Bank bone grafts in revision hip arthroplasty for acetabular protrusion

In 23 revision hip arthroplasties in which acetabular protrusion was encountered, homologous bone grafting was used to reconstruct or reinforce the medial wall of the acetabulum. Loosening of the acetabular component was the cause of the protrusion in all the cases. Postoperative follow-up showed a solid bone socket around the acetabular cup in all the cases and no signs of loosening at 3-years' follow-up.     

Bank bone grafts in revision hip arthroplasty for acetabular protrusion

In 23 revision hip arthroplasties in which acetabular protrusion was encountered, homologous bone grafting was used to reconstruct or reinforce the medial wall of the acetabulum. Loosening of the acetabular component was the cause of the protrusion in all the cases. Postoperative follow-up showed a solid bone socket around the acetabular cup in all the cases and no signs of loosening at 3-years' follow-up.     

Mechanical characteristics of impacted morsellised bone grafts used in revision of total hip arthroplasty

The use of impacted, morsellised bone grafts has become popular in revision total hip arthroplasty (THA). The initial stability of the reconstruction and the effectiveness of any subsequent process of revitalisation and incorporation will depend on the mechanical integrity of the graft. Our aim in this study was to document the time-dependent mechanical properties of the morsellised graft. This information is useful in clinical application of the graft, in studies of migration of the implant and in the design of the joint. We used 16 specimens of impacted, morsellised cancellous bone from the sternum of goats to assess the mechanical properties by confined compression creep tests. Consideration of the graft material as a porous, permeable solid, filled with fluid, allowed determination of the compressive modulus of the matrix, and its permeability to fluid flow. In all specimens the compression tests showed large, irreversible deformations, caused by flow-independent creep behaviour as a result of rolling and sliding of the bone chips. The mean permeability was 8.82 *10(-12) m4/Ns (SD 43%), and the compressive modulus was 38.7 MPa (SD 34%). No correlation was found between the apparent density and the permeability or between the apparent density and the compressive modulus. The irreversible deformations in the graft could be captured by a creep law, for which the parameters were quantified. We conclude that in clinical use the graft is bound to be subject to permanent deformation after operation. The permeability of the material is relatively high compared with, for example, human cartilage. The confined compression modulus is relatively low compared with cancellous bone of the same apparent density. Designs of prostheses used in revision surgery must accommodate the viscoelastic and permanent deformations in the graft without causing loosening at the interface.     

Supportive strut grafts for diaphyseal bone defects in revision hip arthroplasty

Large femoral cortical strut allografts were used to provide structural support of the femur in 20 patients in whom uncemented, extensively porous-coated, press-fit revision femoral stems were applied. The mean followup was 4.7 years. Radiographic analysis of the patients who had revision surgery revealed that in all 20 patients, the cortical femoral strut allografts showed incorporation. Small areas of graft resorption were observed in only two patients. Seventeen of the uncemented femoral revision stems radiographically showed bone ingrowth. Three of the revision femoral stems were interpreted as being fixed only by fibrous ingrowth after early subsidence after surgery. There were no reoperations. Before surgery, all patients were unable to walk and had severe pain. At followup, all patients were ambulatory and had considerable improvement in pain relief and in their ability to walk. The mean Harris hip score after surgery was 75 (range, 57.5-92). Complications consisted of one peroneal nerve palsy, which resolved; one deep venous thrombosis; one gastrointestinal ulcer; and one case of pneumonia. Supportive cortical strut allografts represent an alternative to the use of circumferential bulk allografts and total femoral replacements in patients with large combined proximal and diaphyseal bone defects.     

Failure of bulk bone grafts after total hip arthroplasty for hip dysplasia

Introduction

Bulk bone grafts are used in total hip arthroplasty (THA) when adequate acetabular cup coverage cannot be achieved. Data from literature show mainly good short-term and mid-term results with contradictory long-term results. The aim of this study was to investigate acetabular cup stability and graft integrity after dysplastic adult hip reconstruction with total hip endoprosthesis and bulk bone graft for acetabular deficiency.

Methods

Seventy-two hips in 64 patients that underwent THA with bone autograft or allograft were assessed immediately after operation, 6 months and 1, 2, 3 and 10 years after operation. Acetabular angle, acetabular cup coverage, bone graft width, and bone graft height were measured and questionnaire was designed to determine acetabular cup stability and grade graft integrity. Four investigators graded grafts and inter-rater and intra-rater reliability of the questionnaire was tested.

