Acetabular roof reinforcement rings.

A series of 30 total hip arthroplasties was performed in 29 patients with the use of the Mueller roof reinforcement ring (RRR). The mean follow-up observation time was 30 months (standard deviation [SD] = 7.6). The clinical and radiologic results were evaluated according to the Mayo Clinic scoring system. The overall preoperative clinical score of 21.963 (SD = 18.776) points improved to a follow-up examination score of 69.533 (SD = 11.599), a correction of 68.41%. The authors' goal in this series was to implant the ring together with the polyethylene socket as close to the anatomic position of the acetabulum as possible. There was no loosening of the RRR or the polyethylene sockets, nor was there material failure in the last evaluation of the hips. No statistically significant difference was found when the differences between the follow-up scores of the primary versus the revisionary procedures were compared. The roof replacement ring has been helpful for primary and revision arthroplasties of acetabular deficiencies occurring within five years after operation.     

防内突加强杯用于髋臼侧骨缺损翻修的临床研究

 目的 探讨影响防内突加强杯髋臼翻修假体生存时间的危险因素。方法 对2002年1月至2010年6月使用防内突加强杯进行髋臼翻修的患者进行回顾性分析。有效随访病例40例40髋,男16例、女24例;手术时年龄22～77岁,平均60.3岁;随访时间12～82个月,平均39.2个月。骨缺损AAOS分型C型29例,D型11例;Paprosky分型ⅢA型29例,ⅢB型11例。采用多因素回归分析评估性别、年龄、骨缺损分类、髋臼旋转中心上移和外移尺度、臼杯外展角、臼杯固定方式(单纯经翼固定和经翼联合经髋臼螺钉固定)、植骨方式及臼杯类型与加强杯失败(松动及再翻修)的相关性。结果 末次随访时Harris髋关节评分平均(74.5±15.4)分。2例因松动而翻修,2例出现明显的放射学松动伴疼痛症状。髋臼旋转中心上移、臼杯外展角及臼杯固定方式与加强杯失败相关。当加强杯上移8.5 mm或外展角大于53.5°时,加强杯失败风险加大;使用经翼联合经髋臼螺钉固定者加强杯失败风险降低。结论 防内突加强杯可用于髋关节置换术后髋臼侧严重骨缺损的翻修,但术后中短期仍存在较高的臼杯失败风险。重建时应尽量靠近真臼水平,适当减小臼杯外展角,使用经翼联合经髋臼螺钉固定。     

Long-term results of anti-protrusion cage and massive allografts for the management of periprosthetic acetabular bone loss

From 1992 to 1995, 71 total hip arthroplasties with extensive acetabular bone loss underwent revision using bulk allografts and Burch-Schneider anti-protrusio cages. Twelve patients died of unrelated causes and 3 were lost to follow-up. Fifty-six hips were available for clinical and radiographic follow-up examination at an average of 11.7 years after surgery. The average final Harris hip score was 75. X-ray signs of incorporation of massive bone graft were observed in 49 hips. Two cases developed deep infection that required resection arthroplasty. Aseptic loosening of the acetabular cage occurred in 5 patients, and 2 of them underwent re-revision. With a total survival rate of 87.5%, anti-protrusio cages and structural allografts compare favorably with other techniques in the long-term reconstructive treatment of extensive loss of acetabular bone stock.     

The role of the macrophage in periprosthetic bone loss.

Aseptic loosening after total joint replacement remains the most common reason for long-term implant failure. Macrophages activated by submicron wear particles of the polyethylene liner used in joint replacement have been shown to be the source of periprosthetic bone loss. Understanding the role of material chemistry in macrophage activation and the subsequent effects that macrophage-derived enzymes play in the degradation of implanted biomaterials is key to developing methods for prolonging the lifespan of implantable materials.     

同种异体皮质骨板移植治疗股骨假体周围骨折

目的 评价同种异体皮质骨板移植治疗髋关节股骨假体周围骨折的临床治疗效果。方法 对7例髋关节置换术后股骨假体周围骨折患者应用深低温冷冻和环氧乙烷处理同种异体皮质骨板移植治疗股骨骨折。根据Harris评分,外周血T淋巴细胞亚群、抗体和免疫复合物检测、X线摄片以及核素骨显像评价其治疗效果。结果 患者未发生免疫排斥反应和感染,术后3、6、12、24个月Harris评分分别比术前平均增加21、32、40、40分。术后3个月骨折愈合,一部分移植骨板与宿主骨骨性连接,同位素骨显像骨板移植区放射性分布比对侧浓集。术后12个月,85％移植骨板与宿主骨融为一体,宿主股骨皮质厚度增加3～5mm,平均4．3mm,骨板放射性浓集进一步加深,15％移植骨板出现吸收现象。术后24个月,80％移植骨板重新塑形后恢复宿主股骨皮质骨密度,10％骨板表面吸收停止,股骨假体无松动。结论 深低温冷冻和环氧乙烷处理同种异体皮质骨板移植无菌、抗原性弱、生物相容性好,移植骨板能够维持骨折和假体稳定性,增加股骨局部骨量储备,避免再次手术取出金属内置物,是用来治疗股骨假体周围骨折较理想的方法之一。     

