients (73 hips) who were younger than 50 years of age with osteonecrosis of the femoral head. There were 48 men (51 hips) and 23 women (23 hips). The average age at the time of the index arthroplasty was 45.5 years (range, 20 to 50 years). Osteolysis was evaluated using radiographs and CT scanning. The average follow-up was 10.5 years (range, 10 to 13 years).

Results: The mean preoperative Harris hip score was 50.6 points (range, 27 to 55 points), which was improved to 96 points (range, 85 to 100 points) at the final follow-up. Preoperative functional activity was improved significantly (p=0.001) at the latest follow-up. All acetabular and femoral components were fixed by bone ingrown. The mean polyethylene linear penetration was 0.05±0.02 mm per year (range, 0.02 mm to 0.08 mm per year). Radiographic and CT scans demonstrated that no acetabular or femoral osteolysis was detected in any hip at the latest follow-up.

Conclusions: The current generation of anatomic tapered cementless femoral component with Al-on-X-linked PE bearing is functioning well with no osteolysis at a 10-year minimum and average of 10.5-year follow-up in this series of young patients with osteonecrosis of the femoral head.

We evaluated the efficacy of anterior fusion alone compared with combined anterior and posterior fusion for the treatment of degenerative cervical kyphosis. Anterior fusion alone was undertaken in 15 patients (group A) and combined anterior and posterior fusion was carried out in a further 15 (group B). The degree and maintenance of the angle of correction, the incidence of graft subsidence, degeneration at adjacent levels and the rate of fusion were assessed radiologically and clinically and the rate of complications recorded. The mean angle of correction in group B was significantly higher than in group A (p = 0.0009). The mean visual analogue scale and the neck disability index in group B was better than in group A (p = 0.043, 0.0006). The mean operation time and the blood loss in B were greater than in group A (p < 0.0001, 0.037). Pseudarthrosis, subsidence of the cage, and problems related to the hardware were more prevalent in group A than in group B (p = 0.034, 0.025, 0.013).

Although the combined procedure resulted in a longer operating time and greater blood loss than with anterior fusion alone, our results suggest that for the treatment of degenerative cervical kyphosis the combined approach leads to better maintenance of sagittal alignment, a higher rate of fusion, a lower incidence of complications and a better clinical outcome.

Background: Whether total knee arthroplasty using computer-assisted surgical navigation can improve the limb and component alignment is a matter of debate. We hypothesized that total knee arthroplasty using computer-assisted surgical navigation is superior to the conventional total knee arthroplasty with regard to the precision of implant positioning.

Methods: Sequential simultaneous bilateral total knee arthroplasties were carried out in 160 patients (320 knees). One knee was replaced using a computer-assisted surgical navigation system and the other conventionally without using computer-assisted surgical navigation. The two methods were compared for accuracy of orientation and alignment of the components determined by radiographs and computed tomographs. The mean follow-up was 3.4 years.

Results: The mean preoperative Knee Society score was 26 points in the computer-assisted total knee arthroplasty group, which was improved to 92 points postoperatively and it was 25 points, which improved to 93 points post-opertively in the conventional total knee arthroplasty group. Ranges of motion of the knees were similar in both groups. The operating and tourniquet times were significantly longer in the computer-assisted total knee arthroplasty group than in the conventional total knee arthroplasty group (P< 0.001). Accuracy and the number of outliers of component position between the two groups were not significantly different (P> 0.05).

Conclusions: Our data demonstrated that total knee arthroplasty using computer-assisted surgical navigation did not result in more accurate implant positioning than that achieved in conventional total knee arthroplasty, determined by both radiographs and computed tomographs.

Background: The main goals of total knee arthroplasty are pain relief and improvement of function and range of motion. To ascertain whether posterior cruciate-retaining-flex total knee prosthesis would improve pain, function and range of motion, we asked whether knee and pain scores, ranges of motion, WOMAC score, patient satisfaction, and radiographic results would be better in the knees with a high-flexion posterior cruciate-retaining prosthesis than in the knees with a standard posterior cruciate-retaining prosthesis.

Methods: Fifty-four patients (mean age, 69.7 years) received a standard posterior cruciate-retaining knee prosthesis in one knee and a high-flexion posterior cruciate-retaining knee prosthesis in the contralateral knee. Five patients were men, and forty-nine were women. The minimum follow-up was three years (mean 3.1 years). At each follow-up, the WOMAC score and range of knee motion were evaluated and patients were assessed clinically and radiographically with use of the knee-rating systems of the Knee Society and The Hospital for Special Surgery.

