The Adaptiva custom-made stem—our reasons for not using it anymore

The Adaptiva custom-made stem is a hip stem anchored by fit and fill press-fit into the proximal femur and manufacture is based on computed tomography (CT) scanning. Its concept was developed for primary and revision hip arthroplasty in younger patients in our clinic. We present the advantages and the disadvantages of the system. After 66 months 98.9% of the patients are satisfied with the surgical outcome; 86% attained very good and 9% good results according to the Merle d'Aubigné score. Despite good clinical results and a high satisfaction rate, we stopped using this stem because we do not see any advantages in comparison with standard implants and feel that the price for a custom-made stem for primary hip arthroplasty is too high.     

Results With the Cementless Spotorno Stem in Total Hip Arthroplasty

Increasingly young and active patients are undergoing total hip arthroplasty, making hip prosthesis survival rates an important issue. Cementless total hip arthroplasty provides better prosthesis longevity than does cemented hip arthroplasty, especially in younger patients. Because there is growing support in the literature for tapered geometry in cementless femoral components, we evaluated short-term results for total hip arthroplasty using Cementless Spotorno (CLS) titanium stems. We performed 100 consecutive primary cementless total hip arthroplasties in 87 patients during a 9-year period using CLS stems. Outcome was assessed in terms of survival rate and Harris Hip Score. The stem survival rate was 99%, and the average Harris Hip Score improved from 41 before surgery to 92 at a mean point of 5 years after surgery. Only 1 hip underwent stem revision for a periprosthetic shaft femur fracture caused by high-velocity trauma from a vehicle accident that occurred 6 months after the original surgery. The CLS stems have an excellent survival rate in the short term, especially in younger patients, but long-term studies are required to provide a fuller picture.     

Gute langfristige Nachuntersuchungsergebnisse einer zementierten Titan-Geradschaftprothese

A higher-than-average rate of aseptic loosening has been postulated to be associated with the combination of a titanium stem and bone cement. In this prospective follow-up study we therefore investigated our first consecutive series of 250 implantations of a cemented femoral shaft prosthesis made of titanium alloy (BiCONTACT((R)), Aesculap, Tuttlingen, Germany).Average time of follow-up evaluation was 9.7 years (range 8.7-10.3 years). At follow-up, mean patient age was 81 years; 89 patients with 93 hips have deceased and two could not be located. Follow-up rate was 98.7% for the patients still alive at time of follow-up evaluation. Five patients have been revised, two for infection and one for aseptic loosening of a varus-malaligned stem; two radiologically well-fixed stems had been revised during acetabular revision. Survival estimate showed a calculated cumulative survival rate of 97.5% after 11 years [confidence limits: 99.0% (upper) and 94.1% (lower)]. The average Harris hip score at time of follow-up was 82.25 points.Radiologically, signs of loosening could be detected in 3 stems: in one case varus malalignement deteriorated with time and in 2 cases osteolyses developed together with significant polyethylene wear. All 3 patients experienced only mild pain and revision had not been indicated so far. In conclusion, the long-term follow-up results with this cemented titanium femoral component are encouraging and are comparable to other successful cemented femoral components in primary total hip arthroplasty. No increased risk for aseptical loosening was associated to the combination of titanium and cement in this specific stem. Design parameters seem to play an important role in the development of aseptic loosening in cemented titanium stems.     

Modular noncemented total hip arthroplasty for congenital dislocation of the hip. Case report and design rationale

The highest rate of failure and the greatest technical difficulty in total hip arthroplasty occurs with congenital dislocation of the hip (CDH). Predisposing factors are failure to secure special femoral components to fit an extremely narrow and straight medullary cavity with space for only a very thin mantle of cement. The acetabulum is usually atrophic, and bone grafts are commonly required to support a small-diameter cup. The young age of the average patient and high levels of activity contribute to cement failure. A new modular cementless prosthesis provides excellent immediate skeletal fixation and pain relief in CDH patients. Five modular components are screwed or press-fit into bone. The modular approach facilitates implantation, reduces inventory, and is adaptable to unforeseen problems. These advantages are ordinarily absent with standard or custom cemented components. Modular components may also permit easier revision. The prosthesis is made of titanium alloy for its superalloy strength, elastic modulus, and bioinertness. By omitting the cement mantle, press-fit is obtained with the largest possible implant. The large size minimizes stem breakage in these young, small bones. Excellent short-term results suggest that modular cementless implants are indicated in some patients with CDH.     