Results

All measured parameters in all patients and in patients with autograft and those with allograft separately showed significant changes consistent with graft failure and acetabular cup instability when level of significance was set at p < 0.05.

Conclusions

Results of this study show significant decrease in acetabular cup stability when either autograft or allograft is used for cemented acetabular reconstruction of dysplastic hip. Further, allografts showed twice as rapid failure as autografts. Although these results contradict both good short-term and long-term results in published literature, they present warning for future use of free bulk bone grafts in reconstructive hip surgery.     

全髋翻修术中髋臼骨缺损翻修重建

全髋关节置换术后髋臼失败的翻修重.是骨科医生面临的巨大的技术挑战.翻修时面对广泛的髋臼骨缺损,可能需要采用几种不同技术,尽可能使髋臼侧恢复到初次全髋关节置换术时的骨量.获得翻修假体初始稳定是翻修手术成功的关键.该文就全髋翻修术中髋臼骨缺损的分类、术前计划和翻修重建策略作一综述.     

Conversion total hip arthroplasty: Primary or revision total hip arthroplasty

Total hip arthroplasty (THA) is an increasingly common procedure among elderly individuals. Although conversion THA is currently bundled in a diagnosis related group (DRG) with primary THA, there is a lack of literature supporting this classification and it has yet to be identified whether conversion THA better resembles primary or revision THA. This editorial analyzed the intraoperative and postoperative factors and functional outcomes following conversion THA, primary THA, and revision THA to understand whether the characteristics of conversion THA resemble one procedure or the other, or are possibly somewhere in between. The analysis revealed that conversion THA requires more resources both intraoperatively and postoperatively than primary THA. Furthermore, patients undergoing conversion THA present with poorer functional outcomes in the long run. Patients undergoing conversion THA better resemble revision THA patients than primary THA patients. As such, patients undergoing conversion THA should not be likened to patients undergoing primary THA when determining risk stratification and reimbursement rates. Conversion THA procedures should be planned accordingly with proper anticipation of the greater needs both in the operating room, and for in-patient and follow-up care. We suggest that conversion THA be reclassified in the same DRG with revision THA as opposed to primary THA as a step towards better allocation of healthcare resources for conversion hip arthroplasties.     

嵌压植骨技术在人工全髋关节翻修术中的应用

目的 探讨使用嵌压植骨技术进行全髋关节翻修术的临床效果。方法1998年12月至2003年9月,采用嵌压植骨技术对48例患者72侧髋关节进行了翻修,平均随访时间25个月,采用Harris评分及X线片观察进行临床疗效评定,并统计并发症的发生率。结果Harris评分从术前平均44．6分提高到术后87．4分,术后优良率为达90．3％;无假体松动及下沉;股骨骨折发生率为4．2％;关节脱位率为1．4％,感染率为1．4％。结论嵌压植骨技术是一种有效重建髋关节置换术后松动所致严重骨缺损的方法。采用冻干异体骨植骨及解剖柄股骨假体同样可以获得满意的临床效果。     

Management of acetabular bone loss in revision total hip arthroplasty

Most acetabular revisions can be managed with a hemispherical component with screw fixation. Areas of segmental bone loss that preclude acetabular component stability may be managed with structural allograft or second-generation porous metal augments. Acetabular cages have a limited application but can be a useful tool in the management of massive bone loss and pelvic discontinuity.     

One-stage revision of infected total hip arthroplasty with bone graft

There are many different opinions in the literature regarding the best procedure for revision of infected hip arthroplasty and hence in achieving long-term stabilization of a new implant. Thirty-two patients with 32 loose and infected total hip arthroplasties underwent revision with a bone graft in a 1-stage procedure. The bone graft was used in the acetabulum and femur in 25 patients, in the acetabulum alone in 4 patients and in the femur alone in 3 patients. A metal mesh was necessary in 15 patients to contain the morselized bone graft. At the time of surgical revision, 9 patients had a draining sinus, 6 had a closed sinus, and 17 had never had sinuses in the surgical wound. Antibiotic therapy was administered intravenously and orally for 6 months. Mean follow-up was 103 months (range, 63-183 months), and infection recurred in 2 (6.2%) cases. Further studies are necessary, and continuation of this method is justified.     

