Long-Term Outcome on the Mal-Seating of Ceramic-on-Ceramic Articulation in Total Hip Arthroplasty.

BACKGROUND: Total hip arthroplasty with ceramic-on-ceramic articulation aims to decrease wear, osteolysis, and aseptic loosening. A metal-backed ceramic liner was developed to reduce the risk of liner fracture. However, a significant number of cases of mal-seating of the metal-backed ceramic liner were observed in the 2000s, and there were concerns about their outcome. This review aims to investigate the long-term performance of the mal-seated ceramic liner. METHODS: From July 2003 to March 2007, 35 ceramic-on-ceramic total hip arthroplasties were performed with the Trident acetabular system. Clinical assessment, radiological analysis, and outcome assessment were performed. The prevalence of liner mal-seating and its long-term outcomes were investigated. RESULTS: There was liner mal-seating in 8 hips (22.9%). One liner was exchanged in the early postoperative period. No revision surgery was required for the remaining 7 hips at a mean follow-up of 14 years. All patients were free of hip pain with a mean Harris Hip Score of 94.7 at the most recent follow-up. No adverse event was observed. CONCLUSION: The long-term outcomes of the mal-seated liner were favorable. However, surgeons should exercise meticulous surgical technique to achieve a properly aligned liner within the acetabular shell to minimize this potentially correctable error.

Satisfactory long-term survival, functional and radiological outcomes of open-wedge high tibial osteotomy for managing knee osteoarthritis: Minimum 10-year follow-up study.

BACKGROUND: This prospective cohort study was designed to evaluate the survivorship and functional outcomes associated with long-term results of medial open-wedge high tibial osteotomy (MOWHTO) for the treatment of medial compartment knee osteoarthritis in the Chinese population. Although MOWHTO is a well-established procedure in the management of medial osteoarthritis of the knee, the long-term outcome in the Chinese population has not been reported in current literature. We hypothesised that MOWHTO would result in long-term preservation of knee function in Chinese, similar to that reported in the Caucasian population. METHODS: A cohort of 22 young adult patients (age < 55 years old) undergoing MOWHTO for the treatment of symptomatic medial compartment knee osteoarthritis between 2002 and 2008 was retrospectively surveyed with a minimum follow-up of 10 years. Kaplan-Meier survival analysis was performed, and the failure modes were investigated. The outcomes on survival (not requiring arthroplasty), clinical outcome (Knee Society Knee Score and Knee Society Function Score) and range of motion (numeric rating scale) at preoperative, 1-year postoperative follow-up and at last follow-up (>10 years) were evaluated. In addition, the mechanical tibiofemoral angle was also measured. The Wilcoxon signed-rank test was used for statistical evaluation of nonparametric data in these related samples. RESULT: A total of 31 knees in these 22 cases were included. The follow-up rate was 100% at 13.4 ± 1.9 years (11-17). Mean age at time of surgery was 45.8 ± 9.5 years (18-53). At 10-year follow-up, four knees converted to require total knee arthroplasty (survival: 87.1%). Preoperative varus alignment with mechanical tibiofemoral angle of -9.26 ± 2.83 was corrected to 2.58 ± 2.46 after surgery and remained 2.01 ± 3.52 at the latest follow-up. Knee Society Knee Score increased significantly from 53.7 ± 11.1 preoperatively to 93.8 ± 6.8 at 1-year follow-up and 91.8 ± 9.7 at latest follow-up. Similarly, the functional score also increased significantly from 67.4 ± 21.0 preoperatively to 86.3 ± 14.5 at 1-year follow-up and 82.1 ± 16.6 at latest follow-up (p < 0.01). Whereas, the range of motion significantly decreased from 122.7 ± 6.6 preoperatively to 116.1 ± 15.5 at the latest follow-up. CONCLUSION: Even in cases of severe medial osteoarthritis and varus malalignment, MOWHTO would be a good treatment option for management in active Chinese population less than 55 years. Although the long-term survival and functional outcome after MOWHTO was proven to be satisfactory in our cohort during the 10-year follow-up, a larger cohort to illustrate the long-term functional outcome is still warranted. TRANSLATIONAL POTENTIAL: The finding in this study indicated MOWHTO is a feasible treatment option for young adult patients with osteoarthritis to achieve long-term satisfactory results.

