人工膝关节术后感染的诊断和二期翻修术

目的：对人工膝关节(TKA)术后感染接受二次翻修术的膝关节进行评估。方法：1996年1月～2002年1月实行人工膝关节置换术353膝，其中5个膝关节在术后出现感染，行二期翻修术即一期手术取出原假体，彻底清创，置入抗生素骨水泥间隙垫，术后使用6周以上的敏感抗生素，二期手术作假体翻修术。结果：平均随访2年，无1例翻修的膝关节发生感染或无菌性松动。最近一次随访时平均膝关节功能评分从翻修术前的0分增加到术后的58分(20～100分)，平均膝关节疼痛评分从术前的38分(24～50分)增加到术后的93分(87—100分)。结论：应该尽量采用二期翻修术处理TKA术后感染，以彻底的清除感染灶，使病人获得良好的功能。     

Results of contralateral total knee arthroplasty in patients with a history of stiff total knee arthroplasty

This study seeks to evaluate the clinical outcomes of a second primary total knee arthroplasty in patients whose initial (contralateral) primary total knee arthroplasty was complicated by stiffness. We retrospectively compared the preoperative and postoperative range of motion and Knee Society Scores from a study group of 15 patients with an age-matched control group. Statistical analysis did not reveal a significant difference in final postoperative range of motion or Knee Society Scores between the 2 groups. However, there was a statistically significant higher rate of closed manipulation in the study group. Therefore, although the study group did show a higher rate of early stiffness, eventual functional outcome was comparable with a nonstiffness control group.     

The outcome of sequential repeated tibial tubercle osteotomy performed in 2-stage revision arthroplasty for infected total knee arthroplasty

Thirteen patients with infected total knee arthroplasty treated by 2-stage revision requiring tibial tubercle osteotomy in both stages for extensile exposure were retrospectively analyzed. The preoperative mean range of knee motion improved from 60° (range, 30°-90°) to 94° (range, 70°-120°) at latest follow-up. The Knee Society knee scores and function scores were 39 and 18 preoperatively and 78 and 67 at latest follow-up, respectively. Although proximal migration occurred in 3 cases and a partial proximal avulsion fracture of the osteotomy segment occurred in 1 case after the second-stage reimplantation, radiographic bony union was observed in all cases. Sequential repeated tibial tubercle osteotomy can be a useful extensile surgical approach in staged revision for infected total knee arthroplasty with satisfactory clinical and radiographic outcomes.     

Outcomes of total hip and knee arthroplasty after cardiac transplantation

The outcomes of 18 primary or revision total hip (THA) and knee arthroplasties (TKA) in 9 patients with cardiac transplants were reviewed. Primary total joint arthroplasties were performed for osteonecrosis (5 hips) or osteoarthritis (5 hips, 4 knees). There were no infections in any of these patients. Final Harris Hip Scores were 71.8 for patients with osteonecrosis and 88.6 for osteoarthritis. Eight of 10 hips were pain-free at final follow-up. Two of the 10 primary THAs required late revision at 7 and 10 years after the index arthroplasty. One patient (2 hips and 1 knee) had chronic bilateral lower extremity pain. Total knee arthroplasty range of motion averaged from 7.5° to 118°. Average final Knee Society function score was 79, and objective score was 88. One of 4 patients with primary TKA required a manipulation under anesthesia. No reoperations were required in this group. Overall, patients with heart transplantations on immunosuppression had generally good pain relief after THA and TKA. There were no infections in this small cohort; however, there were many complications.     

髌骨合理设计在全膝关节置换中的临床效果

目的探讨髌骨合理设计后重塑在全膝关节置换(TKA)中的临床效果。方法根据股骨假体滑动轨迹及所需置换髌骨的形态,对56例TKA患者(72膝)术中进行髌骨合理设计并重塑,观察患者术后的关节活动度及疼痛情况,用KSS膝关节评分系统评定治疗效果。结果 56例均获得随访,时间6~18个月。仅1例患者膝关节活动度70°,活动较差,但疼痛明显减轻;其余患者屈曲活动度在0°~110°。KSS评分:优69膝,良2膝,中1膝,优良率达到98.6%。结论术中根据股骨假体滑动轨迹对髌骨合理设计并重塑,可以使未进行髌骨置换的TKA患者取得满意的治疗效果。     

High Rate of Local Recurrence and Complications Following Total Knee Arthroplasty in the Setting of Synovial Chondromatosis

Background

Synovial chondromatosis is a rare, monoarticular arthropathy due to synovial metaplasia. There is a paucity of data examining the outcome of total knee arthroplasty (TKA) in the setting of synovial chondromatosis. The purpose of this study is to investigate the outcome and function in patients undergoing TKA for management of synovial chondromatosis.

