Rapid resolution of femoral head osteonecrosis after rotational acetabular osteotomy

The natural history of osteonecrosis of the femoral head is generally thought to be one of progressive deterioration if no intervention is undertaken. However, it is unknown whether surgical intervention is beneficial for patients with a small region of osteonecrosis. We observed rapid improvement of MRI findings after rotational acetabular osteotomy (RAO) was performed in a young patient with osteonecrosis of the femoral head. The band-like low signal area on T2-weighted images almost resolved by six months after surgery. He returned to work as an electrician by six months after surgery. Early surgical intervention such as RAO that alters the mechanical force acting on the necrotic region of the femoral head may accelerate the recovery of osteonecrosis and the improvement of symptoms.     

偏心髋臼旋转截骨术的生物力学机制及初步临床疗效

 目的 探讨偏心髋臼旋转截骨术治疗髋关节发育不良的生物力学机制及其初步临床疗效。方法 取6具经福尔马林防腐处理的女性尸体骨盆标本,建立髋关节生物力学模型,在模型上模拟偏心髋臼旋转截骨术。对骨盆缓慢施加连续纵向压力0~500 N,测量术前和术后载荷100、200、300、400、500 N时的股骨头承重区应变值,计算应力值。2007年7月至2014年10月应用偏心髋臼旋转截骨术治疗髋关节发育不良25例（26髋）,男6例,女19例;年龄11~57岁,平均31岁。术后以Harris髋关节评分评价髋关节功能,摄骨盆正位X线片测量头臼指数、中心边缘角（center-edge-angle,CE角）及Sharp角。结果-随着脊柱纵向压力加大,股骨头上的应力值随之增加。偏心髋臼旋转截骨术后应力值在载荷超过300 N后由上升趋势转变为下降趋势,总体呈抛物线状。100~500 N载荷下偏心髋臼旋转截骨术后的应力值与术前差异均无统计学意义。临床随访18例（19髋）,随访率72%。随访时间7~85个月,平均40个月。Harris髋关节评分由术前（64.3±7.2）分提高至末次随访时（85.6±5.3）分;头臼指数平均增加36.5%、CE角平均增加33.1°、Sharp角平均减少12.3°,与术前比较差异均有统计学意义。结论-偏心髋臼旋转截骨术具有较好的矫正髋臼畸形的能力,可增大股骨头的髋臼覆盖面和降低承重区压力。     

A biomechanical comparison of periprosthetic femoral fracture fixation in normal and osteoporotic cadaveric bone

Several techniques are described for fixation of Vancouver B1 femoral shaft fractures after total hip arthroplasty. Twenty-four femurs were scanned by dual x-ray absorptiometry scanned and matched for bone mineral density. Femurs were implanted with a cemented simulated total hip prosthesis with a simulated periprosthetic femur fracture distal to the stem. Fractures were fixed with Synthes (Paoli, Pa) 12-hole curved plates and 4 different constructs proximally. Each construct was loaded to failure in axial compression. Constructs with locking and nonlocking screws demonstrated equivalent loads at failure and were superior in load at failure compared with cables. Cable constructs failed proximally. No proximal failures occurred in specimens fixed with screws and cables. A combination of locked or nonlocked screws and supplemental cable fixation is recommended for the treatment of Vancouver B1 periprosthetic femur fractures.     

Curved varus femoral osteotomy for minimal dysplastic hip in patients older than 45 years of age: comparison with rotational acetabular osteotomy