Acetabular bone loss: Accommodating a growing void

The burden of revision total hip arthroplasty continues to rise exponentially, which is a reflection of the increasing number of primary total hip arthroplasty (THA) procedures being performed, lower surgeon thresholds for THA due to excellent mid- to long-term success rates and improved survival of the general population. Acetabular bone loss encountered at the time of revision surgery can present a significant pre- and intra-operative surgical challenge. This review covers the causes, a classification system and surgical options for treatment of acetabular bone loss at revision surgery.     

Dose-dependent prevention of early periprosthetic bone loss by alendronate

AIM: Periprosthetic bone loss occurs in the first six months after total hip arthroplasty (THA) and is felt to be largely the result of initial operative irritation, immobilization, and stress shielding. This study (a prospective, randomized, open, blinded endpoint evaluation) aims at preventing bone loss around the stem with an oral bisphosphonate. METHOD: 66 healthy subjects with uncemented THA and low lumbar bone mass density (BMD) (negative T score) were treated post-operatively with alendronate as follows: n = 21 with 10 mg/d for 10 weeks (A), n = 21 20 mg/d for 5 weeks (B), n = 24 no treatment for controls (C). The periprosthetic BMD in the Gruen zones (ROI) was measured after the 2nd, 4th, 6th, and 12th month by DEXA as a percentage of the value measured one week after surgery. RESULTS: In C, there was significant bone loss in all ROI during the first months and a deficit of 29 % in ROI 7 following one year. In B, bone loss was completely prevented up to the second month, in ROI 7, a significant difference in comparison to C was registered for the entire year. In A, significant bone loss reduction during 12 months was seen. CONCLUSION: Alendronate, therefore, is capable of preventing initial periprosthetic bone loss. A dosage of 20 mg/d is required initially with daily treatment lasting at least 10 weeks.     

Alendronate inhibits periprosthetic bone loss around uncemented femoral components

Periprosthetic bone loss can be severe around the femoral component after uncemented arthroplasty. This study investigated the inhibitory effect of alendronate on periprosthetic bone loss. Seventeen patients underwent arthroplasty with an uncemented femoral component. Among them, 8 patients were given alendronate 5 mg once daily for 1 year (ALN group) and 9 patients received no pharmacotherapy (control group). Bone mineral density was measured in six periprosthetic zones by dual-energy X-ray absorptiometry at 1, 6, and 12 months after surgery. The average periprosthetic bone mineral density was 0.674–0.920 g/cm² at 1 month after surgery. From 6 months onward, the absolute bone mineral density and the ratio relative to the 1-month value were significantly decreased in the proximal zones of the femur in the control group (the ratio decreased from 0.817 to 0.769; P = 0.0040–0.0353). In the ALN group, however, the absolute and relative bone mineral density of the proximal femur remained unchanged for 12 months. In the other femoral zones, the absolute and relative bone mineral density remained unchanged throughout the study in both groups. We concluded that alendronate significantly inhibited the decrease of periprosthetic bone mineral density in the proximal femur after uncemented arthroplasty.     

骨水泥型Ⅰ期全髋关节置换术后假体周围骨质丢失的早期研究

[目的]研究人工全髋关节置换术(THR)后假体周围的骨质丢失及假体松动的防治方法。[结果]89例骨水泥型Ⅰ期全髋关节置换的患者,分成2组,观察组47例,术后每日服用阿仑膦酸钠10 mg+钙剂600 mg;对照组42例,术后每天服用600 mg钙剂。随访12个月,测定假体周围骨矿密度及骨代谢生化指标。[结果]假体周围相同区域BMD降低不明显或升高。在股骨近端(prRO I),对照组的BMD平均降低(21.2±5.2)%,而观察组平均升高(4.2±2.6)%(P<0.05)。在随访期末两组间全假体周围(totRO I)平均BMD对照组下降了(12.1±6.2)%,而观察组升高了(2.6±1.4)%,差别有统计学意义(P<0.05)。观察组BGP明显升高(P<0.05),而对照组ACP升高(P<0.05)。[结论]阿伦膦酸钠可明显降低骨水泥型Ⅰ期全髋置换术后骨质丢失,改善骨骼对假体的支撑作用,可能会预防或延缓假体松动。     

