The reliability of modern alumina bearings in total hip arthroplasty—Update to a 2006 report

Ceramic components׳ clinical fractures in total hip arthroplasty (THA) are a rare but, nonetheless, serious complication. As a result of continued improvements in ceramic material quality, manufacturing methods, and implant design made over the last 30 years, the incidence of such failures has been drastically reduced. In this report, the frequency of these ceramic components׳ clinical failures in THA will be examined. In addition, some information regarding the contribution that can be made by the surgeon to enhance the reliability of ceramic components will also be presented. In order to get a broad view, the largest supplier of these components, CeramTec Medical Products (Plochingen, Germany), was contacted, and they agreed to share their most recent data. In the year 2000, the largest supplier of alumina–ceramic bearings for orthopedic applications (CeramTec GmbH, Plochingen, Germany) began a rigorous program of collecting clinical fracture data for all of its ceramic components. The clinical fracture data for the period of January 2000–June 2013 are reported here, with a review of the material properties, historical component fracture trends, and relative risk of fracture associated with alumina THA bearings. The data reported is divided into two separate groups. The first one is the incidence of clinical fracture of the Biolox^® forte material. This is their original material developed in the 1970s and is still available today and optimized over the years. The overall clinical fracture rate of these alumina components was 0.021%, or 21 in 100,000, during the January 2000–June 2013 time period. The second group is composed of components manufactured from their Alumina Matrix Composite, Biolox^® delta. The overall clinical fracture rate for these components is 0.0001% or 1 in 100,000. Almost 80% of these alumina bearing failures occurred within 36 months following surgery. Using the latest material and increasing femoral head diameter were associated with a substantially reduced risk of fracture. Alumina bearings used in modern THA implants are safe and reliable, with a very low risk of failure. Improvements in the materials, developments in the manufacturing, the introduction of the Alumina Matrix Composite, and the trend to utilize larger-diameter ball heads are likely to continue to reduce the concerns that have been in the mind of surgeons using ceramics in THA.     

The posterior approach to pelvic ring injuries: A technique for minimizing soft tissue complications

Surgical techniques and fixation strategies for the treatment of unstable posterior pelvic ring injuries continue to evolve. The safety of the posterior surgical approach in particular has been questioned due to historically high rates of wound related complications. More contemporary studies have shown lower infection rates, however concern still persists. These concerns for infection and wound necrosis have led, in part, to increased interest in closed reduction and percutaneous fixation for treatment of these injuries but an open posterior approach remains the optimal strategy in some injury patterns. We describe herein a modified posterior approach to the pelvis designed to minimize wound related complications and present our clinical results demonstrating wound complication rates consistent with contemporary publications.     

Congenital dysplasia involving both medial and inferior recti: clinical features and surgical outcomes

AIM: To investigate the clinical features and surgical outcomes of congenital dysplasia involving both inferior recti (IR) and medial recti (MR) muscles. METHODS: A retrospective review was conducted including cases of simultaneous congenital dysplasia of IR and MR that were diagnosed and surgically treated at the Zhongshan Ophthalmic Center, Sun Yat-sen University, China, from July 2009 to November 2019. Ocular motility, ocular alignment at distance (6 m) and near (33 cm) by prism alternating cover test and stereoacuity were assessed in all patients before and after surgery. RESULTS: A total of five patients (four males and one female; three with right eye and two with left eye congenital dysplasia) were included in this review. The patients ranged in age from 10 to 42y (21±13.4y). The main clinical findings were hypertropia and exotropia of the affected eye, along with motility limitations in adduction and depression. Lateral rectus (LR) recession/transposition combined with IR resection was performed in one case. Two scheduled surgeries were performed in four cases, with one involving superior rectus recession and IR resection and the others LR recession and MR resection. Mean±SD pre-surgical exotropia of 51.0±31.11 prism diopter (PD) and hypertropia of 29.20±7.12 PD in the primary position were decreased to 3.6±12.90 and 3.2±10.09 PD, respectively, at two years after surgery, with a success rate of 60% and an under-correction rate of 40%. CONCLUSION: The main clinical features associated with simultaneous MR/IR congenital dysplasia are hypertropia and exotropia of the affected eye along with motility limitations in adduction and depression. Scheduled two-stage surgeries achieved a success rate of 60%.     