Periacetabular osteotomies, such as rotational acetabular osteotomy (RAO) for osteoarthritis (OA) secondary to hip dysplasia, have produced satisfactory medium- and long-term results in early OA. However, as the degree of surgical invasion of these procedures is comparatively major and long-term postoperative rehabilitation is required, this procedure is generally not indicated for those in the fifth and sixth decades of life. Curved varus femoral osteotomy (CVO), which is a less invasive procedure, is considered a worthwhile option, although to the best of our knowledge no comparative study has been reported on these two procedures in older patients. We performed a comparative study on the outcomes of CVO for minimal dysplasia of the hip with a center-edge (CE) angle greater than 5° in 15 patients (15 joints) older than 45 years of age at a mean period of 8 years after surgery and on the outcomes of RAO in 16 patients (18 joints) performed during the same period. No significant difference was observed between the two groups regarding the Merle dAubigne score during follow-up. Progression of osteoarthritis was radiologically observed during follow-up in three hips in the CVO group and in one hip in the RAO group. Kaplan-Meier survivorship analysis, with radiological progression of osteoarthritis as the endpoint, predicted a survival rate of 75% at 10 years in the CVO group. In the RAO group the predicted 10-year survival rate was 94%, demonstrating no significant difference between the two groups. CVO is a less invasive surgical technique than RAO, requires a comparatively shorter period of postoperative rehabilitation, and is useful as a joint-preserving procedure in older patients with minimal dysplasia of the hip with unilateral involvement. CVO should be selected for elderly patients with a CE angle greater than 5°.     

Pathology of femoral head collapse following transtrochanteric rotational osteotomy for osteonecrosis

We investigated the pathology of femoral head collapse following transtrochanteric anterior rotational osteotomy. Six femoral heads were obtained during total hip arthroplasty some 2–12 years after osteotomy. In all cases, the preoperatively necrotic lesions exhibited mostly osteonecrosis with accumulation of bone marrow cell debris and trabecular bone with empty lacunae, although repair tissue such as granulation tissue and appositional bone formation were observed in limited areas in some cases. In the transposed intact articular surface of the femoral head, osteoarthritic changes such as fissure penetration to the subchondral bone and osteophyte formation were commonly observed. In newly created subchondral areas at weight-bearing sites, trabecular thickness and the number of trabecular bones had decreased, with few osteoblasts, osteoclasts, and osteocytes being present, resulting in a coarse lamellar structure of the trabecular bone. These findings suggest that transposed areas in cases of failure consist mostly of low-turnover osteoporotic lesions which could cause collapse of the femoral head. Received: 5 October 1999     

Anterior coverage after eccentric rotational acetabular osteotomy for the treatment of developmental dysplasia of the hip

Background

In periacetabular osteotomy for the treatment of developmental dysplasia of the hip, impairments in ADL due to limitations in hip flexion can occur when anterior displacement is added to lateral displacement in order to obtain sufficient femoral head coverage. This study was conducted to determine, by the range of motion (ROM) simulation based on CT images, the minimum angle of hip flexion and internal rotation at 90° of flexion that is necessary to avoid ADL impairments after eccentric rotational acetabular osteotomy (ERAO) and to estimate the angles of anterior femoral head coverage on plain radiography that enable the above flexion.

Methods

Of 47 hips treated with ERAO at our hospital from December 2007 to May 2012, 27 hips without progressive osteoarthritis which could be CT scanned were examined and included. The mean age at the time of surgery was 40.7 years (SD 1.8). The postoperative follow-up period was 30.2 months (SD 3.6). Two hips were in male patients and 25 hips were in female patients. The disease stage prior to surgery was pre-osteoarthritis in 5 hips, early in 11 hips, and progressive in 11 hips. We checked whether the patients were capable of activities that require deep hip flexion for the evaluation of postoperative ADL. Radiographic examination was performed before and one year after surgery to calculate LCE angle, Sharp angle, AHI, and VCA angle. The angle at which impingement of the displaced fragment of the bone and the femur appeared was measured using 3D CAD software, and the relationship between this angle and the physical findings, ADL impairment, or radiographic findings, were also examined.

Results

22 out of 27 hips that were capable of 116° or more of flexion or 42° or more of internal rotation at 90° of flexion in ROM simulation showed the absence of ADL impairment and a postoperative VCA angle ≤42°, whereas 5 hips with 110° or less of flexion or 40° or less of internal rotation at 90° of flexion in ROM simulation had ADL impairments associated with limitations in hip flexion and a postoperative VCA angle ≥46°.

Conclusions

Anterior and lateral coverage requires a postoperative VCA angle of ≥20° to achieve anterior structural stability and an LCE angle of >25° to obtain adequate superior lateral coverage of the femoral head. A VCA angle ≤42° is required to avoid impingement during deep flexion. A VCA angle ≥46° is a probable risk factor for pincer FAI syndrome after ERAO.     