Midterm results of all-polyethylene tibial components in primary total knee arthroplasty

Our goal was to determine the 7-year survivorship of a total knee arthroplasty system with all-polyethylene tibial components. From June 1996 to December 1997, 129 consecutive patients (177 knees) (>/=70 years old) underwent such primary arthroplasty at 2 centers in the United States. The 88 patients (120 knees) with 7 years or more of follow-up were evaluated radiographically and functionally. Average results included: Knee Society Score, 93.7 points (SD, 8.1); Knee Society function score, 68.9 points (SD, 27.6); range of motion, 119 degrees (SD, 10.9); osteolysis, 0%; stress shielding, 6.6%; progressive radiolucencies, 2.5%; Kaplan-Meier survivorship (revision), 99.4% (95% confidence intervals, 98.2%-100.0%). At midterm follow-up, an all-polyethylene tibial component proved to be an excellent surgical option for total knee arthroplasty in an elderly patient population.     

Impact of modified-release opioid use on clinical outcomes following total hip and knee arthroplasty: a propensity score-matched cohort study

Modified-release opioids are often prescribed for the management of moderate to severe acute pain following total hip and knee arthroplasty, despite recommendations against their use due to increasing concerns regarding harm. The primary objective of this multicentre study was to examine the impact of modified-release opioid use on the incidence of opioid-related adverse events compared with immediate-release opioid use, among adult inpatients following total hip or knee arthroplasty. Data for total hip and knee arthroplasty inpatients receiving an opioid analgesic for postoperative analgesia during hospitalisation were collected from electronic medical records of three tertiary metropolitan hospitals in Australia. The primary outcome was the incidence of opioid-related adverse events during hospital admission. Patients who received modified with or without immediate-release opioids were matched to those receiving immediate-release opioids only (1:1) using nearest neighbour propensity score matching with patient and clinical characteristics as covariates. This included total opioid dose received. In the matched cohorts, patients given modified-release opioids (n = 347) experienced a higher incidence of opioid-related adverse events overall, compared with those given immediate-release opioids only (20.5%, 71/347 vs. 12.7%, 44/347; difference in proportions 7.8% [95%CI 2.3–13.3%]). Modified-release opioid use was associated with an increased risk of harm when used for acute pain during hospitalisation after total hip or knee arthroplasty.     

Initial results of managing severe bone loss in infected total joint arthroplasty using customized articulating spacers

Twenty-three cases of infected total joint arthroplasty with substantial bone loss were treated with a cement spacer, which was customized intraoperatively to achieve joint stability and to allow motion. All but one of the patients were ambulatory with the spacer in place. Spacer dislocation occurred in 1 hip patient (9%) and in none of the knee patients. Articulating antibiotic-impregnated spacers with intraoperative customization is our preferred treatment of cases of infected total joint arthroplasty even in the presence of bone loss.     

Surgeon Decision-Making for Individuals With Obesity When Indicating Total Joint Arthroplasty

BackgroundObesity is a risk factor for complications after total joint arthroplasty (TJA). This study analyzed the impact of individual surgeon demographics, financial concerns, and other factors in determining patient candidacy for TJA based on body mass index (BMI).MethodsA 21-question survey was approved by the American Association of Hip and Knee Surgeons Research Committee for distribution to its membership. Objective questions asked about surgeon or hospital BMI thresholds for offering TJA. Subjective questions asked about physician comfort discussing topics including obesity, bariatric surgery, and weight loss before TJA, as well as insurance and age considerations.ResultsFor TJA procedures, 49.9% of surgeons had a BMI cutoff at 40, 24.5% at 45, and 8.3% at 50. At a BMI cutoff of 40, 23.8% of surgeons felt their patient volume would be adversely affected, whereas at a BMI cutoff of 35, 50% of surgeons felt their patient volume would be adversely affected. Surgeons were more likely to not perform total hip arthroplasty on patients with morbid obesity than total knee arthroplasty (P = .037). Significantly more academic surgeons did not have cutoffs for total hip arthroplasty (P = .003) or total knee arthroplasty (P < .001) compared with all other practice settings.ConclusionThere are myriad factors that affect surgeon BMI thresholds for offering elective TJA including poor outcomes, hospital thresholds, financial considerations, and the well being of the patient. Further work should be performed to minimize the risks associated with TJA while providing the best possible care to patients with morbid obesity.     

