全髋关节置换术中使用广泛性轻磷灰石涂膜人工股骨干的临床研究

目的探讨广泛性轻磷灰石涂膜人工股骨干用于全髋关节置换术进行中期效果的研究。方法从1998年至2004年，共37例患者在全髋关节置换术中使用了广泛性轻磷灰石涂膜人工股骨干，研究项目包括骨内生长、松脱及翻修手术的原因、其他并发症及广泛性轻磷灰石涂膜人工股骨干的存活率。结果平均手术年龄为62．6岁及平均术后随访为5年。在术后4年，1例（2．7％）人工股骨干因深层感染需要拆除，它当时已经是固定良好。在术后1．6年及6．3年，分别有2例（5．4％）出现无菌性松脱沉降需要做翻修术；另外有1例（2．7％）因有其他的临床问题没有翻重修术。3例松脱沉降的患者都在前14例中出现。这3例松脱患者，在x光检查中发现股骨干的尺码相对股骨较细小因而引致松脱。机械式的失败率为8．1％，81％的股骨干被分类为稳定而有骨内生长。如果端点为翻修手术及放射照片松脱，广泛性轻磷灰石涂膜人工股骨干的9年存活率分别为91．2％及93．9％。结论广泛性轻磷灰石涂膜人工股骨干的临床效果可以与广泛性多孔涂膜人工股骨干相媲美。但是，精通手术植入的技巧需要较长时间掌握。     

应用羟基磷灰石喷涂解剖型股骨假体的中期随访结果

Objective To observe the clinical and radiographic outcomes following the THA using a hydroxyapatite-eoated anatomic stem. Methods From 2001 to 2003, 90 total hip arthroplasty were per-formed in 75 patients using a hydroxyapatite-coated anatomic stem. There are 49 males and 26 females, with the mean age of 58.4 years, range from 42 to 68 years. The mean follow-up period was 7.2 years (5 to 8 years). All patients were evaluated clinically using Harris hip score; preoperative and follow-up radiographs were made. Results Forty-eight patients with 56 hips were involved in this study. There were 29 males and 19 females were included. No patients had underwent revision arthroplasty or aseptic loosening. Accord-ing to the Harris hip score, the average hip score increased from 28.23=6.3 before operation to 93.23±4.8 one year after operation and to 91.6±4.5 at the final review. There was significant difference between the Harris scores at final review and preoperative ones, but no difference one year after operation. All patients had ex-cellent or good results. Three cases were found to be associated with thigh pain. All prostheses were well os-seointegrated. Limited proximal femoral osteolysis occurred in two cases, three cases had radiographic evi-dence of osteosclerosis on the tip of the stem, and six cases were found to represent discontinuous radiolu-cent lines surrounding the stem on the radiographs. No stem subsidence and varus/valgus happened. Con-clusion Hydroxyapatite-coated anatomic stem provided favorable clinical and radiographic results after an intermediate duration of follow-up. The prosthesis had achieved reliable bone ingrowths. The long-term re-sults is needed to be confirmed in future.     

应用羟基磷灰石喷涂解剖型股骨假体的中期随访结果

目的 探讨使用羟基磷灰石喷涂解剖型股骨假体的全髋关节置换术的中期随访结果 .方法 对2001年1月至2003年12月使用羟基磷灰石喷涂解剖型股骨假体的全髋关节置换术患者75例90髋进行中期随访,男49例61髋,女26例29髋;患者年龄42～68岁,平均58.4岁.以Harris评分系统进行临床结果 评估,采用配对t检验分别比较未次随访Harris评分与术前Harris评分、术后早期Harris评分之间的差异;拍摄髋关节正、侧位X线片对影像学结果 进行评估.结果 48例56髋获得随访,男29例35髋,女19例21髋;随访时间5～8年,平均7.2年.随访中无翻修病例.术前Harris评分平均(28.2±6.3)分,术后早期(平均1年)平均(93.2±4.8)分,末次随访平均(91.6±4.5)分,优良率100%.末次随访Harris评分与术前比较差异有统计学意义(P<0.05),与术后早期比较差异无统计学意义(P>0.05).随访期间出现人腿痛3例.X线片显示全部假体均获得稳定的骨长入,出现股骨近端局限性骨溶解2例、假体柄远端骨质硬化3例、假体刷围间断透光线6例,无一例出现假体下沉和假体内外翻.结论 羟基磷灰石喷涂解剖犁股骨假体应用于全髋关节置换术的中期随访结果 满意,假体可以获得稳定的骨长入,但远期疗效有待进一步观察.     

