Uncemented femoral revision arthroplasty using the modular revision prosthesis MRP-TITAN revision stem

Objective  Restoration of a painless hip joint capable of bearing weight by uncemented implantation of a rotationally stable, modular revision stem anchored in the diaphysis. Indications  Prosthetic stem loosening with osteolytic bone defects (defect classification types I–III according to Paprosky), material failure with broken prosthesis, sub-and/or periprosthetic femoral fractures, and tumors. Contraindication  Extensive osteolysis preventing diaphyseal anchorage of the prosthetic stem. Surgical technique  Transgluteal approach to the hip joint. Removal of the loose prosthetic stem and, if cemented, the bone cement as well. Excision of intramedullary granulation tissue. Reaming of the medullary cavity with flexible reaming shafts and formfit, uncemented implantation of the star-shaped modular revision stem with diaphyseal press-fit. If there is extensive loss of metaphyseal bone stock, augmentation with autogenous-allogenic bone should be performed. Postoperative management  Mobilization on two underarm crutches from the 1st postoperative day. Removal of the Redon drains after 48 hours. Partial loading with 20 kg for 6 weeks postoperatively. If plain radiographs show unchanged seating of the prosthesis after 6 weeks, loading can be increased by 10 kg per week until full weight bearing is achieved; thrombosis prophylaxis is continued throughout. Radiologic checkups will be done after 3, 6, and 12 months. After that, the patient should be checked annually. Results  Forty-five patients (N = 48 prostheses) with an average age of 67.2 years (min/max: 42.4–87.4 years) were investigated. The average implantation time of the Modular revision prosthesis MRP-TITAN revision stem was 4.7 years (min/max: 1.0–9.0 years). The Harris hip score for Paprosky bone defect types I–III had increased from 25.6 preoperatively to 71.4 postoperatively at the time of the final follow-up (p ³ 0.05). Extensively defective bone was diagnosed preoperatively in 32 patients (¹Paprosky IIB). Plain radiographs showed stable anchorage without migration in 44 patients. In one case, the stem (implantation time 2.36 years) was replaced due to increasing axial subsidence (¹5 mm). Good integration of bone graft with subsequent defect regeneration was seen in all patients with bone trans-plant (N = 30). Postoperative dislocation occurred in six patients and required closed reduction in four cases. Open reduction was performed in two patients, whereby the external rotation angle of the prosthetic neck was corrected without dismantling the distally anchored prosthetic stem components. The mechanical failure rate over the follow-up period of 9 years was 1 out of the 48 prospectively investigated prostheses. The rate of survival according to Kaplan-Meier was 97%.     

The cement-free modular revision prosthesis MRP-hip revision stem prosthesis in clinical follow-up

INTRODUCTION: We present prospective medium-term results of the modular revision prostheses "MRP-TITANIUM". MATERIAL AND METHODS: 45 patients (n = 48 prostheses) were evaluated. The mean follow-up was 4.7 years (min.-max.: 1.0-9.0 years). Pre- and postoperatively the Harris hip score (differentiated to Paprosky I-III) was examined. 66.67 % of the cases had extensive bony defects (> or = Paprosky II b). By means of X-ray examinations, the stability of the prostheses, periprosthetic bone remodelling, the presence of radiolucent lines as well as bone defect regeneration were assessed postoperatively. RESULTS: The mean Harris hip score improved from 25.6 preoperative to 71.4 postoperative (p < or = 0.05). In 44 cases the X-ray showed stable fixation without secondary migration. In one case the stem (stand time 2.36 years) was revised due to secondary migration (> or = 5 mm). The survival rate (Kaplan-Meier) was 97 %. Bone transplantation with consecutive defect regeneration was (n = 30) complete in all cases. In six cases (12.5 %) a postoperative dislocation occurred with subsequent successful closed reposition four times (8.3 %). In two cases (4.2 %) an open reposition was done with correction of the antetorsion angle of the prostheses. CONCLUSION: The "MRP-TITANIUM modular revision prostheses" has proved to be reliable in cases of revision surgery with extensive bony defects. The failure rate was 2.1 % for 48 prospectively examined prostheses.     