Severe subluxation of the femoral head after rotational acetabular osteotomy: a case report

We encountered a rare case of severe subluxation of the femoral head after the performance of rotational acetabular osteotomy to treat osteoarthritis of the hip, secondary to acetabular dysplasia. The subluxation was corrected by performing varus and flexion osteotomy.     

Three-dimensional evaluation of acetabular coverage of the femoral head in normal hip joints and hip joints with acetabular dysplasia.

Compared with the assessment by data processing-coupled CT scanning, three dimensional evaluations of the acetabular coverage of the femoral head from a plain X-ray picture of the hip joint is found to be a simpler and easier procedure. In addition, the calculated values agree well with those obtained by CT in reconstruction. Consequently, this method is of great value in evaluating the severity of diseases of the hip joint. The acetabular coverage of the anterior portion of the hip joint is decreased in the elderly even if the hip joint is normal. Because this decrease may result in primary arthrosis deformans, it should be studied further. Rotational acetabular osteotomy (RAO) is a far better method than Salter's for the early stage of coxarthritis. The present study concludes that it is vitally important to maintain the normal ratio of the anterior and posterior coverage and the shape of the acetabular coverage in the treatment of coxarthritis.     

髋臼旋转截骨术时髋臼后上方植骨前后髋关节生物力学的改变及其对比

目的探讨在偏心性髋臼旋转截骨术时于髋臼后上缘旋出部分上方进行植骨并检测植骨前、后髋关节生物力学的变化,为临床进行该类手术时髋臼后上方是否需要植骨提供必要的理论依据。方法将7具人体防腐骨盆标本建立成髋关节发育不良模型,测定每具标本模型髋关节所受应力的初始应变值仅,在每具标本的同一侧做偏心性髋臼旋转截骨术,再测定应变值β,然后,于旋转截骨后的髋臼后上缘旋出部分上方加骨块进行植骨,再测定应变值β’。应用配对资料的t检验比较植骨前后髋关节间应力的改变程度在不同压力负荷时有无差别。结果植骨前后组的对比中,当压力负荷为100N时,t=0．254,P〉0．05;200N时,t=-0．542,P〉0．05,可以认为植骨前后两组问数值差异无统计学意义;但植骨组多数标本的绝对数值要优于非植骨组。结论髋臼旋转截骨后,在髋臼旋出部分后上方进行植骨,能使股骨头所受的应力更趋于合理分布,而且,待植骨块与宿主骨完全愈合后,能较好地增加髋臼后上方骨的储备量。     

髋臼旋转截骨术并发症探讨

目的 总结和分析髋臼旋转截骨术治疗髋臼发育不良的并发症。方法 由同一医生所做７０侧髋关节手术（６３例患者），平均随访３．２年（６个月～６年）。并发症分轻、中和重度三种，将７０侧髋关节手术依手术时间早晚分为前、后期两组，各３５髋，比较两组并发症的发病率并行统计学分析。结果 轻度并发症２５例，占３５．７％；中度７例，占１０％；重度４例，占５．７％，后期手术组的中、重度并发症发病率比前期手术组明显下降，差异有显著性意义（Ｐ〈０．０５）；整个并发症的发病率也明显下降，差异有显著性意义（Ｐ〈０．０５）；轻度并发症的发病率也有下降趋势，但差异无显著性意义（Ｐ＝０．２６）。结论 髋臼旋转截骨术方法复杂。并发症较常见。积累手术经验，提高手术技巧是减少并发症发生的关键。     

Joint space wider than 2 mm is essential for an eccentric rotational acetabular osteotomy for adult hip dysplasia

Background  

Satisfactory intermediate-term results after an eccentric rotational acetabular osteotomy (ERAO) for the treatment of early osteoarthritis secondary to developmental dysplasia of the hip (DDH) have been reported. The purpose of this study was to investigate whether a minimum joint space width (JSW) in patients with advanced osteoarthritis secondary to DDH influences intermediate-term clinical and radiographic outcomes after performing an ERAO.     