Results: The mean postoperative Knee Society and Hospital for Special Surgery knee scores were 93.7 and 89 points, respectively in the knees with a standard posterior cruciate-retaining prosthesis and those were 93.9 and 90 points, respectively in the knees with a high-flexion posterior cruciate-retaining prosthesis. The mean postoperative WOMAC score was 22 points. Postoperatively, the mean non-weight and weight bearing ranges of motion were 131° (range, 90° to 150°) and 115° (range, 75 to 145°), respectively in the knees with a standard prosthesis and those were 133° (range, 90° to 150°) and 118° (range, 75 to 145°), respectively in the knees with a highflexion prosthesis. Patients satisfaction and radiographic results were similar in both groups. No knee had aseptic loosening, revision, or osteolysis.

Conclusions: After a minimum follow-up of three years, we found no significant differences between the two groups with regard to range of knee motion or clinical and radiographic results.

We undertook a study in which 138 female patients with a mean age of 71.2 years (51 to 82) received a standard NexGen CR-flex prosthesis in one knee and a gender-specific NexGen CR-flex prosthesis in the other. The mean follow-up period was 3.25 years (3.1 to 3.5). The aspect ratios of the standard and gender-specific prostheses were compared with that of the distal femur.

The mean post-operative Knee Society knee scores were 94 (70 to 100) and 93 (70 to 100) points and the function scores were 83 (60 to 100) and 84 (60 to 100) points for the standard implants and the gender-specific designs, respectively. The mean post-operative Western Ontario and McMaster Universities score was 26.4 points (0 to 76). Patient satisfaction, the radiological results and the complication rates were similar in the two groups. In those with a standard prosthesis, the femoral component was closely matched in 80 knees (58.0%), overhung in 14 (10.1%) and undercovered the bone in 44 (31.9%). In those with a gender-specific prosthesis, it was closely matched in 15 knees (10.9%) and undercovered the bone in 123 (89.1%).

Since we found no significant differences between the two groups with regard to the clinical and radiological results, patient satisfaction or complication rate, the goal of the design of the gender-specific CR-flex prosthesis to improve the outcome was not achieved in our patients.

The purpose of this study is to identify clinical and radiographic results of 78 uncemented total hip arthroplasties using Metasul^® metal on metal bearings with Wagner standard cup and proximal hydroxyapatite coated CLS stem.

Mean age was 39 years and average follow-up period was 11.7 years. Mean Harris hip score had improved from 51.4 points preoperatively to 95.2 points finally. There were 2 hips with progressive osteolysis around the acetabular cup. Of them, one hip was revised due to loosening of the cup, and the other was observed because of patient’s refusal to revise. In histopathologic findings on osteolytic area, a lot of macrophage phagocytizing metal debris and perivascular lymphocyte infiltration were found. Immunohistochemical analysis suggested delayed metal hypersensitivity. Serum cobalt levels in hips with osteolysis were not higher than those in hips without osteolysis.

Early osteolysis with sudden onset of groin pain in few hips remains a concern.

We suggested a new concept of buffered implant fixation. It is a cementless fixation using a buffer instead of the cement between the bone and the implant. We investigated the feasibility of the buffered implant fixation using a rat model. In our previous study, we measured the amount of bone around the implant to compare the buffered implant fixation with the cemented fixation. The results showed the difference in change of Bone Volume/Total Volume (BV/TV) with time between the buffered fixation and the cemented fixation. Now, in this study, we are comparing the mechanical interface strength between two fixations.

After micro CT scanning, the specimens were used for mechanical push-out test to measure the interface shear strength at the buffer-bone or cement-bone interface. The distal side of the femur was carefully removed to expose the whole distal region of the implant while the proximal side of femur was cut carefully with diamond saw (Metsaw, R& B Inc., Korea) until the proximal end of cement or buffer is exposed. The femur was embedded into a push-out jig with a plaster. The push-out jig was mounted in a material testing machine (KSU-10M, Kyungsung testing machine, Korea) and loaded at a rate of 0.01mm/s. The apparent interface strength was calculated by dividing the peak force by the surface area of the buffer or cement.