Clinical and radiological outcome of hydroxyapatite-coated femoral stem in revision hip arthroplasty

We used a proximally hydroxyapatite-coated femoral stem in revision arthroplasty of 48 cases with aseptic loosening and Paprosky defect class 1 or 2. We reviewed the outcome after 6.1 (4–9.3) years. The clinical outcome was good, with a mean postoperative HHS of 90 (51–100) points. There were five reoperations all on the acetabular side and none for the femoral stem. At follow-up, we observed cancellous sclerosis radiographically in 19 cases—especially in non-tightly fitted stems and mainly in Gruen zones 2 and 6. In 13 cases, cortical thickening was seen, mainly in Gruen zones 3 and 5 and especially in tightly fitted stems. These bony changes were significant and not related to any clinical parameter. They started to appear from 6 months onward, with increasing frequency with longer follow-up. We find that the standard Mallory–Head hydroxyapatite-coated femoral stem is suitable for revision in cases with lower-class femoral defects.

---

Résumé Nous avons utilisé une tige fémorale enduite dhydroxyapatite proximale dans larthroplastie de révision de 48 cas avec descellement aseptique et défauts osseux de classe 1 ou 2 selon Paprosky. Nous avons examiné le résultat après 6,1 (4–9,3) années. Le résultat clinique était bon avec un score HHS postopératoire moyen de 90 (51–100) points. Il y avait cinq réopérations, toujours pour des problèmes acétabulaires et jamais pour des problèmes de tige fémorale. Àu dernier recul nous avons observé radiologiquement des densifications spongieuses dans 19 cas—surtout pour des tiges imparfaitement ajustées et principalement dans les zones 2 et 6 de Gruen. Dans 13 cas un épaississement cortical a été noté, principalement dans les zones 3 et 5 et surtout pour les prothèses bien ajustées. Ces différences osseuses étaient significatives, sans rapport avec aucun paramètre clinique. Elles ont commencé à paraître à 6 mois avec une fréquence croissante au cours du suivi. Nous trouvons que la tête-Mallory standard–tige fémorale enduite dhydroxyapatite est convenable pour les révisions avec défauts osseux fémoraux de bas grade.

---

---

Study performed at the Rijnland Hospital, Leiderdorp, The Netherlands     

Heterotopic ossification after uncemented hydroxyapatite-coated primary total hip arthroplasty

A total of 134 patients who had a cementless hydroxyapatite-coated total hip arthroplasty (THA) and had no recognized risk factors for heterotopic ossification (HO) were reviewed retrospectively. The average follow-up period was 83 months. Pharmacologic or radiotherapeutic prophylaxis against HO was not used. HO was seen in 90 (67.2%) of the 134 patients reviewed. HO was rated as Brooker class I in 68 (50.7%) patients, class II in 17 (12.7%) patients, class III in 3 (2.2%) patients, and class IV in 2 (1.5%) patients. The average Merle d' Aubigne score in patients with mild forms of HO (Brooker classes I and II) was 16 compared with 13.2 in patients with severe HO (Brooker classes III and IV). A statistically significant negative correlation was found between the presence of HO and the postoperative hip score. Based on our study findings and on a comparison with data in the literature, hydroxyapatite-coated cementless THA alone does not seem to increase the likelihood of HO over other types of THA. The presence of a hydroxyapatite coating does not result in more class III or IV HO, which are the only classes of HO with real clinical significance. Fear of HO should not be a factor in the choice of fixation for THA.     