Uncemented femoral revision arthroplasty using a modular tapered,fluted titanium stem

Background and purpose — Due to the relative lack of reports on the medium- to long-term clinical and radiographic results of modular femoral cementless revision, we conducted this study to evaluate the medium- to long-term results of uncemented femoral stem revisions using the modular MRP-TITAN stem with distal diaphyseal fixation in a consecutive patient series.

Patients and methods — We retrospectively analyzed 163 femoral stem revisions performed between 1993 and 2001 with a mean follow-up of 10 (5–16) years. Clinical assessment included the Harris hip score (HHS) with reference to comorbidities and femoral defect sizes classified by Charnley and Paprosky. Intraoperative and postoperative complications were analyzed and the failure rate of the MRP stem for any reason was examined.

Results — Mean HHS improved up to the last follow-up (37 (SD 24) vs. 79 (SD 19); p < 0.001). 99 cases (61%) had extensive bone defects (Paprosky IIB–III). Radiographic evaluation showed stable stem anchorage in 151 cases (93%) at the last follow-up. 10 implants (6%) failed for various reasons. Neither a breakage of a stem nor loosening of the morse taper junction was recorded. Kaplan-Meier survival analysis revealed a 10-year survival probability of 97% (95% CI: 95–100).

Interpretation — This is one of the largest medium- to long-term analyses of cementless modular revision stems with distal diaphyseal anchorage. The modular MRP-TITAN was reliable, with a Kaplan-Meier survival probability of 97% at 10 years.     

生物型组配式锥形柄行全髋关节翻修术的中远期疗效

目的探讨应用生物型组配式锥形柄行全髋关节翻修术的中、远期疗效。 方法收集苏州大学附属第一医院2000年5月至2011年5月因假体无菌性松动、股骨侧骨缺损而采用生物型组配式锥形柄行全髋关节翻修手术的患者,排除肿瘤、假体感染及随访时间<5年的患者,共收录37例(39髋),其中采用利马股骨翻修柄19例(21髋),林克(LINK)MP翻修柄18例(18髋)。初次置换至翻修时间为4～15年,平均(10±4)年,均为首次翻修。股骨侧骨缺损分型按Paprosky标准：Ⅲa型28髋,Ⅲb型11髋。摩擦界面均使用陶瓷－陶瓷界面。Harris评分比较采用t检验,骨缺损程度分型组间差异采用卡方检验。 结果全部病例随访6～16年,其中11例随访6～10年,26例随访超过10年,平均(11.6±2.3)年。两种假体翻修时股骨缺损程度未见明显差异(χ²＝0.434; P>0.05)。术前平均Harris髋关节评分为(43±10)分,末次随访为(90±3)分(t＝32.334,P<0.05),两种翻修假体的临床疗效差异无统计学意义(t＝0.881,P>0.05)。X线随访显示翻修柄骨性稳定者38髋(97.4%),纤维稳定者1髋(2.6%)。假体平均下沉(2.1±2.3) mm(0～10 mm)。随访期间无1例因假体松动或其他原因需行再次翻修。 结论采用生物型组配式锥形柄假体行伴有Paprosky Ⅲa和Ⅲb型骨缺损的股骨侧假体翻修,可获得理想的初始稳定和永久生物学固定,中、远期随访疗效满意。     

Stay Short or Go Long in Revision Total Hip Arthroplasty With Paprosky Type II Femoral Defects: A Comparative Study With the Use of an Uncemented Distal Fixating Modular Stem and a Primary Monobloc Conical Stem With 5-Year Follow-Up