After 2 weeks, the apparent interface strength is 217.0 ± 280.0(average ± standard deviation) for buffer and 472.4 ± 381.1 for cement; after 4 weeks, 92.9 ± 67.6 and 268.1 ± 197.9; after 12 weeks, 441.9 ± 467.1 and 201.8 ± 132.3, respectively. The buffered fixation showed gain in strength with time while the cemented fixation showed reverse tendency but the interaction by ANOVA was not significant (p=0.125). Even though the excellence of buffer fixation was not clearly confirmed because of small sample size and high variance, the feasibility of the buffer fixation was shown.

However, further studies are necessary to improve the buffered implant fixation. To enhance the cell adhesion and biocompatibility, it is necessary to modify the surface of polyetheretherketone (PEEK) such as by plasma treatment or biological coating. Also, an animal test using a higher level animal such as dog or pig is necessary.

The purpose of this study is to evaluate the clinical and radiographic results of 20 patients(27 hips) who underwent primary bipolar hemiarthroplasty with non-cemented femoral stem and biarticular cup from January 1989 to April 1999 who were followed for more than nine years. Average follow up was 13.4 years(range: 9~19 years). The type of non-cemented femoral stem was Harris-Galante type in ten hips, Multilock porous coated stem in seven hips, and Multilock porous and tricalcium phosphate coated stem in ten hips. The etiology of osteonecrosis of the femoral head was idiopathic in eleven hips, alcohol abuse in twelve hips and steroid administration in four hips. According to Ficat’s grading system, all twenty-seven hips were in stage. Clinically, we evaluated the Harris Hip scores. We also evaluated the radiographic measurements around the femoral stems and the bipolar cups.

The average Harris Hip score improved from 57.2 points to 89 points; and 2(7.4%)hips were associated with thigh pain and 5(18.5%) hips with groin pain. Around the femoral stem there was progressive radiolucent line more than 1mm in width in 1(3.7%) hip, and osteolysis was present in 9(33.3%) hips. On evaluation of radiographs for stability of fixation, we found that 21 hips(77.8%) showed osseous ingrowth, 5 hips(18.5%) showed stable fibrous ingrowth and one hip(3.7%) showed unstable fixation. The osteolysis around the acetabulum was found in 9 hips(33.3%). Two hips showed evidence of migration of the bipolar cup. Five hips(18.5%) showed acetabular cartilage erosion more than 1mm. Seven hips(25.9%) required conversion to total hip arthroplasties, and in two hips, femoral stems were revised. The causes of failure of bipolar cup was central migration in 2 hips, and dissociation of femoral head, extensive osteolysis, and unknown groin pain after trauma in one each. Two bipolar cups were converted to acetabular cup at revision of the femoral stem. The overall failure rate of the primary operation was 26%. The survivorship of non-cemented femoral stem was 92.6% and 74% in bipolar cup at minimum 9 years follow up.

The current study demonstrated favorable results after bipolar hemiarthroplasties with non-cemented femoral stems. However, the osteolysis around the femoral stems and the acetabular cup emerged as main causes of need for surgical revision.

The use of polymethylmethacrylate (PMMA) in orthopaedic reconstructive surgery can increase the possibility of cardiovascular dysfunction remains a debate. This study was undertaken to determine if cemented hemiarthroplasty is safe in treatment of femoral neck fracture in patients with ischemic heart disease. Between March 1999 and February 2004, we performed cemented hemiarthroplasties for displaced femoral neck fractures on 158 consecutive patients. This retrospective study consisted of 44 patients with ischemic heart disease(group 1) and 58 patients of age matched control(group 2). We compared the mortality rate, the incidence of deep vein thrombosis (DVT), pulmonary embolism, cerebrovascular disease, dislocation, deep infection, the amount of postoperative blood loss, and the grade of cementation by Barrack in radiograph between two groups.

No difference was found in perioperative mortality rate, deep infection rate, the incidence of DVT or pulmonary embolism, the newly developed heart ischemic event or brain hemorrhagic lesion between the two groups. But there were more incidence of dislocation related to weakness by past brain ischemic lesion and the newly developed brain ischemia in patients of group 1 than group 2(p < 0.05). More importantly, six patients in group 1 had transient symptoms of dyspnea, signs of hypotension, and bradycardia during two days postoperatively, which is suspicious of embolic phenomenon, even though it was not confirmed.

More closer and careful observations for the occurrence of dislocation related to previous brain ischemia, or newly developed brain ischemic lesion or embolic phenomenon and appropriate thromboprophylaxis are necessary in patients with ischemic heart disease after a cemented hemiarthroplasty for the treatment of femoral neck fracture.