Cost-Effective Analysis of Dual-Energy Computed Tomography for the Diagnosis of Occult Hip Fractures Among Older Adults

ObjectiveEarly and accurate diagnosis of hip fractures minimizes morbidity and mortality. Although current guidelines favor magnetic resonance imaging (MRI) for the diagnosis of occult hip fractures, a new technology called dual-energy computed tomography (DECT) seems an effective alternative. This article investigates a potentially cost-effective strategy for the diagnosis of occult hip fractures in older adults in Singapore.MethodsA decision tree model was developed to compare costs from a payer’s perspective and outcomes in terms of quality-adjusted life-years (QALYs) of different imaging strategies for diagnosing occult hip fracture, comparing MRI with DECT supplementing single-energy computed tomography (SECT) and SECT alone. Model inputs were obtained from local sources where available. Sensitivity analyses are performed to test the robustness of the results.ResultsThe MRI strategy was dominated by the DECT strategy, whereas DECT supplementing SECT provided 0.30 more QALYs at an incremental cost of SGD106.41 with an incremental cost-effectiveness ratio of SGD352.52 per QALY relative to SECT alone. DECT seemed a cost-effective strategy at a willingness-to-pay threshold of SGD50 000 per QALY.ConclusionDECT supplementing SECT is a cost-effective imaging strategy to diagnose occult hip fractures among older adults in Singapore and should be included in clinical pathways to expedite timely treatment and considered for reimbursement schemes.     

In vitro modeling accurately predicts cardiac lead fracture at 10 years

1. Download : Download high-res image (166KB)
2. Download : Download full-size image

     

Suzuki's pins and rubber traction for fractures of the base of the middle phalanx

Abstract

Basal fractures of the middle phalanx are uncommon, but difficult to treat. We have reviewed our first 20 patients using the Suzuki pins and rubber traction who were treated during an 8.5 year period (June 1998–December 2006) and 18 who were reviewed after 49 (range 17–116) months. All injuries were closed fractures of the base of the middle phalanx. Ten patients had a fracture of the volar lip and dorsal subluxation of the phalanx, one had a fracture of the dorsal lip, and seven had comminuted pilon fractures. Median operating time was 33 (18–255) minutes. Thick “vessel loops” were often used for traction, and active movement before the traction was removed after 38 (8–46) days was disappointing. There were two superficial infections and one deep. One proximal interphalangeal (PIP) joint had been treated by arthrodesis and another amputated before review. On a visual analogue scale (VAS) from 0 (best) to 10 (worst), patients at review reported discomfort when wearing the traction as 5.5 (0–10), pain as 0 (0–6), and finger function as 3 (0–6). The median Quick-DASH score (100 = worst) was 2 (0–48) and grip strength 97 (75–118) % of the other hand. Median extension, flexion, and total range of movement of the PIP joint in 16 fingers were -9°, 83°, and 72°, respectively. Our results are no more than adequate. They might have been better if the force of traction had been less by using rubber bands instead of vessel loops, if postoperative follow-up had been more frequent allowing for correction of traction when necessary, and if traction had been discontinued earlier.     

Active knee motion after cruciate ligament rupture

In 10 patients with an old injury of the anterior cruciate ligament, the three-dimensional movements of the knee joint were studied when the patients flexed their knees. Tibial motions were recorded using roentgen stereopho-togrammetric analysis. Internal rotation and adduction of the tibia were reduced in the injured knees when compared with the intact knees; during flexion of the knee joint, the tibial intercondylar eminence occupied a more lateral and posterior position on the injured side. Our results may indicate that the knee joint is continuously exposed to abnormal stresses when the anterior cruciate ligament is torn.     

Predisposing factors for chronic syndesmotic instability following syndesmotic fixation in ankle fracture: Minimum 5-year follow-up outcomes

BackgroundThis study aimed to identify risk factors for chronic syndesmotic instability following syndesmotic fixation.MethodsWe performed a retrospective review of consecutive patients who had sustained ankle fractures requiring syndesmotic fixation. Patients available for a minimum 5 years of follow-up were classified into 2 groups according to the presence of syndesmotic instability. Statistical binary logistic regression analyses were performed to investigate the significance of various risk factors. Functional outcomes were assessed using the FAOS.ResultsIn total, 166 patients who met the study inclusion criteria underwent analysis. The overall postoperative instability rate was 20.5%, which was significantly affected due to BMI (p = 0.018; OR 6.72), and concomitant posterior malleolar fracture (p = 0.032, OR 2.77). The mean scores in the syndesmotic instability (SI) group were significantly lower than those in the no syndesmotic instability (NSI) group (p = 0.021).ConclusionsObesity and concomitant posterior malleolar fracture were significant risk factors for postoperative syndesmotic instability.     

Arthroscopy of the Patello-Femoral Joint

Arthroscopy of the knee joint was performed in 126 patients complaining of symptoms in the patello-femoral joint. in about one-third of these cases the arthroscopic findings in the patello-femoral joint were normal, whereas the remainder had varying degrees of chondromalacia or arthrosis. the classification of changes agreed well with an independent classification carried out in conjunction with surgery. in one-third of the cases there were additional findings which could explain the knee symptoms, more than half of these being degenerative changes reminiscent of an early gonarthrosis located in the femuro-tibial joint. There were no complications arising from the arthroscopy procedure which was well tolerated by the patients. It is concluded that arthroscopy is a helpful tool for differential diagnosis in patients with patello-femoral pain and for classification of degenerative changes in this joint.