BackgroundIn the revisions for Paprosky type II femoral defects, diaphyseal fixating femoral stems are commonly used. To preserve bone stock, the use of a shorter primary conical stem could be an adequate alternative. The objective of this study is to compare the results of a primary conical stem to the more commonly used diaphyseal fixating modular revision stem in revision total hip arthroplasty surgery with Paprosky type II femoral defects.MethodsA total of 59 consecutive patients with Paprosky type II femoral defects from our prospective revision registry were included. Thirty patients who received a long distal fixating modular stem (Revision Stem, Lima Corporate) and 29 patients who received a primary conical short stem (Wagner Cone, Zimmer) were prospectively followed. Minimal follow-up time was 2 years for subsidence and patient-reported outcome measures and 5 years for complications, reoperation, and revision. We compared subsidence, perioperative complications, reoperations, femoral component survival, Oxford Hip Score, EuroQol 5 Dimension, visual analog scale (VAS) for pain at rest, and VAS for pain during activity between stems.ResultsBoth groups were comparable regarding demographic, clinical, and surgery-related characteristics. We found more perioperative complications and stem revisions with the modular revision stem than with the primary conical stem. There were no statistical differences in subsidence, EuroQol 5 Dimension, Oxford Hip Score, and VAS for pain at rest or during activity between both stems.ConclusionIn revision total hip arthroplasty with Paprosky type II femoral defects, uncemented primary monobloc conical femoral stems showed the same clinical result as distal fixating modular stems with fewer complications and fewer stem revisions.     

远端固定生物型假体在股骨翻修术中的应用

目的探讨远端固定生物型假体结合干燥同种异体骨植骨在近端骨缺损股骨翻修术中的应用疗效。方法自1999年7月至2004年1月,对16例（17髋）非感染性股骨假体松动患者进行翻修手术,其中2例为再次翻修,采用远端固定生物型股骨假体结合干燥同种异体骨植骨。男7例,女9例,年龄58～77岁,平均63岁,术后平均随访时间为35个月（18～56个月）。翻修前人工股骨头置换5例,全髋关节置换12例,从初次关节置换到翻修手术的间隔时间最短7年,最长16年,平均13．5年。股骨骨缺损根据Paprosky分型,Ⅰ型8髋,Ⅱ型6髋,ⅢA型3髋。翻修用假体：MP（Link）1髋,AML（DePuy）9髋,Full—coated（Zimmer）5髋,Enchelon（Smith—Nephew）股骨距替代型假体2髋。结果Harris评分从术前平均37分改善至术后平均88分,无患者发生再次松动。术后X线片显示植入骨愈合良好,假体部位骨皮质密度和厚度明显增加。结论远端固定生物型假体可以在股骨远端髓腔内获得可靠的轴向及抗旋转初始稳定性,干燥异体骨植骨能有效修复骨缺损,恢复骨量,骨愈合率高,两者结合运用于伴有近端骨缺损的股骨翻修术中,中短期疗效满意,远期疗效尚待进一步随访。     

The endlock tumor prosthesis with short-length fixation: a clinical study

Anchorage of segmental replacement prostheses in diaphyseal bone remains a challenge in lower limb reconstructions. We developed and studied a new prosthesis design that features an intramedullary anchorage system for which finite element analysis predicted favorable bone remodeling. We retrospectively analyzed the cases of all patients who underwent implantation of the new stem. Their data were prospectively collected. Twenty-four patients (25 prosthetic reconstructions using diaphyseal fixation of the prosthesis) had 18 primary implantations and 7 revision cases. At a mean follow- up of 61 months, TESS (Toronto Extremity Salvage Score) and MSTS (Musculoskeletal Tumor Society Rating Scale score) were 80% and 65% that of a normal extremity, respectively. SF-36 (36-Item Short-Form Health Survey) Mental and Physical scores were 54 and 44 points, respectively. Minimum follow-up was 31 months (mean, 61 months; range, 31-107 months). Radiographic evaluation (1991 International Symposium of Limb Salvage [ISOLS] Radiological Implant Evaluation System) revealed 65% excellent and 35% good bone remodeling around the implant as a whole, 65% excellent and 35% good results for the anchorage proper, and 70% excellent and 30% good findings for lucencies at the bone-metal interface. Two patients (1 traumatic event) developed a loose stem. The results support the expectations as shown by finite element analysis - that the risk for loosening is reduced and that favorable bone remodeling occurs around the stem over time.     