The use of a high-hip center in revision total hip arthroplasty

In certain cases, primary and revision total hip arthroplasty is complicated by insufficient bone stock and distorted acetabular anatomy such that the craniocaudal dimension of the acetabular recess is greater than the anteroposterior dimension. Acetabular reconstruction in such cases can be carried out by placing the acetabular component more proximally than normal (high-hip center). Recent biomechanical and clinical data suggest that placement of the acetabular component at a higher than normal hip center does not adversely effect the longevity of the component fixation. Proximal placement of the hip center also facilitates the contact between the host bone and the porous coating when uncemented porous coated components are used, and minimizes the need for structural bone grafts. However, femoral components with longer neck lengths and removal of impinging bone are needed when the acetabular components are placed more proximally in order to restore the limb lengths and minimize the chances for dislocation.     

Results of a hydroxyapatite-coated modular femoral stem in primary total hip arthroplasty. A minimum 5-year follow-up

The use of a modular metaphyseal-diaphyseal femoral stem in primary total hip arthroplasty is infrequent. We analyze 94 ESOP (Fournitures Hospitalieres, Heimsbrunn, France) cementless 2-piece modular stems after a minimum 5 years of follow-up. There were 2 aseptic femoral stem loosenings and no cases with thigh pain. Mean femoral canal filling was 90%. Radiographic ingrowth was obtained in 83 (P < .001). At 7 years, the survival rate for femoral aseptic loosening was 97.8% and no stem was at risk for revision (95% confidence interval, 94.8%-100%). This prosthesis provides good clinical results with absence of pain and excellent radiographic results. It is an option in femora with good bone quality. Femoral osteopenia and cortical widening were infrequent, and the modular metaphyseal-diaphyseal junction was not a problem in vivo.     

The use of allograft bone in revision of total hip arthroplasty

Fifty-two frozen bone allografts have been used on 44 patients undergoing revision hip arthroplasties. The average follow-up time on these patients has been 17 months, with a range of six to 72 months. Both proximal femoral allografts and the allografts for the reconstruction of acetabular deficiencies have been used. To date, most patients experience marked pain relief and improvement in function. Though the results attained to date are short-term, the use of allografts in the revision hip arthroplasties represents a natural progression of the tumor work. However, while the early results are encouraging, it remains to be seen how the proximal femur allografts and the large acetabular allografts will behave over a long period of time.     

Simultaneous primary total hip arthroplasty and contralateral revision hip arthroplasty: role for use of femoral head autograft

We report the outcome of revision hip arthroplasty for patients with acetabular bone loss in whom the femoral head retrieved from arthritic contralateral hip during the same anesthesia was used as autograft for acetabular reconstruction. Thirty-two hips in 16 patients with a mean age of 63.8 years (range, 43-79 years) were followed for an average of 3.5 years. All primary arthroplasties were successful. Evidence of autograft incorporation was found in all except 2 patients. The acetabular component failed and required revision in the latter 2 patients. The use of femoral head autograft in a select group of patients with symptomatic arthritis of hip and a failed prosthetic hip with severe bone loss in the contralateral side is a viable option. However, this technique should not be applied to acetabular reconstructions in which protected weight-bearing in the postoperative period may be necessary.     

Clinical results after revision and primary total hip arthroplasty

Results after 184 primary and 227 revision total hip arthroplasties were compared with an emphasis on rates of failure leading to reoperation and intra- and postoperative complications and on the clinical outcome of the nonrevised arthroplasties in the two series. The failure rate was 7% (11 of 156) in the primary series, versus 27% (54 of 195) in the revision series. The rate of complications was substantially higher after revision, due to 16% (36 of 227) intraoperative fractures of the femoral shaft and 6% (14 of 227) postoperative dislocations. Clinical assessment of the nonrevised arthroplasties in the two series revealed no difference with regard to relief of pain. For patients with concomitant disabling conditions functional outcome was inferior after revision, but for patients without such conditions the functional results of the two series were equal. The favorable clinical results of the nonrevised arthroplasties in the revision series must be seen in relation to the very high rate of failure leading to reoperation.     