Extended proximal femoral osteotomy for severe acetabular protrusion following total hip arthroplasty: A technical note

Exposing and removing the femoral and acetabular components after severe intrapelvic protrusion has occurred can be difficult and dangerous. An extended proximal femoral osteotomy carried distally to the level of the stem lip allows for atraumatic removal of the femoral stem without the need for preliminary dislocation. The exposure afforded by the osteotomy also facilitates acetabular component removal.     

The displacement of the femoral head by rotational acetabular osteotomy. A radiographic study of 97 subluxated hips.

To determine the limits of medial and inferior displacement of the subluxated femoral head by rotational acetabular osteotomy, we studied the acetabular coverage and position of the femoral head radiographically before and after surgery in 97 hips. The median age of the patients at the time of surgery was 33 (18-54) years. The position of the femoral head was represented by its center and medial and upper borders. The average increase and decrease in the CE and the AC angle were 39 degrees and 27 degrees, respectively. The average medial displacement of the head was 8 (-12 to +19) mm measured from its center, and 7 (-10 to +21) mm measured from its medial border. The average inferior displacement was 5 (-6 to +19) mm from its center and 4 (-10 to +15) mm from the upper border. These results indicate that concentric reduction by rotational acetabular osteotomy is limited and that medial displacement of the subluxated femoral head is within similar ranges obtained by other conventional pelvic osteotomies.     

A histological study of articular cartilage after rotational acetabular osteotomy for hip dysplasia

Acetabular dysplasia was produced in 24 immature white rabbits. A rotational acetabular osteotomy was then carried out and radiological and histological studies of the articular cartilage were made.In the hips which did not undergo osteotomy, radiographs at 26 weeks showed that residual subluxation remained and arthritic changes such as narrowing of the joint space or dislocation were still seen. However, in the operated group there was a remarkable increase in cover, but arthritic changes were not observed. After 24 weeks, the Mankin grading score in the operated group was significantly lower than that in the non-operated group. The latter hips showed an irregular surface of the cartilage, exfoliation and proliferation of synovial tissue. In those undergoing osteotomy, primary cloning of chondrocytes or hypercellularity was seen and at 24 weeks after operation and metaplasia of the cartilage in the fibrous tissue was observed in the boundary between the medial area of the acetabulum and the acetabular fossa.     

Results of transtrochanteric rotational osteotomy for femoral head osteonecrosis

Eighteen transtrochanteric rotational osteotomies have been performed in 17 patients for femoral head osteonecrosis (15 patients, Ficat Stage III disease; three patients, Ficat Stage IV disease) during a 51-month period and have 18 to 63 months of follow-up study. The best results were in the posttraumatic and nonsteroid-associated idiopathic cases in patients with small necrotic segments in the weight-bearing region, with no degenerative changes. Failures occurred in patients with large necrotic fragments, preexisting degenerative changes, and steroid- and alcohol-associated etiologies. Although joint arthroplasty was eventually required in ten hips, a period of temporization was achieved sufficient to bring them into the era of cementless hip arthroplasties. Indications for this operation should be restricted to those patients under 40 years of age with late Ficat Stage II or Stage III disease, in which the articular involvement in the lateral roentgenogram is 50% or less.     

Trochanteric rotational osteotomy for osteonecrosis of the femoral head

The rate of success of transtrochanteric rotational osteotomy for osteonecrosis of the femoral head may be improved if patients are preselected using MRI. We have used three criteria for selection for osteotomy (i) minor collapse of the infarcted area, loss of congruity or the crescent sign, without narrowing of the joint space or acetabular involvement (ii) patients younger than 55 years and with a painful hip (iii) patients with an intact area constituting an arc of more than 120 degrees between the central vertical line of the femoral head and the posterior or anterior margin of the necrotic portion as seen on a midsagittal MRI. Seventeen patients were selected, with a follow-up of more than 42 months. A bone scan four weeks after operation showed adequate perfusion of the proximal segment in all hips. The hip score of Merle d'Aubigné et al improved from 13.5 points before operation to 17.2 points at the latest follow-up. Further collapse of the femoral head did not occur. The use of MRI instead of plain radiographs for the selection of patients has improved the success rate of transtrochanteric rotational osteotomy.     