Revision surgery for patellar dislocation after primary total knee arthroplasty

This study evaluated risk factors for patellar dislocation after primary total knee arthroplasty and determined functional outcomes in patients following revision. Thirty-nine knees in 39 patients averaging 68 years (range, 27-91 years) at the time of revision were evaluated at a mean of 3.2 years (range, 2-7 years). Mean Knee Society and Function scores significantly improved from 34 and 35 to 77 and 54, respectively. Patellar dislocation most commonly resulted from errors in technique such as soft-tissue imbalance and malaligned components that led to poor tracking of the patella. Patellar tracking only improved after soft-tissue realignment in combination with revision of malaligned or loose components. Although revision significantly improved active knee extension and Knee Scores, two thirds of the patients had residual disabilities and pain.     

Total knee arthroplasty for post-traumatic arthrosis

The outcomes of total knee arthroplasty for post-traumatic arthrosis were studied in 31 knees. The average age at arthroplasty was 60 years old (range, 36-78 years). The interval from fracture to total knee arthroplasty averaged 13 years. Simultaneous corrective osteotomy was necessary in 4 patients to correct axial alignment and preserve ligamentous integrity. Follow-up averaged 46 months. Mean arc of motion increased significantly, from 94 degrees to 100 degrees (P = .027). Average function score improved from 44 to 72 points. This change was statistically significant (P<.0001). Knee Society knee scores also improved significantly, from 36 to 78 points (P<.0001). At most recent follow-up, the functional scores were considered excellent or good in 58%; knee scores were considered excellent or good in 71% of cases. All periarticular osteotomies and tibial tubercle osteotomies healed uneventfully within 16 weeks. Complications occurred in 57% of cases, including aseptic failure (26%), septic failure (10%), patellar tendon rupture (3%), patellar subluxation (6%), thromboembolism (6%), and wound breakdown requiring debridement and muscle flap coverage (6%). Despite significant improvements in motion and function, patients with post-traumatic arthrosis are susceptible to high rates of complications. Adverse outcomes can be minimized by restoring limb alignment, soft tissue balance, and component alignment and by preserving vascularity of the skin and subcutaneous tissues.     

No Major Functional Benefit After Bicompartmental Knee Arthroplasty Compared to Total Knee Arthroplasty at 5-Year Follow-Up

BackgroundIn case of isolated medial and patellofemoral joint arthritis, bicompartmental knee arthroplasty (BCA) is an alternative to total knee arthroplasty (TKA). The purpose of our prospective, randomized study is to compare the clinical outcome of BCA vs TKA.MethodsEighty patients with isolated medial and patellofemoral osteoarthritis were randomly assigned to either BCA or TKA. Patients were evaluated preoperatively, 3, 6, and 12 months, and 2 and 5 years after the procedure. Knee Society Score, Oxford Knee Score, and the University of California,Los Angeles activity scores were calculated at each follow-up; Forgotten Joint Score was assessed at final follow-up.ResultsThere was an improvement in Knee Society Score, Oxford Knee Score, and the University of California,Los Angeles scores in both groups but no significant differences between both groups at any follow-up. The Forgotten Joint Score at 5-year follow-up was not significantly different either. Range of motion was significantly greater in the BCA group from 1-year follow-up onward.ConclusionOur study did not show significant differences in clinical scores between BCA and TKA; only range of motion was significantly greater in BCA. Therefore, it is questionable whether this difference justifies the complexity of BCA associated with higher risk of failure. Maybe staged patellofemoral joint arthroplasty in the presence of a well-functioning UKA is an option for BCA and an alternative to revision to TKA. Long-term studies are needed to explore the potential benefits of BCA.     