Prospective randomized trial comparing efficacy and safety of intravenous and intra-articular tranexamic acid in total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is associated with significant perioperative blood loss and postoperative allogenic blood transfusion. Tranexamic acid (TXA) reversibly blocks lysine binding sites on plasminogen molecules and inhibits plasmin formation. Comparisons of the efficacy and safety of intra-articular and intravenous TXA in primary TKA have not previously been reported. METHODS: A prospective randomized trial was conducted in 150 patients who underwent TKA, and these patients were randomized into three groups. Patients in Group A were injected by intra-articular TXA according to body weight (20 mg/kg). Patients in Group B received a standard dose of intra-articular TXA (2000 mg), and those in Group C were infused with TXA according to body weight (20 mg/kg) before tourniquet deflation and again 3 h later. Baseline characteristics and data collected at blood transfusion were compared. Differences among four time points (baseline, day 0, day 2, and day 5) were carried out using ANOVA. RESULTS: The hemoglobin levels at postoperative day 5 were 10.6 g/dL for Group A, 10.6 g/dL for Group B, and 10.7 g/dL for Group C. The drain output was 399 ml for Group A, 314 ml for Group B, and 305 ml for Group C (p = 0.03). Group C had significantly less drain output than Group A after post hoc comparisons (p = 0.05), whereas no significant difference was observed between Group A and B (p = 0.09) or between Group B and C. CONCLUSION: The weight-adjusted dose of TXA administered intravenously significantly reduced the drain output but not the total blood loss when compared with the weight-adjusted dose of TXA administered intra-articularly. No significant difference was observed in the other parameters among the three groups. TRIAL REGISTRATION: The Joint CUHK-NTEC CREC, CRE-2013.644-T . Registered 1 March 2014.

Mycobacterium chelonae infection after total knee arthroplasty: a case report.

We present a case of Mycobacterium chelonae infection after total knee arthroplasty in a 70-year-old woman. The patient underwent implant removal, drainage, debridement, and insertion of a gentamycin-load cement spacer. After 4 months, the second-stage surgery was performed. Intravenous amikacin (6 weeks) and oral clarithromycin (12 weeks) were given. At the 12-month follow-up, the patient achieved 90 degrees of flexion and could walk with a stick for up to 15 minutes. She was not taking any analgesics.

Exeter small femoral stem for patients with small femurs.

PURPOSE: To report the long-term results of total hip arthroplasty (THA) using small size Exeter femoral stems. METHODS: Eight men and 34 women aged 60 to 83 (mean, 70) years underwent 45 THAs using the Exeter small stem with offsets of 30 mm (n=3), 33 mm (n=15), and 35.5 mm (n=27). The Harris hip score was assessed pre- and post-operatively. Stem alignment and axial subsidence of the stem were measured. Radiolucent lines around the femur were recorded at 14 Gruen zones. Completeness and thickness of the cement mantle and cement fractures were also noted. Ectopic ossification, if present, was graded. Stem loosening was based on the Olsson definitions. RESULTS: The mean follow-up was 9 (range, 5-12) years. The mean Harris hip score improved from 37 (range, 13-61) to 80 (range, 47-96) [p<0.001]. At the latest follow-up, the score was excellent (90-100) in 8 (18%) of the hips, good (80-89) in 21 (47%), fair (70-79) in 9 (20%), and poor (<70) in 7 (16%). All hips had a complete cement mantle of 2 mm or more. All stems were inserted without intramedullary reaming. 11 (24%) of the hips developed stem subsidence of <2 mm; all stabilised within 2 years. None of these patients had pain or other radiological signs of loosening. Six stems showed radiolucent lines of <1 mm in the upper zones, which were not progressive. No cement fracture or subsidence was noted. Using revision for any cause as an endpoint, the overall survival rate of Exeter small femoral stem was 100% at 10 years and 89% at 12 years. CONCLUSION: The results of Exeter small stems for patients with small femurs are good.