Ergebnisse nach Implantation von zementfreien metallspongiösen Hüftprothesen

72 patients having cementless spongy-metal hip prosthesis were reexamined by clinical and radiological check up two to seven years after implantation (average 43 months). In case of five patients hip prosthesis had to be changed due to loosening (no bony ingrowth n=2, loosening of acetabular component due to technical faults n=3). In correlation to clinical results 88% could be considered as excellent or good, 9% acceptable and 3% as inadequate. 10% of the patients complained about tigh pain. The typical radiological bony reactions of the surrounding bone are described. An evaluation of the radiological results can only be done under consideration of the clinical problems involved. In view of the positive results obtained in the recent time the use of spongy-metal hip prosthesis can be recommended for cementless hip joint replacement in case of younger patients. Especially in case of cemented hip joints which have become loose it will be an advantage to use spongy-metal hip prosthesis.     

化脓性髋关节炎后遗骨关节病的人工全髋关节置换治疗

目的对化脓性髋关节炎继发髋关节骨关节病的患者行全髋关节置换术,对其疗效进行评价。方法2000年5月～2005年3月,收治15例化脓性髋关节炎继发髋关节病患者,男7例,女8例;年龄36～56岁。患化脓性髋关节炎时年龄为8～15岁,平均11.3岁。行人工全髋关节置换术治疗时感染静止时间为23～44年,平均29.5年。所有患者术前均有不同程度的关节僵硬,髋关节各方向活动度总和为30～110°。4例患者下肢有2～6cm的短缩,平均3.8cm。2例患者窦道闭合后形成贴骨瘢痕。所有患者均行人工全髋关节置换术。13例采用小型髋臼杯和先髋细直柄假体,2例采用普通假体结合髋臼后上方结构性植骨。股骨侧和髋臼侧均采用生物固定4例,其余患者股骨侧和髋臼侧均为骨水泥固定。骨水泥固定患者术后2周扶拐下地,非骨水泥固定患者术后3～4周扶拐下地,行结构性植骨的2例术后12周下地行步态练习。结果所有患者术中切除组织行细菌培养和病理检查结果均为阴性。4例患肢短缩者术后双下肢长度差距均控制在1.3cm以内。随访16～72个月,平均49个月,Harris评分由术前平均46分,增至术后平均90.5分。随访期内未发生无菌性假体松动和感染复发,无血管神经损伤。结论化脓性髋关节炎后遗骨关节病的患者采用人工全髋关节置换治疗,早期疗效满意,能有效缓解疼痛,解除关节僵硬和患肢短缩等问题。采用特制的小型髋臼杯或自体结构植骨能较好地重建髋臼,必要时选用先髋细直柄假体能较好地解决严重的股骨上段畸形。     

Mid-term results of 155 patients treated with a collum femoris preserving (CFP) short stem prosthesis

Short stem prostheses that preserve the femoral neck are becoming more and more popular. The CFP (collum femoris preserving) has been introduced especially for the treatment of younger patients. However, information about remodelling, complications and learning curve are thus far rare. We present a retrospective study of 155 patients (average age 59.3 ± 9.9 years) who underwent total hip replacement with the CFP prosthesis. Follow-up was obtained 74.3 ± 9.4 months postoperatively. The Harris hip score revealed excellent and good results in 96%. One stem had to be exchanged due to aseptic loosening revealing a survival rate of 99% and 100% for stem and cup, respectively. Radiological analysis showed typical patterns of remodelling with apearance of cortical thickening predominantly in the distal part of the prosthesis. Implant related revision rate was <1%, with further complication rate independent of the surgeon’s individual experience. With regard to outcome, survivorship and complication rate, the medium-term results of the CFP prosthesis are promising.     

