Patellar resurfacing versus no resurfacing in two-stage revision of infected total knee arthroplasty.

BACKGROUND: Cartilage debridement and staged reimplantation are the most common treatments for infected total knee arthroplasty (TKA). Very few studies have focused on the management of primarily non-resurfaced patellae in infected TKA. The purpose of this study was to compare the outcomes of patellar resurfacing and non-resurfacing in two-stage revision of infected TKA. METHODS: This study involved a retrospective comparison of the reinfection rate and clinical outcomes of revision TKA patients managed with patellar resurfacing (22 patients, 23 knees) and patients managed without patellar resurfacing (26 patients) at a minimum two-year follow-up. The mean age in the resurfacing group was 69.4years old, and the mean age in the non-resurfacing group was 67.3years old. Three scales were used in the assessment: the Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, and the Anterior Knee Pain Scale. RESULTS: Three knees had recurrent infections. All infections occurred in patients who had received patellar resurfacing. There were no significant differences between groups in clinical results and on the Anterior Knee Pain Scale. A lack of patellar resurfacing did not increase recurrence of infection and did not result in significant clinical differences compared to patellar resurfacing. CONCLUSIONS: This study indicates that preservation of the original patellar bone is a feasible option for patellar management in revision of septic TKA. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Evaluation of the alpha angle in asymptomatic adult hip joints: analysis of 994 hips.

INTRODUCTION: Numerous studies on cam femoroacetabular impingement (FAI) causing osteoarthritis have been conducted in Western populations, but not in Asian populations. The alpha angle in cam type FAI can be measured by routine hip AP and axial radiographs. The purpose of this study was to determine the range of alpha angles in an asymptomatic Asian cohort. MATERIALS AND METHODS: We performed a retrospective examination on 500 asymptomatic Asian adults (1000 hips) who underwent simultaneous spine MRI and hip coronal survey MRI for evaluation of back pain from December 2009 to March 2010. The alpha angle was measured on anteroposterior (AP) pelvic survey images. According to inclusion criteria, 372 hips of 186 men and 622 hips of 311 women were analysed. RESULTS: The mean alpha angles for men and women were 50.61° ± 7.61° and 49.82° ± 4.14°, respectively with no statistically significant differences (p = 0.063). Alpha angles of the two age groups (≥50 years old and <50 years old) were similar in both genders: 49.90° ± 6.88° versus 51.40° ± 8.30° in men (p = 0.060), and 50.61° ± 7.61° versus 49.82° ± 4.14° in women (p = 0.71). The frequency of pathologic alpha angle of men and women was 0.5% and 3.1%, respectively. CONCLUSIONS: After review of 994 asymptomatic adult hips, we found neither gender-specific nor age-specific differences in the alpha angle. The frequency of the pathological range of the alpha angle was notably rare, as compared to those of Western countries. We assume that these findings could be related to a low prevalence of FAI and idiopathic osteoarthritis of the hip in the Asian population.

Periacetabular osteolysis is the problem in contemporary total hip arthroplasty in young patients.

We retrospectively reviewed 474 patients (492 hips) with a contemporary cemented total hip arthroplasty (THA) (mean age, 38.9 years) and 504 patients (532 hips) with a cementless THA (mean age, 39.3 years). Patients were evaluated clinically and radiographically. The mean follow-up was similar (14.5 vs 14.8 years) in both groups. The mean postoperative Harris hip scores (93.6 vs 94.7 points), the mean Western Ontario and McMaster Universities Osteoarthritis Index scores (12 vs 13 points), and the mean University of California, Los Angeles activity scores (6.9 vs 7.1 points) were similar between the 2 groups. Incidence of acetabular osteolysis (16% vs 20%) and femoral osteolysis (8% vs 9%) was similar between the 2 groups. Survivorship of cup (86% vs 82%) and stem (98% vs 98.5%) was similar between the 2 groups. Periacetabular osteolysis constitutes the major challenge in modern THAs in young patients.

Is hydroxyapatite coating necessary to improve survivorship of porous-coated titanium femoral stem?

We compared the clinical and radiologic results in 55 patients (110 hips) associated with proximally porous-coated titanium stems that were identical in geometry but differed with regard to proximal surface treatment (with or without hydroxyapatite coating). The mean age at the time of the operation was 46.3 years (27-63 years), and mean length of follow-up was 15.6 years (15-16 years). The mean Harris hip score in both groups improved from 39 points and 41 points, respectively, to 93 and 91 points, respectively, at the last follow-up. After 16 years, the cumulative survival for the stem was 100% in both groups and for the cup was 89% in both groups. After long-term follow-up, hydroxyapatite coating on the porous surfaces did not improve or diminish the results of total hip arthroplasty.

A prospective short-term outcome study of a short metaphyseal fitting total hip arthroplasty.

The purpose of this study was to determine whether the short, metaphyseal fitting femoral stem would achieve stable fixation without diaphyseal fixation. A total of 126 patients (144 hips) were included in the study, and their mean age was 53.9 years (26-65 years). The mean duration of follow-up was 4.5 years (4-5 years). The predominant diagnosis was osteonecrosis of femoral head (88 of 144 hips, or 61%). The mean preoperative Harris hip score was 45 points, which improved to 96 points by the final follow-up. Western Ontario and McMaster Universities Osteoarthritis score and patient's activity score were improved substantially at the final follow-up. This short, metaphyseal fitting cementless femoral component achieved stable fixation without diaphyseal fixation, and there was minimal stress-shielding bone resorption in the calcar region.

Contemporary total hip arthroplasty with and without cement in patients with osteonecrosis of the femoral head: a concise follow-up, at an average of seventeen years, of a previous report.