Two-stage revision of infected uncemented lower extremity tumor endoprostheses

We reviewed our experience with 2-stage revision of uncemented Kotz Modular Femoral and Tibial Replacement System prostheses from 1989 to 2004. A total of 180 lower extremity tumor prostheses were inserted, 15 of which underwent removal of the prosthesis for infection. Eleven patients underwent subsequent second-stage revision, and 4 underwent amputation. Of the 11 patients who underwent revision, 8 continue to be free of infection an average of 33 months postoperatively. Of these 8 patients, 6 were revised without removal of the diaphyseal anchorage piece, which were all well ingrown. Most successful revisions were in the group that developed infection within 6 months of their original procedure. Two-stage revision of uncemented tumor endoprostheses with retention of a well-ingrown stem can be associated with successful eradication of infection.     

Revision of the Kotz type of tumour endoprosthesis for the lower limb

In 251 patients over a period of 15 years an uncemented Kotz modular femoral and tibial reconstruction mega prosthesis was implanted after resection of a malignant tumour of the lower limb. Twenty-one patients (8.4%) underwent revision for aseptic loosening, again using an uncemented prosthesis, and five of these required a further revision procedure. The median follow-up time from the first revision was 60 months (11 to 168) and after a second revision, 33 months (2 to 50). The probability of a patient avoiding aseptic loosening for ten years was 96% for a proximal femoral, 76% for a distal femoral and 85% for a proximal tibial implant. At the time of follow-up all radiographs were assessed according to the International Symposium of Limb Salvage criteria. The first radiological signs of aseptic loosening were always seen at the most proximal or distal part of the anchorage stem at a mean of 12 months (4 to 23) after the first implantation. Using the Musculoskeletal Tumor Society score for evaluation, the clinical results showed a mean of 88% of normal function.     

Results of uncemented distal locked prosthesis in revision hip arthroplasty with proximal femoral bone loss: A retrospective study

Introduction:

Management of bone loss is a challenge in revision total hip arthroplasty (THA). A retrospective review was performed to study the use of uncemented distal locked prosthesis in cases with proximal femoral bone loss.

Materials and Methods:

Uncemented stems with distal interlocking were used in 65 hips during revision THAs with 38 hips having Paprosky IIIB/IV defects between January 1998 and February 2004. There were 48 males and 17 females in the study with an average age of 53 years (range 30-80 years). Radiographic and clinical outcome evaluation using the Harris hip score (HHS) were performed.

Results:

An improvement in HHS (mean: 33 points) was observed at final followup (mean: 9 years). Regeneration of proximal bone stock was observed without signs of loosening or subsidence and none of the stems were revised. Three patients developed recurrent dislocation while one had a stem subsidence of 1cm following removal of interlocking bolts.

Conclusion:

Uncemented distal locked prosthesis provide adequate stability in revision THA, aiding the reconstruction of bony deficiencies while avoiding the disadvantages of fully porous or cemented implants.     

Uncemented or cemented stems in first-time revision total hip replacement? An observational study of 867 patients including assessment of femoral bone defect size

Background and purpose — Uncemented stems are gradually replacing cemented stems in hip revision surgery. We compared the risk of re-revision between uncemented and cemented revision stems and assessed whether the different fixation methods are used in similar femoral bone defects.Patients and methods — 867 patients operated on with uncemented or cemented stems in first-time hip revision surgery due to aseptic loosening performed 2006–2016 were identified in the Swedish Hip Arthroplasty Register. Preoperative femoral bone defect size was assessed on radiographs of all patients. Cox regression models were fitted to estimate the adjusted risk of re-revision during different postoperative time periods. Re-revision of any component for any reason, and stem re-revision, as well as risk of cause-specific re-revision was estimated.Results — Most patients in both fixation groups had Paprosky class IIIA femoral bone defects prior to surgery, but there were more severe bone defects in the cemented group. The adjusted risk of re-revision of any component for any reason was higher in patients with uncemented compared with those with cemented revision stems during the first 3 years after index surgery (hazard ratio [HR] 4, 95% confidence interval [CI] 2–9). From the 4th year onward, the risk of re-revision of any component for any reason was similar (HR 0.5, CI 0.2–1.4). Uncemented revision stems conferred a higher risk of dislocation compared with cemented stems (HR 5, CI 1.2–23) during the first 3 years.Interpretation — Although not predominantly used in more complex femoral defects, uncemented revision stem fixation confers a slightly higher risk of re-revision during the first years, but this risk is attenuated after longer follow-up.

