Treatment of the exposed knee prosthesis

Background and purpose — There are still controversies as to the age for beginning treatment with the Ponseti method. We evaluated the clinical outcome with different age at onset of Ponseti management for clubfoot.

Patients and methods — 90 included children were divided into 3 groups in terms of age at start of treatment. The difference in treatment-related and prognosis-related variables including presentation age, initial Pirani and Dimeglio score, casts required, relapse rates, final Dimeglio score, and international clubfoot study group score (ICFSG) was analyzed.

Results — Age between 28 days and 3 months at start of treatment method was associated with fewer casts required, lower relapse rate, and lower final ICFSG score (p < 0.05). Early treatment before 28 days of age required more casts and had a higher relapse rate (p < 0.05). The highest ICFSG scores were found in the ages between 3 and 6 months (p < 0.05). After propensity score matching, age between 28 days and 3 months was demonstrated to have a lower finial ICFSG score. Linear regression models showed that presentation age was positively correlated with final ICFSG score, and was identified as the only independent prognostic risk factor.

Interpretation — There was lower rate of relapse and better clinical outcome when treatment was initiated at age between 28 days and 3 months. With the Ponseti method, clubfeet may not need urgent treatment.     

Treatment of the exposed knee prosthesis

Ten knees with early tissue breakdown after knee arthroplasty resulting in exposed prostheses were treated with different plastic surgical techniques. Six knees were successfully covered: four using a gastrocnemius musculocutaneous flap, one using a fasciocutaneous flap, and one using split-skin grafts. Four knees failed: two using local skin flaps and two using split-skin grafts.

A gastrocnemius musculocutaneous flap seems to provide a reliable coverage of the exposed knee joint.     

Soft tissue cover for the exposed knee prosthesis

 This study assess the use of muscle flaps to cover exposed knee prostheses and emphasises the need for early plastic surgery consultation. In five of the six patients studied the wound was successfully covered and the knee prosthesis salvaged with a reasonable functional outcome.

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Résumé  Cette étude montre l’intêret des lambeaux musculaires pour couvrir les prothèses de genou exposées, et insiste sur la necessité d’une consultation précoce de chirurgie plastique. Dans cinq des six cas étudies la prothèse de genou àété préservée avec une fonction satisfaisante.

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Accepted: 4 March 1998     

可旋转铰链式膝关节假体在膝关节严重畸形治疗中的应用研究

[目的]探讨可旋转铰链式膝关节假体在膝关节严重畸形治疗中的应用效果.[方法]膝关节严重畸形病例22例(24膝),男10例,女12例,平均年龄56.2岁,右侧12侧,左侧8例,双侧2例,应用可旋转铰链式膝关节假体行全膝关节置换术.采用HSS(hospital for special surgery)评分标准对手术疗效进行评价[2].[结果]手术切口一期愈合,畸形全部矫正,1例术后出现轻度深静脉血栓.随访6～55个月,功能良好,无感染及假体松动发生.[结论]采用可旋转铰链式膝关节假体置换术治疗膝关节严重畸形病例,手术操作简单,效果可靠.     

Salvaging the exposed mammary prosthesis

The authors present a new approach to handling the problem of extrusion of mammary implants. The prothesis is removed and reintroduced in the same operation. Five cases are discussed.Jaime Planas is Director and Arturo Carbonell and Jordi Planas are Assistant Surgeons at Clinica Planas.     

Total knee replacement with the Kodama-Yamamoto knee prosthesis

Since 1970, 170 knees have been operated upon using the Kodama-Yamamoto knee prosthesis. Of these 127 had the revised Mark-II prosthesis and of this group 91 cases have been followed for more than a year. Interim results suggest that the total knee score has improved. on the average, from 38 points preoperatively to 74 points after one year. A single early complication involved loosening of the prosthesis in a case of knee infection. Except for this case, no loosening and no radiolucent lines have been observed. Methacrylate bone cement is known to be harmful to bone and soft tissues, and our basic and clinical studies reveal that results improve when the total knee replacement is done without using cement.     

膝关节肿瘤假体置换术后的处理及功能康复

目的:探讨膝关节肿瘤假体置换术后的处理措施和患肢功能康复方法.方法:对45例膝关节周围骨肿瘤行瘤段骨切除、定制人工膝关节置换术,术后予以规范的一般处理及药物治疗和患肢康复锻炼.结果:45例患者随访1～8年,膝关节活动度0～120°,平均功能恢复率达75%.结论:瘤段切除定制人工膝关节置换术是应用较多的保肢手术,通过规范的术后处理和功能康复锻炼,可以减少并发症的发生,使患肢更快、更好的恢复功能.     

Treatment of necrosis of the femur condyle with a medial gliding knee prosthesis

Spontaneous osteonecrosis of the femoral condyles occurs rather seldom particularly in elderly patients. Whereas some authors recommend valgusosteotomy and bone drilling, implantation of a unilateral knee prosthesis should be performed in the presence of large defects. It is reported a series of 11 patients suffering from osteonecrosis of the femoral condyle. All patients were treated by a unilateral knee prosthesis with good results except one case. The filling of the defect with cancellous bone prior to the implantation of the condylar part of the prosthesis is mandatory.     

The exposed total knee replacement prosthesis: a new classification and treatment algorithm.

The increased frequency of total knee replacement arthroplasty (TKRA) has been reflected in the number of patients with exposed prostheses referred to this unit. An algorithm has been developed to assist in the preoperative assessment of the wound and this has been tested on 25 patients with wound breakdown following TKRA. The grade of exposure so derived predicts the most appropriate surgical management. The algorithm, grading system and proposed management are described.     

The infected knee prosthesis

Deep infections are among the most severe complications in total knee arthroplasty; infection rates described in recent articles range between 1 and 2%. The most important infection risk prevention measures are skin preparation, antibiotic prophylaxis, and screening and management for methicillin-resistant Staphylococcus aureus (MRSA). Debridement and prosthesis preservation is indicated for acute postoperative infections or for acute hematogenous disseminations over well performing prostheses. The following criteria should be met for the result to be favorable: short delay from onset of symptoms (less than 2–3 weeks), Gram-positive germs, absence of prolonged wound drainage and presence of a stable implant. Two-stage replacement is currently the gold standard for treating chronic prosthetic knee infections. The survival rate free of implant removal for reinfection with this technique stands at 93% at 5 years and 85% at 10 years. Moreover, initial recovery figures are preserved with the passage of time. Survivorship free of implant removal for any reason is 90% at 5 years and 77% at 10 years. Articulated spacers seem to be better than static ones. Polymicrobial and Gram-negative infections can be controlled in late knee arthroplasty infections. On the other hand, infections by MRSA are less likely to be controlled by the standard regimens. Preoperative prophylactic antibiotics do not affect the results of intraoperative cultures and therefore they should not be withheld before surgery for an infected TKA when an organism has been identified on aspiration preoperatively, and there has been no recent (4 weeks) antimicrobial therapy.     

Problems of infected knee prosthesis

Our report is based on 47 infected knee arthroplasties that were revised and followed up in our hospital between 1984 and 1990. Various surgical and therapeutic management options are assessed. In our patient population our experience revealed that the two-stage reimplantation seemed to offer the best chances for management of infected knee arthroplasty. Infections with gram-negative bacteria tend to take a less favorable course than those caused be gram-positive organisms. A division into categories of infected knee joints is presented and the complexity of problems related to the diagnosis is discussed.