Failure of total hip arthroplasty with Boneloc bone cement

Early failure of Boneloc cemented total hip arthroplasty is well documented. However, information regarding the long term prognosis is scanty. The aim of this study was therefore to assess the long term failure rate of total hip replacement with Boneloc bone cement. Between January 1991 and March 1992, Boneloc bone cement (Polymers Recontructive A/S, Farum, Denmark) was used in 42 consecutive total hip replacements in 42 patients. The average age of the patients was 75 years. There were 25 women and 17 men. The diagnosis at operation was osteoarthritis in all cases. A cemented Muller Taperloc femoral stem was used with a cemented Muller acetabular cup (Biomet, Warsaw, USA). The follow-up time was 9 years. All patients underwent radiographic control the first postoperative year and annually after 1995. To date 21 patients have been revised for aseptic loosening at a mean of 5 years (range: one year to 8 years). Three other patients have definite radiographic evidence of loosening. The overall failure rate is therefore 24/42 = 57%. Our results confirm the previously reported poor results of Boneloc bone cement for hip arthroplasty and support the recommendation of indefinite follow-up for surviving prostheses. New prosthesis designs and new cements should have documentation, including laboratory tests and randomized clinical studies with radiostereometric evaluation. However, the ethical responsibility rests heavily on the shoulders of the clinician to make a correct analysis of the need for a new product before he begins to use it.     

Revision hip arthroplasty management tactics--own experience]

INTRODUCTION: Aseptic loosening of hip prosthesis is one of the most serious complications after primary joint arthroplasty. Due to the aging of societies, lengthening of the average life span and increasing number of primary arthroplasty procedures, it can be assumed that the number of revision procedures will be continuously increasing by the year. The aim of the study: presentation of own experience in operative management tactics and early results of treatment after the revision hip arthroplasty. MATERIALS AND THE METHOD: The analysis included 182 patients at the average age of 68, who underwent the revision hip arthroplasty procedure. The procedures of this type were performed most often after cement arthroplasty performed using the Weller's method (45%). The average observation period was 2.3 years. A clinical evaluation of the patients was performed using the Harris scale. A preoperative radiological evaluation was performed using Paprosky classification (for an acetabulum) and Mallory classification (for a femoral bone shaft). Bone defects were evaluated using AAOS classification. A postoperative radiological evaluation was performed on the basis of: radiolucent lines of the acetabulum area in DeLee-Charnley zones and in the area of the endoprosthesis stem in Gruen zones, acetabulum migration and settling of the endoprosthesis stem. RESULTS: During the 2-year observation there were 88.5% of good results reported. According to the Harris scale an improvement was achieved from the average of 46 points before the operation to 85 points after the procedure. 11.5% of bad radiological and functional results were reported including: 11 cases (6.0%) with bad radiological results, and 10 cases (5.5%) with bad clinical results. CONCLUSIONS: Revision hip arthroplasty procedures require individual planning, selection of implants and additional implants. Intraoperative evaluation is required due to lack of an objective image analysis of prosthesis element loosening and a level of bone stock damage determining the scope of the procedure, selection of implants and number of allogenic grafts. Our management tactics is an effective method of aseptic loosening of acetabulum and stem treatment after primary hip arthroplasty.     

Strategies for improving fixation of femoral components in total hip arthroplasty

As strategies are considered for improving fixation of femoral components in total hip arthroplasty (THA), one is challenged to exceed the standard set by contemporary cement procedures. However, despite the improved ten- to 15-year clinical results anticipated with current cementing techniques, the limited fatigue strength of polymethylmethacrylate warrants continued investigation of alternative systems, particularly for younger patients and in revision arthroplasty. Design considerations for femoral stems for cementless THA include (1) initial mechanical stability afforded by the stem shape, (2) strength and stiffness of the stem, and (3) surface features relating to biocompatibility and attachment to bone. In one approach a fit-and-fill algorithm has been implemented to design stems that maximize contact between prosthesis and cortex in priority areas to achieve stability. Titanium is recommended for the fabrication of such stems because of its corrosion resistance, its biocompatibility, and its modulus, which is lower than that of cobalt-chromium alloy. Long-term fixation of these implants will be dependent upon the maintenance of normal strain patterns in the host bone. Achievement of this goal will require additional strategies that combine optimal fit and optimal material properties of the prosthesis.     