The increased use of primary total hip replacement (THR) has been followed by a steady rise in the frequency of revision surgery (Kurtz et al. 2007, Rajaee et al. 2018), and the use of uncemented revision stems is increasing in most countries (Swedish Hip Arthroplasty Register [SHAR] 2015). Some surgeons consider uncemented revision stems to be more appropriate in situations with extensive femoral bone loss, but others use long cemented revision stems, sometimes in conjunction with bone impaction grafting. Ultimately, the choice of fixation method in revision surgery is a matter not only of science and evidence, but also of taste and local tradition.Register-based studies indicate that uncemented revision stems may have inferior implant survival when compared with cemented stems, especially in the older population (Weiss et al. 2011, Tyson et al. 2019). However, these register studies lack information on femoral bone defect size, a factor that can affect the choice both of fixation method and of outcome in terms of re-revision rates (Paprosky et al. 1999, Pekkarinen et al. 2000, Della Valle and Paprosky 2004, Ten Have et al. 2012).Some smaller observational studies address bone defect size: in 86 patients with comparable femoral bone defects the choice of fixation has no certain influence on implant survival (Iorio et al. 2008), whereas uncemented revision stems conferred inferior implant survival compared with cemented revision stems in 209 patients with comparable femoral bone defects (Hernigou et al. 2015). However, both studies included different reasons for revision surgery, and the second study included both first-time and multiply revised patients.Taken together, the available evidence on the optimal mode of revision stem fixation is hampered by small cohort sizes and lack of control groups (Berry et al. 1995, Iorio et al. 2008, Ornstein et al. 2009, Lakstein et al. 2010, Hernigou et al. 2015, Stigbrand and Ullmark 2017), there is a lack of information on indications underlying revision surgery (Iorio et al. 2008, Weiss et al. 2011, Hernigou et al. 2015), and, most importantly, in large register studies there is no information on the femoral bone defect sizes present at revision surgery (Weiss et al. 2011, Tyson et al. 2019). Our primary aim was therefore to compare the risk of re-revision of any component for any reason between uncemented and cemented stems in hip revision surgery with adjustment for preoperative femoral bone defect size in a large cohort of patients. Our secondary aims were to investigate whether uncemented and cemented revision stems were used in patients with different bone defect sizes, and to assess if the risk of stem re-revision, as well as risk of re-revision of any component due to aseptic loosening, dislocation, fracture, deep infection, and other reasons differed between the 2 fixation techniques.     

Modifizierter transfemoraler Zugang zum Wechsel von Hüftendoprothesen mit modularen zementlos implantierbaren Revisionsschäften

OBJECTIVE: Removal of a loose or fractured stem in total hip arthroplasty. Implantation and secure fixation of a modular uncemented revision stem to restore painless joint function. INDICATIONS: Loose and/or broken prosthetic stem. Risk of intraoperative fracture or perforation of the femur when stem revision becomes unavoidable. Periprosthetic fracture. CONTRAINDICATIONS: Loose prosthetic stems that can be revised without the risk of perforation or fracture of the femur. Interprosthetic femoral fractures between the ends of hip and knee prosthetic stems that require total replacement of the femur. SURGICAL TECHNIQUE: Exposure of the femur anterior to the lateral lip of the linea aspera in the lateral intermuscular septum. 3.2-mm drill holes are made at the anterior and posterior ends of the planned bone flap. Osteotomy of the femur anterior to the junction of the vastus lateralis and the gluteus medius muscles. Posterior osteotomy as well as distal transverse osteotomy between the drill holes and distal anterior osteotomy. The anterior osteotomy is performed using a chisel passed under the vastus lateralis from distal to proximal at the anterior aspect. The osteotomized lateral femoral bone flap with muscle attachment is folded back. Implantation of a modular uncemented revision stem and fixation of the bone flap with double cerclage. POSTOPERATIVE MANAGEMENT: Thrombosis prophylaxis, physiotherapy, gait training with partial loading of the limb at 10 kg for a period of 6 weeks with hip flexion limited to 70 degrees. Then, free range of movement and increased loading by 10 kg per week. RESULTS: 74 modular uncemented revision stems were implanted in transfemoral technique and the outcomes clinically and radiologically analyzed over an average follow-up period of 20.2 +/- 12.1 months (10-43 months). The Harris Hip Score increased from a preoperative value of 42.21 to 85.97 points after 2 years. Subsidence was observed for four stems and early loosening for two stems. The press-fit anchorage of these latter two stems was < 3 cm.     