Acetabular reinforcement in total hip replacement

Summary In 21 cases of severe secondary protrusio acetabuli with extensive or total destruction of the acetabular cortical structures, the double anchorage of conventional polyethylene cups with nine Müller acetabular reinforcement rings and 12 Burch-Schneider anti-protrusio reinforcement cages was carried out. They were applied in combination with reconstructive surgery of cancellous bone in three primary total hip replacements and in 18 revision operations for lossened acetabular cups following total arthroplasties. Indication for and technique of the acetabular reinforcement are described. The radiological and clinical results in 21 patients followed up were satisfactory. They confirm the efficiency of these screw-fixed reinforcement implants for the solid fixation of the plastic cup in patients with extreme acetabular deficiencies.

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Zusammenfassung Bei 21 Patienten mit ausgeprägter sekundärer Protrusio acetabuli und weitgehender oder völliger Zerstörung der kortikalen Pfannenstrukturen wurde die Doppelverankerung der zementfixierten Ersatzpfannen mit 9 Müller Pfannendachschalen und 12 Burch-Schneider Pfannenstützschalen durchgeführt. Sie wurden in Kombination mit einer rekonstruktiven Spongiosaplastik bei 3 Erstimplantationen von Totalendoprothesen und bei 18 Revisionseingriffen zur Auswechslung von ausgelockerten Pfannenimplantaten eingesetzt. Indikation und Technik der Pfannenarmierung werden beschrieben. Die radiologischen und klinischen Resultate der 21 nachuntersuchten Patienten waren zufriedenstellend. Sie bestätigen die Leistungsfähigkeit dieser schraubenfixierten Armierungsimplantate, die eine stabile Pfannenfixation bei hochgradigen zentralen Azetabulumdefekten gewährleisten.

     

Acetabular reinforcement in total hip replacement

In 21 cases of severe secondary protrusio acetabuli with extensive or total destruction of the acetabular cortical structures, the double anchorage of conventional polyethylene cups with nine Müller acetabular reinforcement rings and 12 Burch-Schneider anti-protrusio reinforcement cages was carried out. They were applied in combination with reconstructive surgery of cancellous bone in three primary total hip replacements and in 18 revision operations for loosened acetabular cups following total arthroplasties. Indication for and technique of the acetabular reinforcement are described. The radiological and clinical results in 21 patients followed up were satisfactory. They confirm the efficiency of these screw-fixed reinforcement implants for the solid fixation of the plastic cup in patients with extreme acetabular deficiencies.     

Moderate heat treatment of bone allografts

Summary The use of bone allografts is often essential in orthopedic surgery. Strict donor screening, including HIV testing 3 months postoperatively, is mandatory before a transplant may be used. Yet these measures do not definitely rule out the possibility of HIV transmission, as there is a window period before infection is revealed by blood testing. Accordingly, there is a need for virus inactivation methods that can be used on bone allografts. As radiation treatment and chemical methods have a number of disadvantages, we chose a moderate heat treatment of 65°C for a series of animal experiments. In 12 rabbit femoral condyles, moderate-heattreated bone allografts were implanted into 6-mm drill holes. Twelve normal allografts and 12 empty drill holes served as controls. Radiologic and histological evaluation up to 12 weeks postoperatively revealed slow spontaneous bone remodeling from the rim to the center of the empty cavities. Normal deep frozen allografts were quickly integrated after a short period of osteoclast reaction around the transplant, with occasional bone bridges between host and allgraft. The examination of heattreated allografts showed no differences to the controls, including morphologic aspects and the time course of osteointegration. Five zones of bone repair and osteointegration were distinguished. We conclude that thermal treatment of bone allografts has no adverse effects on osteointegration in the rabbit femoral condyle. Thus, it may contribute to improving safety in human bone transplantation.     

Acetabular reinforcement in total hip replacement

Summary In conclusion, based on our experimental and clinical material and analysis of failures, we recommend wire mesh reinforcement and bone graft for patients with mild to moderate protrusio. If the floor is strong but the pillars deficient, then the Eichler ring alone is the best implant. The combined system of wire mesh and Eichler ring should be used in cases of protrusio with a large deficiency of the acetabular floor and for protrusio with pillar weakness. Furthermore a bone graft should be used to reinforce the acetabular floor in addition to any prosthetic device.Dedicated Prof. Dr. E. Uehlinger on his 80th birthday     

Massive intercalary bone allografts in the treatment of primary and secondary bone tumors