We have analyzed the long-term clinical and radiological results of 169 total knee replacements(TKRs) for rheumatoid arthritis over 10 years. The average follow up period was 12.8(10–17.6) years.

The flexion contracture was improved from average 25.0 to 2.9 degrees. But the angle of great flexion had decreased from average 128.0 to 114.7 degrees. At the final follow up, the American Knee Society knee score was 87.5 and function score 76.5 in average. The revision arthroplasty was performed in 20 cases, but only 4 cases were done before 10 years after the primary TKRs. The survival rate of the implant was 97.9% at 10 years and 85.3% at 14 years in Kaplan-Meier survivorship analysis. But just after 10 years, problems such as osteolysis and periprosthetic fractures started to occur increasingly. 10-year follow up results is just the 10-year results only, not the long-term or final results of TKRs for rheumatoid arthritis.

The purpose of this study was to evaluate the effect of decreasing tibial slope on extention gap during posterior stabilized total knee arthroplasty. 110 posterior stabilized total knee arthroplasties were studied for 2 groups;

having flexion contractures(n=35),

In each group, we measured the decrease of tibial slope and frequency of additional distal femoral resecions that were done due to insufficient extension gap in comparison with flexion gap during posterior stabilized total knee arthroplasty. We also compared frequencies of additional distal femoral resections between 2 parts having more and less slope decrease in each groups.

In each group, tibial slope decrease were 8.7 degrees, 7.4 degrees(p=0.145) and frequencies of additional resection were 51.4%, 24%(p=0.005) in average. In 2 parts having more and less slope decrease in each group, frequencies of additional resection were 44.4% vs 58.8%(p=0.505), 13.2% vs 35.1%(p=0.032). Results suggested that more decrease of tibial slope reduced frequency of additional distal femoral resection during posterior stabilized total knee arthroplasty in group having no flexion contracture.

Decreasing tibial slope can be considered as a factor influencing on extension gap during posterior stabilized total knee arthroplasty. The estimation of predictable tibia slope decrease through preoperative radiologic findings can be beneficial in performing succeful posterior stabilized total knee arthroplasty.

Ultra-high molecular weight polyethylene (UHMWPE) has been used for the bearing liner or inlay components in total joint replacements such as total hip, knee, and artificial disk since 1960’s. UHMWPE components generate wear debris during articulation, which play a key role in osteolysis, subsequent aseptic loosening, and eventually revision surgery. Efforts to solve the wear problem in UHMWPE and to quantify the amount of wear have driven many studies. But in vivo radiographic penetration depth measurement is the result of both wear and viscoelastic creep. Previous study reported that over 70% of the dimensional changes in UHMWPE acetabular cups were due to creep. Creep deformation was quantified under the static and dynamic compressive pressures (2, 4, 8Mpa) that are clinically relevant for the hip joint loads in normal motions. However, according to the finite element stress analyses in UHMWPE components under the active motions in hip, knee, and artificial disk replacements, very high level of contact pressures locally ranged from under 10MPa up to over 60Mpa. In this study, we quantified the creep of UHMWPE under the several high levels of dynamic compressive pressures and compared the results from the previous results.

For creep tests, UHMWPE rectangular blocks (10mm long, 10mm wide, 8mm thick) were manufactured from molded unirradiated Chirulen^® 1020 sheet (MediTECH, Deutchland). MTS 858 hydraulic test machine was used for conducting the dynamic compressive creep tests under the four different sinusoidal (1Hz) maximum pressures of 10, 20, 40, and 60MPa and minimum pressures of 1, 2, 4, and 6MPa, respectively. All tests were conducted for a total duration of 4×103 minutes at ambient conditions. During the test the displacements of crosshead were stored and the changes in thickness of block specimen devided by the initial thickness were calculated to get the creep strain.

The mean dynamic compressive creep strain increased as the loading time increased and had a linear relationship (R2=0.96) with the logarithmic scale of time for all maximun pressures. Over 90% of total creep strain occurred within the first 103 minutes. The rates of creep strain (slopes of curve fitting in logarithmic scale of time) for each maximum pressure were listed in Table 1 with the rates of creep strain for low maximum pressures from the previous study [3]. The rates of creep strain increased linearly as the maximum pressure increased for both current study (R2=0.96) and previous study (R2=0.99). The slope of linearity for the current study with high levels of contact pressures was a little larger than that for the previous study with low levels of contact pressures. This difference in the slope of linearity between current and previous studies lies in the creep recovery during measurement of specimen thickness by micrometer in the previous study. Neglecting this difference, the results of current study can be extrapolated to anticipate the creep strain of UHMWPE under the dynamic compression for the low levels of contact pressures.