Intraoperative autologous transfusion in primary and revision total hip arthroplasty

Significant blood loss during total hip arthroplasty is usually unavoidable. Blood loss is even more of a problem during revision total hip arthroplasty. Using the Cell-Saver for retrieval of red blood cells to be used for autotransfusion during surgery is a safe and useful way of sparing donor blood transfusion. This is a retrospective analysis of primary and revision total hip arthroplasty cases and comparison between cases in which Cell-Saver was used versus those in which Cell-Saver was not used. Generally accepted standards to determine the need for blood transfusion, including measured serum hemoglobin and patient symptoms and vital signs, were used as guidelines in treating patients. Using multiple regression models and taking into account certain variables between cases, it was determined that a significant amount of donor blood transfusion can be saved when the Cell-Saver is used. The Cell-Saver is an important aid in intraoperative treatment for both primary and revision total hip arthroplasty cases.     

Modular revision for recurrent dislocation of primary or revision total hip arthroplasty

Two surgeons who used the same implants and surgical approach performed 23 revisions for recurrent dislocation of modular total hip arthroplasty (THA) with retention of components. For 17 primary hips, there was a mean of 3.8 (range, 2-10) dislocations before revision. Fifteen hips had exchange of the acetabular liner, 13 had a change in neck length, and 5 had a change in size of the femoral head. At a mean follow-up of 4 years (range, 2-7 years), 14 patients (82%) had no further dislocation, 1 had 1 additional dislocation, and 2 required additional surgery. For the 6 revision procedures, the mean number of dislocations was 3.8 (range, 2-10) before re-revision. Liner exchange was performed in 4 hips, neck length changed in 3 hips, and head size increased in 2 hips. At a mean follow-up of 3 years (range, 2-5 years), only 3 patients (50%) had no further dislocation, and 2 required additional surgery. Modular revision can be a successful method of treatment of recurrent dislocation after primary THA, but is much less successful after revision THA.     

Early clinical results of hydroxyapatite-coated total hip arthroplasty

A retrospective clinical and radiographic review of 25 conventional cementless total hip replacements (THRs) and 25 cementless hydroxyapatite-coated THRs was performed to evaluate early postoperative results. The hydroxyapatite-coated group had a higher incidence of pain-free arthroplasties compared with the standard cementless group (72% v 44%, P = .045) at the 2-month postoperative evaluation. At the 6-month evaluation, 76% of hydroxyapatite-coated THRs were pain-free compared with 52% of conventional cementless THRs, although the statistical significance disappears (P greater than .05). No differences between groups existed in the 6-month Harris hip scores, average motion, use of external support, Trendelenberg gait, postoperative implant radiolucent lines. Adding a 50- to 75-mug hydroxyapatite coating to a proximal one-third porous femoral prosthesis and porous surface acetabular cup improved the early clinical results in cementless THR. Whether this improvement in pain scores reflects a more stable cementless prosthesis via increased rates and amount of osseus ingrowth or adjunctive bone hydroxyapatite chemical bonding remains unanswered. Long-term follow-up of femoral subsidence and THR revision is needed to indicate the durability and success of hydroxyapatite coating.     

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.     

Threaded acetabular components for primary and revision total hip arthroplasty

A clinical and radiographic review of 48 total hip arthroplasty patients with threaded acetabular components was undertaken at 24-44 months of follow-up study. Twenty-five patients had primary hip arthroplasties and 23 had revision procedures. Clinical scores revealed good to excellent results in 60% of primary and 30% of revision procedures. Radiographic analysis revealed stable acetabular components in 88% of primary and 61% of revision procedures. Potentially loose acetabular components were noted in 8% of primary and 4.3% of revision procedures and loose acetabular components in 4% of primary and 34.7% of revision procedures. The rate of acetabular component loosening was considered unacceptably high in revision cases and an area of concern in primary cases. Discretionary use of these components is advised.     