We previously evaluated ninety-eight consecutive patients (148 hips) at mean of 9.3 years after total hip arthroplasty; the mean age at the time of the index surgical procedure was 47.3 years. Fifty patients (100 hips) had simultaneous bilateral arthroplasty with a cemented stem in one hip and a cementless stem in the contralateral hip. Forty-eight patients (forty-eight hips) had unilateral hip arthroplasty with a cementless stem. All patients had a cementless acetabular component. In our first report, we found no difference in clinical results, as measured with the Harris hip score and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), between the cementless and cemented stems. One hip (2%) in the hybrid group (a cementless cup and a cemented stem) had revision because of infection and two hips (2%) in the fully cementless group had revision of the femoral component because of a periprosthetic fracture. Between the time of follow-up in that study (at a mean of 9.3 years) and the time of follow-up in the present study (at a mean of 17.3 years), twenty-two revisions of acetabular components were performed, with eight in the hybrid group and fourteen in the fully cementless group. There was no difference in clinical results, as measured with the Harris hip score and the WOMAC, between the hybrid and fully cementless groups. At the time of the present review, forty (83%) of forty-eight acetabular components in the hybrid group and eighty (85%) of ninety-four acetabular components in the fully cementless group were intact. Most of the femoral components (98%) in both groups were intact. Wear and periacetabular osteolysis were the causes of failure in the hips requiring revision.

Is intra-articular multimodal drug injection effective in pain management after total knee arthroplasty? A randomized, double-blinded, prospective study.

We performed a prospective, double-blinded, randomized, and controlled study to assess the clinical efficacy and safety of intra-articular multimodal drug injection after total knee arthroplasty. Two hundred eighty-six patients undergoing simultaneous bilateral total knee arthroplasty were randomized to receive the injection of multimodal drugs in one knee and normal saline solution as a placebo in the contralateral knee. All patients received patient-controlled analgesia for 48 hours after surgery, followed by standard analgesia. Visual analog scores for pain during activity and rest and for patient satisfaction were recorded. The range of motion and blood loss were also recorded. Intraoperative intra-articular injection of multimodal drugs into the knee did not improve patient pain and satisfaction, range of motion, or blood loss compared with the placebo control.

Comparison of the low contact stress and press fit condylar rotating-platform mobile-bearing prostheses in total knee arthroplasty: a prospective randomized study.

BACKGROUND: To our knowledge, no study to date has compared the clinical results of posterior cruciate-sacrificing mobile-bearing total knee replacements with those of posterior-stabilized mobile-bearing total knee replacements in the same patients. The purpose of the present study was to compare the clinical and radiographic results of these two designs. We hypothesized that the results would be better for knees treated with the posterior-stabilized mobile-bearing prosthesis. METHODS: The present study consisted of a consecutive series of 107 female patients (mean age, 66.8 years) who underwent bilateral simultaneous total knee arthroplasty at the same surgical setting. All of these patients received a posterior cruciate-sacrificing mobile-bearing prosthesis in one knee and a posterior-stabilized mobile-bearing prosthesis in the contralateral knee. At the time of each follow-up (mean, 7.4 years; range, seven to 7.6 years), the patients were assessed clinically. RESULTS: The mean postoperative Knee Society knee score (96 compared with 97 points) and Hospital for Special Surgery knee score (93 compared with 94 points) were similar between the two groups. At the time of the latest follow-up, the average range of motion was 127.7° (range, 70° to 150°) in the knees with a posterior cruciate-sacrificing mobile-bearing prosthesis and 132.4° (range, 90° to 150°) in the knees with a posterior-stabilized mobile-bearing prosthesis. With a margin of error of the manual measurement of 5°, this difference was not significant. The estimated survival rate was 97.2% (95% confidence interval, 91% to 99%) at seven years in the posterior-cruciate sacrificing mobile-bearing prosthesis group and 98.1% (95% confidence interval, 92% to 99%) at seven years in the posterior-stabilized mobile-bearing prosthesis group. CONCLUSIONS: After a minimum duration of follow-up of seven years, we found no significant differences between the two groups with regard to the clinical and radiographic results, including knee range of motion.

Diagnostic dilemma of tuberculosis in the foot and ankle.

BACKGROUND: Isolated involvement of bone in tuberculous infection is uncommon, and the variable clinical and radiological features may mimic pyogenic osteomyelitis, bone tumor or other inflammatory and neoplastic processes of the synovium. We have reported our experiences with the diagnosis of tuberculosis infection in the ankle and foot with the hope of providing sufficient information about these cases to lead to early diagnosis. MATERIALS AND METHODS: We treated 15 patients with tuberculosis involving the foot and ankle between 1995 and 2005. They were followed for a minimum of 24 months, and the average duration of symptoms was 23 months. All patients underwent a physical examination, routine laboratory tests, plain radiographs, and a biopsy of the infection site. MRI studies were performed in 10 patients and a CT scan was done in one patient. RESULTS: The lesions were located in the forefoot (2), midfoot (3) and ankle (10). From the imaging studies, the presumptive preoperative diagnoses were tuberculous osteomyelitis (7), pyogenic osteomyelitis (4), pigmented villonodular synovitis (2), amyloidosis (1), and avascular necrosis of the talus (1). These diagnoses were verified by granulomatous inflammation with or without caseous necrosis on histology and tubercle bacilli were cultured in four cases. In three cases the diagnosis was made by polymerase chain reaction (PCR). CONCLUSION: When a patient presents with a localized, painful swelling and a persistent draining sinus of the foot and ankle, tuberculosis should be considered in the differential diagnosis. Additionally, we highly recommend taking a biopsy of the site of suspected infection because an early diagnosis is the key to successful treatment.