Crossover sign after rotational acetabular osteotomy for dysplasia of the hip

Background  

This study was performed to evaluate whether the radiographic crossover sign influences the painful femoroacetabular impingement or the radiographic progression of osteoarthritis after rotational acetabular osteotomy (RAO).     

Total hip arthroplasty after failed transtrochanteric rotational osteotomy for avascular necrosis of the femoral head

We compared the clinical and radiographic outcome of 15 hips converted to total hip arthroplasty after failed transtrochanteric rotational osteotomy (THA after TRO) for avascular necrosis of the femoral head (ANFH) with that of a matched control group of 16 hips with primary THA for ANFH. The operating time in THA after TRO was significantly longer than that in primary THA. Perioperative blood loss in THA after TRO was significantly more than that in primary THA. Postoperative complications were observed in 4 hips of THA after TRO. The Harris Hip Score, the stability of implants, and survival rates did not significantly differ in both groups. We conclude that TRO did not influence the outcome of secondary THA at short- and middle-term follow-up.     

经股骨粗隆部旋转截骨术治疗股骨头坏死

目的探讨经股骨粗隆部旋转截骨术治疗股骨头坏死的适应证,手术技术及临床疗效.方法 1992年10月～2001年5月,19例23髋股骨头坏死行经股骨粗隆部截骨术.其中男14例,女5例.年龄22～43岁(平均33.4岁).其中酒精性坏死10例12髋、皮质类固醇性坏死6例7髋、创伤性坏死2例2髋、减压病性坏死1例2髋.按Ficat分期,Ⅱ期8例8髋,Ⅲ期11例15髋.术前Harris评分为46～74分(平均56分).术前摄双髋关节正位和屈髋90°,外展45°旋转中立X线片,以确定坏死部位和角度.按日本Sugioka技术,在股骨粗隆部截骨,将股骨头颈及部分粗隆向前或向后旋转(依坏死部位确定),2～3枚松质骨加压螺钉固定.17例19髋获得18个月～11年随访(平均54个月).结果随访时Harris评分为55～94分(平均80.5分),其中大于80分(优和良)14髋,优良率73.2%,小于79分5髋,其中4髋已行全髋关节置换术.股骨头颈旋转角度55°～80°,平均60°.所有患者粗隆部截骨均达骨性愈合,1例大粗隆截骨因加压钢丝断裂不愈合.术中并发症为旋股内动脉断裂1髋,股骨粗隆下骨折2髋.结论经股骨粗隆旋转截骨术可用于选择性治疗股骨头坏死,即坏死区位于负重面,股骨头未被坏死累及面大于1/3,Ficat Ⅱ期和Ⅲ期早期的中青年(<45岁)患者.后旋及加大旋转度效果更好.该手术有一定的技术难度,有较长的学习曲线,应慎重从事.     

Osteophyte of the femoral head after transtrochanteric rotational osteotomy

The relationship between change in the shape of the femoral head and the clinical results after transtrochanteric rotational osteotomy for osteonecrosis of the femoral head was investigated. Fifty-six hips in 50 patients, followed for at least 2 years, showed no progressive collapse and no osteoarthrotic change during that time. The growth of a superolateral osteophyte of the femoral head was observed postoperatively at a higher rate with progression of the preoperative stage. Excessive restoration of the rotated necrotic lesion of the femoral head was observed at a higher rate in hips with the growth of the superolateral osteophyte. The total Japanese Orthopaedic Association score at final follow-up in hips with these shape changes of the femoral head was significantly inferior to the score in hips without these changes. There was a tendency for hips with a low ratio of intact articular surface of the femoral head in the weight-bearing area to the acetabulum just after surgery to manifest these shape changes. Although such changes of the femoral head were considered to represent remodeling to stabilize the hip joint, excessive remodeling could worsen the clinical results. Received: June 10, 1999 / Accepted: December 16, 1999