Uncemented femoral revision arthroplasty using a modular tapered,fluted titanium stem: 5- to 16-year results of 163 cases

Background and purpose —

Due to the relative lack of reports on the medium- to long-term clinical and radiographic results of modular femoral cementless revision, we conducted this study to evaluate the medium- to long-term results of uncemented femoral stem revisions using the modular MRP-TITAN stem with distal diaphyseal fixation in a consecutive patient series.

Patients and methods —

We retrospectively analyzed 163 femoral stem revisions performed between 1993 and 2001 with a mean follow-up of 10 (5–16) years. Clinical assessment included the Harris hip score (HHS) with reference to comorbidities and femoral defect sizes classified by Charnley and Paprosky. Intraoperative and postoperative complications were analyzed and the failure rate of the MRP stem for any reason was examined.

Results —

Mean HHS improved up to the last follow-up (37 (SD 24) vs. 79 (SD 19); p < 0.001). 99 cases (61%) had extensive bone defects (Paprosky IIB–III). Radiographic evaluation showed stable stem anchorage in 151 cases (93%) at the last follow-up. 10 implants (6%) failed for various reasons. Neither a breakage of a stem nor loosening of the morse taper junction was recorded. Kaplan-Meier survival analysis revealed a 10-year survival probability of 97% (95% CI: 95–100).

Interpretation —

This is one of the largest medium- to long-term analyses of cementless modular revision stems with distal diaphyseal anchorage. The modular MRP-TITAN was reliable, with a Kaplan-Meier survival probability of 97% at 10 years.Long-term outcome of femoral revision arthroplasty depends on proper restoration of joint mechanics by reconstructing the anatomic center of rotation in combination with fixation that provides long-term stability (Gravius et al. 2011).The published medium- to long-term survival rates of cemented revision THA are between 35% and 91% (Kavanagh and Fitzgerald 1985, Retpen et al. 1989, Stromberg and Herberts 1996, Weber et al. 1996). One stage cemented stem revision leads to increased bone loss (Rader and Eulert 2005) and is associated with a much higher rate of re-revision than cementless femoral stem revision (Dohmae et al. 1988). Cemented revision stems only appear to be advisable for less active patients with an average life expectancy of less than 10 years (Weiss et al. 2011). In comparison, uncemented revision hip arthroplasty gives medium- to long-term survival rates of 60–97% (Head et al. 2001, Engh et al. 2002, Kwong et al. 2003).Over the years, uncemented modular revision stems have become increasingly popular (Fink et al. 2009). In complex revision surgery, modular uncemented femoral implants may overcome the limitations of non-modular and mostly straight stems—for example, the difficulty in establishing femoral leg length, femoral anteversion, and soft tissue tension (Berry 2002, Mumme et al. 2004, Gutierrez et al. 2007). Modular cementless implant systems with a distal diaphyseal press-fit concept provide greater variability in difficult anatomical situations than non-modular revision stems (Berry 2002). The modular-designed components offer the opportunity to customize the prosthesis intraoperatively to the individual anatomical situation, allowing nearly physiological joint reconstruction (Gravius et al. 2011).Based on published studies, the modular cementless MRP-TITAN revision stem with its distal diaphyseal fixation concept has well-proven short-term effectiveness in femoral revision, especially for large femoral defects (types IIC and III, as described by Paprosky et al. (1990)). Previous studies have shown low mechanical failure rates of 2–5% after 4–5 years of follow-up (Wirtz et al. 2000, Mumme et al. 2004, 2007).Due to the relative lack of medium- to long-term results of femoral modular cementless revision surgery in the literature, we investigated the clinical and radiographic medium- to long-term outcome of femoral revision arthroplasty with the MRP-TITAN stem in a consecutive patient series.     