Use of freeze-dried bone allografts in revision total hip arthroplasty

Acetabular loosenings with severe bone loss require a large amount of graft material to fill the defect. Although all donors are systematically subjected to serologic screening, bone allografts that are chemically processed, freeze-dried, and radiosterilized ensure a higher level of microbiological safety than radiosterilised deep-frozen allografts. The bone allograft used in this study meets this requirement. Therefore, it was both interesting and important to evaluate its outcome in revision acetabuloplasty. This phase II multi-centre study involves 44 revision total hip replacements (35 evaluable) in patients with acetabular bone defects who received allografts obtained from femoral heads harvested from living donors. The results obtained at 40 months follow-up confirmed that reconstructions using a small amount of graft material have a satisfactory outcome. Where an allograft is used in association with an acetabular ring, good primary stability is provided by the ring and secondary stability is ensured by graft incorporation (which, in our study, has often shown to be enhanced by the use of bone cement). The advantages of this type of bone allograft are its greater ease of use and storage at room temperature.     

Transfemoral approach for revision total hip arthroplasty

We performed revision total hip arthroplasty on 12 patients via the transfemoral approach because difficulty with surgery was anticipated preoperatively. The total hip score improved in all of the patients. Radiographically, there were no radiolucent lines around the acetabular and femoral components, but one hip still showed sinking of the stem by 2 cm. Although the transfemoral approach might seem very aggressive, this is actually a relatively simple method that allows rapid removal of the prosthesis and cleaning of the medullary canal.     

Preoperative planning for revision total hip arthroplasty

Perioperative complications and unexpected findings at surgery are much more common in revision total hip arthroplasty (THA) compared with the primary setting. The surgeon often is faced with problems during surgery that require special instruments, implants, bone grafts, or other accessories that frequently are not available unless the potential need for these items was anticipated during the preoperative planning process. Anticipation of possible complications also is crucial in the process of informed consent. Patients should be counseled regarding the specific additional risks they face. Preoperative planning is the first and probably the most important step in doing revision THA. An organized approach helps shorten the operative time, minimize risk, decrease the stress level of the surgeon and operative team, and increase the success rate of these complex cases.     

Changing indications for revision total hip arthroplasty

This was a retrospective review of two cohorts of 100 consecutive revisions performed 10 years apart by one surgeon, to determine the major reason for reoperation. For the early cohort, the indications for revision were: loosening of both components (38%), loosening of acetabular component (22%), loose hemiarthroplasty (13%), infection (10%), loosening of femoral component (8%), periprosthetic fracture (6%), recurrent dislocation (2%), and wear (1%). For the recent cohort, the indications for revision have significantly changed: loosening of acetabular component (24%), loosening of femoral component (22%) (p = .0048), recurrent dislocation (16%) (p = .0011), loosening of both components (15%) (p = .0002), wear-osteolysis (7%) (p = .03), infection (7%), loose hemiarthroplasty (6%), and periprosthetic fracture (3%). There has been a change in the indications for revision hip arthroplasty compared with 10 years ago, with a statistically significant increase in revisions for dislocation, wear-osteolysis, and loosening of the femoral component only.     

Preoperative planning for revision total hip arthroplasty

Similar to total hip arthroplasty (THA), preoperative planning is more important for revision THA and includes a thorough clinical evaluation (ie, patient history, physical examination, and laboratory tests, including aspiration and culture) as well as radiographic assessment (ie, for changes in bone loss and quality, for leg length, and for templating to choose the correct components). Similar to primary THA, preoperative planning for revision THA must include the inherent possibility of failure. Careful planning of the current technology and expertise to perform THA will help minimize potential problems. The essence of preoperative planning in revision THA can be summed up simply: Be prepared.     

髋关节置换术后失败原因分析

[目的]分析髋关节置换术后接受翻修手术的病例,探讨髋关节置换术后不同时期失败的原因和特点.[临床资料]回顾性分析1995年6月～2005年6月间髋关节置换术后失败接受翻修手术的病例78例.其中全髋置换术后翻修42例,股骨头置换术后翻修36例.初次髋关节置换术后5年以内翻修的共36例,5年以上翻修的42例.[结果]在早期失败(5年以内)的病例中,失败原因主要是感染(16例),其次是假体无菌性松动,髋臼磨损和机械性失败.在晚期失败(5年以上)的病例中,失败原因主要为无菌性松动,髋臼磨损.[结论]感染是全髋关节置换术后早期松动的主要原因之一.而全髋关节置换术后的主要原因是晚期无菌性松动.     

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。