The purpose of this study was to review the total ankle arthroplasties performed in consecutive series of 78 ankles and to determine the short-term results in cases with over 12 months follow-up. Preoperative diagnoses were post-traumatic osteoarthritis in 40 ankles (51.3%), primary osteoarthritis in 32 ankles (41.0%), and systemic arthritis in six ankles (7.7%). HINTEGRA^® (Newdeal SA, Lyon, France) total ankle system was used in all cases

Fifty-five total ankle arthroplasties including four revision cases, followed up for over 12 months (range, 13~49 months) were included in this study. Ankles were divided into three groups according to the coronal plane deformity in preoperative standing ankle AP radiograph; Varus (≥10°; 20 ankles (39.2%)), neutral (< 10° varus or valgus; 25 ankles (49%)), and valgus (≥10° valgus; 6 ankles (11.8%)). Various additional surgeries were performed simultaneously with the arthroplasty to correct the deformities; deltoid ligament release (25 cases), posterior tibialis tendon lengthening (2 cases), peroneus longus tendon transfer to brevis (5 cases), lateral ankle reconstruction with modified Broström procedure (4 cases), lateral closed-wedge calcaneal osteotomy (3 cases), percutaneous heel cord lengthening (19 cases), and gastrocnemius recession (1 case). In one patient with severe valgus deformity, staged total ankle arthroplasty was conducted after primary triple arthrodesis.

Preoperative and postoperative visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, range of motion (ROM), as well as patient’s satisfaction and willingness to receive the operation again were evaluated The results were compared among the three groups. Serial radiographs were reviewed for any radiological changes.

AOFAS score has improved from 54.3 ± 11.4 pre-operatively to 79.2 ± 11.4 at last follow-up. VAS has decreased from 6.8 ± 1.6 to 3.2 ± 1.6. Mean improvement in ROM was 15.6 ± 16.2 degrees. Forty-eight cases (873%) were satisfied with excellent or good results and 49 cases (89.1 %) were willing to receive the operation again. No significant differences in the postoperative VAS (p=0.14), AOFAS score (p=0.79), and ROM (p=0.06) were found among the three groups. Hetero-topic ossifications were observed in 12 cases (23.5%) and periosteal reactions proximal to medial malleolus occurred in four cases (7.8%).

Perioperative complications include one intraoperative medial malleolus fracture which was successfully managed with two cannulated-screws, and one medial malleolar stress fracture at six weeks after surgery which has healed spontaneously. One case with osteolysis around tibial screws was managed with bone graft. One case with deep fungal infection was converted to arthrodesis after infection control. Four ankles had to be revised including three cases of polyethylene bearing change due to dislocation, and one case of tibial component and bearing change due to loosening. The patient with revised tibial component was converted to arthrodesis due to recurred loosening. The Kaplan-Meier cumulative survival rate was 90.9% at 12 months and 87.8% at 49 months postoperatively.

The short term clinical results of HINTEGRA ankles showed favorable results. No significant differences were observed among different groups of coronal plane deformities when adequate additional surgeries were performed simultaneously. Long term follow-up study is required.

Personalized three-dimensional (3D) femoral geometry is a great aid in the surgical planning. X-ray image is still essential to diagnose and plan surgery in total hip replacement due to its lower cost and lower dose of radiation than computer tomography (CT). The purpose of the current study is to improve 3D reconstruction process using conventional X-ray images incorporating the anatomical parameters for building up the femoral model.

For 3D reconstruction, the personalized femoral appearance and parameters were firstly prepared from X-ray images and the referential CT model with anatomical parameters was modified as follows: the axial scaling, shearing transformation and radial scaling. In this study, the reconstruction algorithm was applied to X-ray images obtained from the 28 years old male.

The current study showed that this 3D reconstruction technique is clinically useful and feasible because this method was based on anatomical parameters and used for whole femur. This result can provide the basic model of individual femur for using finite element method of hip or knee joint, and designing the customized hip and knee implant. In addition, this result can be applied to the visualized 3D model with more effective parameters of individual femur in the surgery navigation system.

The cemented and cementless implant fixations are popular in orthopaedic arthroplasty. However, these implant fixations have some problems such as cement failure, wear debris, stress shielding, revision and so on. To overcome these problems, we are developing a new concept of buffered implant fixation which uses a bone-friendly buffer between the implant and the bone. In this study, we performed a finite element analysis to evaluate the buffered implant fixation in comparison with cemented and cementless implant fixations in mechanical aspects. In addition, we investigated the effect of buffer taper angle to the stress distribution in the buffered implant fixation.