Hospital resource utilization for primary and revision total hip arthroplasty

BACKGROUND: Previous reports have suggested that hospital resource utilization for revision total hip arthroplasty is substantially higher than that for primary total hip arthroplasty. However, current United States Medicare hospital-reimbursement policy does not distinguish between the two procedures. The purpose of this study was to compare primary and revision total hip arthroplasties with regard to actual hospital resource utilization and to identify clinical and demographic factors that are predictive of higher resource utilization associated with these procedures. METHODS: We evaluated the clinical, demographic, and economic data associated with 491 consecutive unilateral primary or revision total hip arthroplasties performed by two surgeons at a single institution between January 2000 and December 2002. The distributions of various demographic, clinical, and utilization characteristics were compared between the two types of arthroplasty procedures, and multivariable linear regression techniques were used to determine independent patient characteristics that were predictive of higher costs for both the primary and the revision procedures. RESULTS: The mean total hospital cost was $31,341 for the revision procedures compared with $24,170 for the primary procedures (p < 0.0001). The mean operative time was 41% longer for the revisions than for the primary procedures (4.5 hours compared with 3.2 hours, p < 0.0001), the mean estimated blood loss was 160% higher (1348 mL compared with 518 mL, p < 0.0001), the mean complication rate was 32% higher (29% compared with 22%, p = 0.072), and the mean length of the hospital stay was 16% longer (6.5 days compared with 5.6 days, p = 0.0005). A higher severity-of-illness score (a measure of preoperative medical health) was predictive of higher resource utilization for both primary and revision arthroplasty even after adjustment for other factors. Preoperative femoral and ace-tabular bone loss and a diagnosis of periprosthetic fracture were predictive of higher resource utilization associated with revision procedures. CONCLUSIONS: At one institution, hospital resource utilization for revision total hip arthroplasty was found to be significantly higher than that for primary arthroplasty. This information is not reflected by current United States Medicare hospital reimbursement, which is the same for all lower-extremity arthroplasty procedures, regardless of the diagnosis, the complexity of the procedure, or the patient's baseline medical health. If these findings are generalizable to other institutions, appropriate reimbursement formulas should be developed to accurately reflect the true costs of caring for patients with a failed total hip arthroplasty.     

Femoral head autograft in simultaneous primary and revision total hip arthroplasty

Bilateral total hip arthroplasty during one anesthetic procedure can be beneficial in properly selected patients. For patients who have a failed hip arthroplasty requiring revision and a contralateral arthritic hip requiring primary arthroplasty, bilateral surgery permits the resected femoral head from the primary procedure to be used as a fresh autogenous bone—graft during the revision procedure. Four patients underwent combined primary hip arthroplasty and contralateral revision hip arthroplasty during one anesthetic procedure. The femoral head obtained during the primary procedure was used as a structural acetabular bone—graft in three patients, and bone slurry was used to fill cavitary acetabular defects in one patient. A femoral neck autograft was used to reconstruct a calcar defect in one of the patients. After an average follow-up period of 27 months, all hips were functioning well with healed bone—grafts and stable prosthetic components.     

Arthroscopic shaver-assisted total hip arthroplasty revision

A case report of a 54-year-old man who underwent a revision arthroplasty 13 years after his original hip replacement is presented. The patient presented to the clinic with a 2-month history of hip pain. Severe pelvic osteolytic lesions were seen on radiographs. The revision procedure consisted of debridment of the osteolytic lesions and bone grafting. An arthroscopic shaver was used to remove the osteolytic lesions proximal to the acetabular cup. Excellent debridment was obtained. Cortical bone allograft was the used to fill the void areas behind the cup. The patient did well postoperatively with no recurrence of osteolysis as seen on radiographs obtained 7 months after surgery. This report presents a successful case of pelvic osteolytic debridment with the use of an arthroscopic shaver.