From 1981 to 1993, 21 patients received intercalary bone allografts for reconstruction of the extremity after en bloc tumor resection (15 malignant and 6 benign tumors). The allografts were collected from multiorgan donors and cryopreserved at –70°C. The mean follow-up was 4.4 (range 1–13) years. The fate of the grafts was followed by conventional radiography, bone scintigraphy, and functional assessment. The overall survival rate of the 7 patients with high-grade malignancies was 86%. Solid union of the graft-host sites in less that 15 months occurred in 85%. An increased isotope uptake of the graft indicates that incorporation at the osteotomies as well as remodelling is still continuing at 9 years after operation. The overall complication rate was 43%; 3 patients had two or more complications. Complications were related to the allograft in 6 (infection or fatigue fracture in 1 and delayed healing in 4 cases) and to the osteosynthesis in 3 patients. The definitive results after treatment of complications show that satisfactory results have been obtained in all but 2 patients: 62% had excellent, 19% good, and 10% fair results. Intercalary allografts therefore provide a valuable solution for large skeletal defects after resection of bone tumors.     

Acetabular revision surgery with impacted bone allografts and cemented cups in patients younger than 55 years

This article summarises a clinical and radiographical analysis of 30 acetabular revisions in patients younger than 55 years old, performed with impaction bone grafting and cemented cups. Preoperative Merle D’Aubigne and Postel functional score was an average 7 points. At a mean follow-up of 86.5 months (range 34–228) functional score averaged 16.3 points. Radiolucent lines with no clinical impact were observed in 7% of DeLee and Charnley acetabular zones evaluated. Massive radiological migration, consistent with clinical failure, was observed in two cups. Three patients underwent re-revision surgery (10%): two due to infection and one due to mechanical failure. Reconstruction survival rate was 89% (CI 95% 71.9–96.4) overall, and 96% (CI 95% 82.6–99.3) ruling out cases of infection. Impacted bone allograft constitutes one of the reconstructive techniques of choice in acetabular revision surgery of young patients. Restoration of bone stock is essential in this group of patients due to the possibility of future revisions.

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Résumé  Nous avons analysé cliniquement et radiographiquement 30 révisions acétabulaires chez des patients jeunes agés de moins de 55 ans, révision réalisée avec une greffe impactée et une cup cimentée. Le score pré-opératoire de Postel Merle d’Aubigné était en moyenne à 7 points. Après un suivi moyen de 86,5 mois (de 34 à 228 mois) le score post-opératoire de Postel Merle d’Aubigné était en moyenne à 16,3 points. Des liserés sans traduction clinique ont été observés dans 7% des cas et analysés selon DeLee et Charnley. Une migration massive radiographique avec un échec clinique a été observé dans deux cas. 3 patients ont nécessité une nouvelle révision (10%), 2 pour infection et 1 pour échec clinique. Le taux de survie de cette reconstruction a été de 89% (intervalle de confiance 95% 71.9–96.4) et de 96% (intervalle de confiance 95% 82.6–99.3) pour les cas d’infection. L’allogreffe impactée constitue une technique de choix pour la reconstruction lors d’une révision acétabulaire chez des patients jeunes. La restauration du stock osseux est essentielle dans ce groupe de patients et permet d’anticiper de futures révisions.

     

髋臼加强环联合同种异体骨植骨髋关节翻修的中期临床疗效观察

[目的]观察分析髋臼加强环联合同种异体骨植骨在严重髋臼骨缺损人工髋关节翻修术中的应用及临床疗效,探讨其在髋臼骨缺损重建中的作用。[方法]2010年3月~2015年2月,采用髋臼加强环联合同种异体骨植骨行髋关节翻修75例(87髋),67例患者79髋获得随访(失随访8例)。男39例,女28例;年龄45~72岁,平均59.2岁。初次置换至此次翻修时间为2~15年,平均10.3年。翻修原因:假体松动和骨溶解。术前髋关节功能Harris评分为(32.5±3.3)分。髋臼骨缺损按照美国骨科医师协会(AAOS)分型标准:Ⅲ型51髋,Ⅳ型28髋。[结果]67例患者79髋获得随访(失随访8例),随访时间3~60个月,平均32个月。术后切口Ⅰ期愈合,无股神经和坐骨神经损伤、下肢深静脉血栓形成等并发症发生。3例患者术后1个月发生髋关节脱位,2例腰麻下切开复位,1例手法复位后无再脱位。患者术后疼痛症状均明显缓解或消失,末次随访时髋关节Harris评分为(82.5±8.2)分,与术前比较差异有统计学意义(P=0.002)。X线片提示髋臼假体均无骨溶解、松动,所植异体骨与宿主骨融合,未见明显骨吸收区。[结论]采用髋臼加强环联合同种异体骨植骨技术,髋臼假体可获得满意的初始稳定,近期疗效满意,远期疗效尚需进一步观察。髋臼加强环联合同种异体骨植骨可成为严重髋臼骨缺损人工髋关节翻修时重建髋臼的方法之一。