Early clinical results of a high-flexion, posterior-stabilized, mobile-bearing total knee arthroplasty: a US investigational device exemption trial

Between May 2001 and June 2004, 388 total knee arthroplasty cases were enrolled in a prospective, randomized, multicenter investigational device exemption trial. Patients received either the investigational high-flexion mobile-bearing knee or a fixed-bearing control. At 2 to 4 years of follow-up, results in 293 patients with degenerative joint disease were compared using Knee Society Assessment and Function scores, radiographic results, complications analysis, and survival estimates. The mobile-bearing and fixed-bearing groups demonstrated similar, significant improvement over preoperative assessments in Knee Scores, maximum flexion, and range of motion. One mobile-bearing arthroplasty required revision. Radiographic results were unremarkable, and implant-related complications were rare in both groups. At this early follow-up, the investigational high-flexion mobile-bearing knee and its fixed-bearing counterpart demonstrated comparable, effective performance.     

Lateral retinacular release during primary total knee arthroplasty: effect on outcomes and complications

Intraoperative lateral retinacular release performed during primary total knee arthroplasty (TKA) can improve patellar tracking. This study compares the outcomes of patients who did and did not have lateral retinacular release during primary TKA. One thousand one hundred eight consecutive primary TKAs were reviewed. Lateral release was performed on 314 patients; 794 patients did not undergo release. Comparisons of range of motion, Knee Society Score, and postoperative complications were made between the 2 groups. At an average follow-up of 4.7 years, no statistically significant difference in range of motion, Knee Society Score, or postoperative complications of patella fracture, subluxation, postoperative manipulation, or wound complications was demonstrated. Lateral retinacular release to achieve improved patellar tracking does not compromise the clinical outcomes or complication rate of primary TKA.     

Bone Mineral Density in the Proximal Femur and Contralateral Knee After Total Knee Arthroplasty

Osteoarthrosis (OA) is often associated with pain and disability, which are relieved after total knee arthroplasty (TKA), but the nature of bone changes associated with OA is controversial. We examined preoperative hip and contralateral knee bone mineral density (BMD) in patients requiring TKA and monitored the BMD changes postoperatively. Sixty-nine patients, scheduled to have TKA for osteoarthrotic knees, had both hips and contralateral knee BMD measured by dual-energy X-ray absorptiometry (DXA) at the time of operation (baseline) and at 1 yr after operation. X-rays of the knee joints were also taken to evaluate the severity of OA. Preoperatively, 27% and 38% of the patients had total hip BMD Z-score more than 1 SD in the operated side and contralateral hips, respectively. In all regions of interest (ROI), the mean baseline BMD of the affected side proximal femur was significantly lower than that of the contralateral side (p < 0.0005-0.019). The severity of OA was not associated with BMD. During 1-yr follow-up, the postoperative knee status and the physical activity of the patients (AKS score) improved. However, neither the hip nor the nonoperated knee BMDs increased. Knee OA is associated with significantly lower BMD values in the affected side compared with the contralateral hip, and these levels remained similar or decreased during a 1-yr follow-up. We conclude that improved mobility after TKA does not improve the effects of preoperative disuse-associated bone loss in the short term.     

Total Joint Arthroplasty: Should Patients Have Preoperative Dental Clearance?

Obtaining dental clearance prior to elective total joint arthroplasty is a common practice; however, little published data exist to justify this requirement. Dental clearance data for 365 elective total knee and total hip arthroplasty patients were gathered prospectively. Of these patients, 358 (average age of 62.4 years; 157 men and 201 women; 152 primary total knee arthroplasties (TKAs), 16 revision TKA arthroplasties, one conversion TKA, 168 primary total hip (THAs) arthroplasties and 21 revision THA arthroplasties) proceeded to surgery and follow-up data were available for 355. A comparison group of 218 hip fracture patients (average age of 78.7 years; 52 men and 109 women; 137 THA and 81 hemiarthroplasties) with no preoperative dental clearance who were treated with hip arthroplasty was extracted retrospectively from an institutional database. Follow-up data were available for 161 of these patients. The incidence of dental pathology in the elective arthroplasty group was 8.8%. Early postoperative infection requiring surgical treatment occurred in six patients (1.7%) in the dental clearance elective arthroplasty group and in four patients (2.5%) in the hip fracture arthroplasty group. No statistical difference was found between the two groups. This suggests that the perceived need for routine preoperative dental screening for all hip and knee arthroplasty patients should be reassessed.