Osteoradionecrosis of the acetabulum in a total hip arthroplasty: a case report.

Osteoradionecrosis is a rare complication of radiation therapy. The pelvic and facial bones are those most likely to be affected when radiotherapy is used to manage gynaecological or nasopharyngeal malignancies. We report a 78-year-old woman with osteoradionecrosis of the acetabulum in a total hip arthroplasty 4 years after radiotherapy for a carcinoma of the vagina. Osteolysis of the acetabulum with pelvic discontinuity was noted on radiographs, but the patient was asymptomatic.

Ceramic insert dislodgment after revision ceramic-on-ceramic total hip arthroplasty.

We present a case of early ceramic insert dislodgment in a young patient with revision uncemented ceramic-on-ceramic total hip arthroplasty. The presentation may be subtle and the dislodgment may go unnoticed. This incidence draws our attention to the need for careful intraoperative confirmation of the insert position and frequent serial radiographic monitoring. The case also draws speculation of possible design flaws in the locking mechanism predisposing for the insert dislodgment.

Computer assisted pelvic tumor resection and reconstruction with a custom-made prosthesis using an innovative adaptation and its validation.

Computer aided musculoskeletal tumor surgery is a novel concept. Ideally, computer navigation enables the integration of preoperative information concerning tumor extent and regional anatomy to facilitate execution of a surgical resection. Accurate resection helps oncological clearance and facilitates precise fitting of a custom prosthesis. We adapted a commercially available computer navigation platform for spine, and used it to plan and execute pelvic bone resection and custom pelvic prosthetic reconstruction in a patient with a metastatic tumor affecting the acetabulum. The surgery was simulated and validated using a plaster bone model based on the patient's preoperative CT data, before performing the procedure on the patient.

Early failure of smooth hydroxyapatite-coated press-fit acetabular cup--7 years of follow-up.

The early results of smooth hydroxyapatite-coated press-fit acetabular cup are comparable to porous-coated press-fit cup, but these results deteriorate dramatically after 5 years. In this study, 66 primary total hip arthroplasties performed between 1994 and 1998 were reviewed. The average follow-up was 6.5 years. Of the 66 arthroplasties, 8 acetabular cups were revised for aseptic loosening presenting as rapid change of cup position. The average duration of symptoms before revision was 3 months. The survival of the cups at 5 and 9 years were 95.4% and 83%, respectively. The rapid clinical deterioration after 5 years may be due to lack of bone ingrowth into the cup making it unable to resist the shearing stress in the acetabulum. Radiolucent line was not an accurate sign for the detection of mechanical failure.

Primary exeter total hip arthroplasty in patients with small femurs: a minimal of 10 years follow-up.

One hundred and twelve hips in 101 Chinese patients received primary cemented Exeter total hip arthroplasty (Howmedica, Hong Kong). The implant had a collarless, double-tapered and polished stem. Seventy-five hips in 67 patients were available for assessment. The average age at operation was 63.7 years. The commonest diagnosis was avascular necrosis. The average follow-up was 12.8 years (range, 10 to 16.5 years). The Harris score improved from a preoperative average of 39.8 to 82.3 at the last follow-up. Stem subsidence within the cement mantle occurred in 9.3% of the cases and none of these stems had other evidence of loosening. Eight hips (six stems and two cups) in seven patients were revised because of loosening at five to 14 years postoperatively. The survival rate was 93.3% and 86% at 10 and 15 years respectively. Oversized stems and incomplete cement mantle might account for the loosening. Stems of a smaller size have been made available to this population and hopefully this will improve the results further.