全髋关节翻修术中髋臼骨缺损的处理方法

目的探讨全髋关节翻修术中对于髋臼骨缺损重建的方法及其术后疗效。方法回顾性分析自2007-03—2011-12的75例（76髋）全髋关节翻修术,髋臼骨缺损根据Paprosky分型：Ⅰ型9髋,ⅡA型21髋,ⅡB型18髋,ⅡC型11髋,ⅢA型10髋,ⅢB型7髋。髋臼骨缺损采用不同方式修复,术后定期随访。采用髋关节功能Harris评分评估髋关节功能,根据X线片判断假体是否松动、植骨是否融合。结果 75例（76髋）均获得平均36（16~73）个月随访。术后12个月不同类型骨缺损患者髋关节功能Harris评分较术前明显提高,差异有统计学意义（P〈0.05）。术后症状和关节功能明显改善,未出现髋臼骨折、感染、下肢深静脉血栓形成、坐骨神经损伤等严重并发症。X线片可见移植骨与宿主骨质交界处有连续性骨小梁通过,假体未见松动迹象。结论髋臼假体无菌性松动及骨溶解是需要进行全髋关节翻修的主要原因,而髋臼骨缺损Paprosky分型法对髋臼翻修重建方法有指导意义,正确选择假体类型及合理选择植骨方式是全髋关节翻修术后取得满意疗效的保证。     

Treatment of Vancouver B3 periprosthetic femur fractures with a fluted tapered stem

Periprosthetic femur fractures around a hip arthroplasty associated with a loose stem and severely deficient or comminuted bone typically have been treated with substitution for the proximal femur using an allograft prosthetic composite or a tumor prosthesis. Eight patients (mean age, 68 years; range, 34-80 years) with Vancouver Type B3 femur fractures were treated with revision using a long modular fluted tapered uncemented stem with retention of the proximal femur. Access to the failed prosthesis and joint was gained through the fracture or osteotomy and soft tissue attachments to the fracture fragments were maintained. One patient died within 1 week. The remaining patients were followed up 1 to 2 years (mean, 1.5 years). At final followup, all patients had stable implants and all acute fractures were healed. Marked reconstitution of proximal femoral bone stock was observed consistently. All surviving patients were ambulatory and none had more than mild pain. The preliminary results of this method show a high rate of stable implant fixation and fracture healing with preservation and reconstitution of the host femur.     

人工髋关节置换术后感染二期关节再置换的假体选择

目的 探讨人工髋关节置换术后感染二期关节再置换的假体选择.方法 1999年1月至2007年12月,共32例单侧人工髋关节置换术后感染二期关节再置换的患者,男19例,女13例,平均56岁(32～80岁).髋臼侧Paprosky骨缺损分型:Ⅰ型13例,ⅡA型9例,ⅡC型5例,ⅢA型1例,ⅢB型4例;对Ⅰ～ⅡA型髋臼骨缺损(22例),应用非骨水泥型假体;对ⅡC～ⅢB型髋臼骨缺损(10例),给予植骨、加强环和髋臼网等方法进行充分重建,应用骨水泥型假体.股骨侧Paprosky骨缺损分型:Ⅰ型11例,Ⅱ A型4例,ⅡB型1例,ⅡC型5例,ⅢA型6例,ⅢB型3例,ⅢC型2例;选用骨水泥型假体8例(ⅡC型5例,ⅢB型3例),近端固定生物型假体5例(Ⅰ型),广泛涂层型假体11例(Ⅰ型6例,ⅡA型4例,ⅡB型1例),远端同定型假体8例(ⅢA型6例,ⅢC型2例).结果 术后随访1～10年,平均5年2个月.术后2例患者反复发生感染,因患者拒绝再次取出假体,仅行清创和保守治疗;末次随访时仍存在窦道;Harris评分分别为65和78分.其余30例患者效果满意,Harris评分由二期手术前的平均48分(31～78分)提高到术后平均85分(80～95分).末次随访时X线片与术后当时的X线片对比,30例患者的假体均无下沉、移位和松动.结论 人工髋关节置换术后感染二期关节再置换手术的成功率高,手术重点是确认感染已获得良好控制后,针对骨缺损类型选择相应的假体.     