Three-dimensional FEA of the cemented, cementless and buffered fixation were performed using the ABAQUS program. In these FEA, the ‘standardized femur’, which is the composite femur model supplied by Pacific Research Lab., was used as the bone model and the CPT stem and the Versys Fibermetal Midcoat stem were modeled for the cemented fixation and the cementless fixation, respectively. These three-dimensional models were meshed using the tetrahedral elements with 4 nodes (C3D4) and the additional contact definitions. The buffered implant fixation is similar with the polished cemented fixation except the material between the implant and the bone. The polyetheretherketone (PEEK) was selected as the buffer material. Also, several taper angles of buffer were simulated to change the stress distributions in the buffered fixation. The external load three times of mean body weight (74.3 kg) was cyclically loaded at the femoral head with the angle of 20° in adduction and 6° in flexion while the distal end of femur was fixed.

In the buffered implant fixation, the taper-locked effects were observed. The buffered fixation had greater cyclic compression for the bone compared to the cemented fixation. Also, the failure probability of the buffer in the buffered fixation was less than that of the cement in the cemented fixation. The risk factors in the buffer were 0.148 for the tension and 0.176 for the compression while, the risk factors of cement in the polished cemented implant fixation were over than 1. Moreover, the buffered fixation had widely distributed compression compared to the cementless fixation and the stress distribution could be modified easily to change the taper angle of buffer. The FEA results showed that the buffered implant fixation would provide an appropriate mechanical environment.

The purpose of this study was to compare the clinical and radiological results of the PFC flex mobile bearing design with those of the LPS flex fixed bearing design in high-flex total knee arthroplasty.

Between January 2005 and November 2006, forty-six patients who received PFC flex mobile bearing prosthesis in one knee and LPS flex fixed bearing prosthesis in the contralateral knee followed up for a minimum 2 years were evaluated. Clinical results were assessed using the ROM, HSS score, the Knee rating systems of the knee society, WOMAC score and SF-36. Radiological results were evaluated tibio-femoral angle and loosening or osteolysis of components. We subdivided preoperative less 90 degree and more 90 degree in each group.

Mean ROM range of last follow up was increased to 131.1 degree in LPS group and 130.1 degree in PFC group. But there was no significant difference between the two groups. HSS score, knee pain and function score, WOMAC score, SF-36 score didn’t differ significantly between two groups. But descending stairs, rising from sitting, bending to the floor more improved significantly in LPS group. T-F angle was changed from preoperative 8.2 degree varus to a postoperative 4.8 degree valgus. No knee had aseptic loosening or osteolysis.

Postoperative ROM was increase significantly in both groups. We found no significant differences between the two groups with regard to clinical and radiological parameters excepts descending stairs, rising from sitting, bending to the floor in WOMAC score. There was no aseptic loosening or osteolysis but needed long term observation about these concerns.

Purpose: We have performed this study to compare the postoperative maximal flexion angle(MFA) of high-flex implants with that of conventional implants in PCL-substituted total knee arthroplasty(TKA).

Materials and Methods: The staged sequential bilateral TKAs were performed in Group 1, 35 patients(70 knees) with osteoarthritis of both knee. The conventional implant and the high-flex implant were both used in each patient by randomized method. The postoperative MFA of both type of implants was measured and analyzed at 1 year after surgery. To evaluate unidentified factors that might influence the results, such as the differences derived from personal characteristics during postoperative rehabilitation process achieving the range of motion of knee, we also analyzed the other patient groups, which were composed of Group 2(10 patients, 20 knees) bilaterally operated with conventional implants, Group 3(7 patients, 14 knees) bilaterally with high-flex implants, Group 4(13 patients, 13 knees) unilaterally with conventional implants and Group 5(17 patients, 17 knees) unilaterally with high-flex implant.

Results: In Group 1, the average postoperative MFA of high-flex implant and that of conventional implant showed no significant difference.(131.7 and 131.9 degree each) The average postoperative MFA in Group 1,2,3,4 and 5 showed no significant difference either.

Conclusion: This study indicates that the high-flex implant alone does not seem to improve the MFA as compared to the conventional implant. The status of the contralateral knee and the personal characteristics during rehabilitation seem to be more important factors in increasing the maximal flexion.