Long-term analysis of cement-free implanted PCA knee endoprostheses with 5-8 year follow-up]

A total of 54 PCA knee-joint endoprostheses were followed up over a period of 5-8 years. All the uncemented implants (52 femoral components, 52 patellar components, 54 tibial components) were subjected to radiological analysis of the anchorage zone between prosthesis and bone. The results were evaluated on the basis of the postoperative radiographs and the follow-up radiographs, which were divided into four groups. It was necessary to create a 5th group for radiographs not suitable for evaluation. The use of fluoroscopy is therefore essential in order to ensure that all radiographs can be evaluated. The best results were obtained with the uncemented femoral prosthesis. Complete "incorporation" with close contact between prosthesis and bone was observed in all cases, even if implantation was not optimal. Radiological loosening of the uncemented patella occurred in 3 patients, and it was necessary to perform one patellectomy 6 years postoperatively. In the case of the tibia implant, the follow-up showed radiological "incorporation" of the prosthesis in all cases with technically adequate implantation: the tibia implant was inadequately implanted in 8 cases. Radiological loosening of the tibia implant was observed in 4 of these 8 patients. There was a higher rate of radiological failure in the group of patients over 70 years of age, and among patients whose primary disease was primary chronic polyarthritis. However, given technically exact implantation, satisfactory results could be obtained even in these two groups. Clinical pains occurred only several years after evidence of radiological loosening. Radiological follow-up analysis therefore offers a means of obtaining early information about the prosthesis-bone interface of uncemented total knee-joint endoprosthesis.     

Reconstruction of the rotation center of the hip after oblong cups in revision total hip arthroplasty

Background

The preoperative bone defect and the reconstruction of the center of rotation of the hip are critical in acetabular revision surgery. Uncemented oblong cups are employed in order to manage these issues. We analyzed the clinical results and rates of revision of two different uncemented oblong cups, the reconstruction of the center of rotation of the hip, as well as the rate of radiological loosening and possible risk factors.

Materials and methods

Forty-five patients (46 hips) underwent acetabular revision surgery using two different uncemented oblong cups. We assessed the clinical results and the survival rate for revision and aseptic loosening. Intraoperative bone loss was classified according to Paprosky, and acetabular reconstruction was assessed according to Ranawat. The mean follow-up was 7.2 years (range 4–11 years).

Results

There were four re-revisions (three due to aseptic loosening); the survival rate for re-revision due to aseptic loosening was 60.1 % at seven years. The mean distance between the center of the femoral head prosthesis and the approximate center of the femoral head improved from 21.5 to 10.2 mm. Thirteen cups showed radiological loosening; the survival rate for radiological loosening at seven years was 40.54 %. A smaller postoperative horizontal distance was correlated with cup loosening.

Conclusions

Although optimal acetabular reconstruction can be achieved by using oblong uncemented cups in revision hip surgery, the clinical and radiological results are not encouraging. Excessive medialization of the cup may increase the rate of loosening.     

Metastatic lesions of the humerus treated with the isoelastic diaphysis prosthesis

Between January 1, 1987, and December 31, 1997, an isoelastic polyacetal resin prosthesis was used in 50 patients with metastatic bone disease to reconstruct pathologic or impending fractures of the humeral diaphysis. Fifty-seven operations were performed, including seven revision surgeries. The patients were assessed before and after surgery for limb function and quality of life using a modified Karnofsky scale. The mean survival time was 440 days. Ninety-one percent of the operations resulted in restoration or improvement of quality of life. Limb function was good or excellent in more than 80% of the patients after surgery. Breaking of the implant (n = 3), loosening of the implant (n = 2), periprosthetic fracture (n = 1), hematoma (n = 2), infection (n = 1), and one radial nerve paralysis were the main complications. In the cases of implant failure, the prosthesis broke at the site of a locking screw that was inserted across the prosthetic shaft in the cementless implantation technique. This kind of complication could be avoided by using bone cement for implantation or additional plate osteosynthesis between the prosthesis and humeral shaft. The isoelastic diaphyseal prosthesis offers a promising method of treating patients with metastatic lesions of the humeral shaft.