Two-stage revision hip arthroplasty for infection with a custom-made, antibiotic-loaded, cement prosthesis as an interim spacer

BACKGROUND: Two-stage reconstruction is a well-recognized treatment for deep infection of hip joint implants. The purpose of the study was to report the results of our treatment using a standardized protocol. METHODS: Forty-two consecutive patients with deep infection of the hip prosthesis were treated according to a prospective, two-stage resection/reimplantation protocol. Between stages, a custom-made, antibiotic-loaded, cement prosthesis was implanted as an interim spacer. RESULTS: Infection was eradicated in 41 patients after the first-stage operation. Thirty-six patients remained with the ability to walk with the interim cement pros-thesis. For 40 patients who underwent reimplantation, recurrence of infection was observed in only 1 patient at an average of 55.2 months' follow-up. CONCLUSION: We have found that our two-stage treatment protocol is a reliable approach for the management of infected hip prostheses. It is effective for eradicating infection and for providing a mobile and functional joint through the treatment course.     

Persistent infection associated with residual cement after resection arthroplasty of the hip

BACKGROUND: The danger of residual bone cement after resection of infected prosthetic components is controversial. PATIENTS AND METHODS: We analyzed 10 patients with infected total hip prosthesis who had been treated previously with resection arthroplasty and antibiotics and who had persistent infection with residual cement. In 9 patients, surgical debridement with resection of all the PMMA was performed, and adequate intravenous antibiotics were administered. 1 patient refused surgical treatment, but accepted antibiotics. RESULTS: At an average of 4 (1-18) years of follow-up, 8 patients had no signs or symptoms of recurrent infection. 1 severely immunodeficient patient died 2 years after the removal of residual cement, for reasons other than his hip. The patient who refused surgical treatment continues to have an active sinus 4 years after first consultation. INTERPRETATION: Residual cement may be responsible for chronic infection. At resection arthroplasty, as part of the treatment of an infected hip arthroplasty, all devitalized or foreign material must be removed.     

Stress distribution in the ulna following a hinged elbow arthroplasty. A finite element analysis

The failure rates for total elbow arthroplasty, in comparison to those for hip arthroplasty, are quite high, and a precise understanding of the underlying causes still remains elusive. The presence of abnormal stresses is a known factor that accelerates loosening of hip and knee arthroplasties. Although a large number of biomechanical studies have led to a better understanding of elbow joint kinetics, very little is known about the stress distribution in this joint. The implantation of a Coonrad humeral component increases stresses in the bone and cement adjacent to the stem tip and hinge regions. An analysis of implanted ulnar stresses and a comparison of those stresses to implanted humeral stresses would improve our understanding of hinged elbow arthroplasty. For this reason, the distribution of mechanical stresses in the ulna are investigated in this study. Using a specially developed casting and sectioning technique, three-dimensional finite element meshes were obtained from an intact human cadaver ulna and an ulna fitted with a Coonrad prosthesis. The material properties were derived from values presented in the literature. Stress distributions in response to axial compression, axial torque, and anteroposterior (AP) force were computed. The cancellous bone and cement regions adjacent to the stem tip of the prosthesis exhibited higher stresses than those in the same regions of the intact case. The higher stresses in the ulna with an implanted prosthesis, as compared to the intact model, might initiate loosening or failure of the prosthesis. The stresses in the cortical bone region adjacent to the prosthesis head were decreased. This is consistent with the clinical observations of bone atrophy following total elbow arthroplasty.(ABSTRACT TRUNCATED AT 250 WORDS)     

Periprosthetic femoral fractures treated with a modular distally cemented stem

PURPOSE: To assess the treatment outcome of revision hip arthroplasty for Vancouver type B3 periprosthetic femoral fractures using a modular distally cemented stem. METHODS: 22 men and 14 women (37 hips) aged 66 to 79 (mean, 70) years underwent revision hip arthroplasty for Vancouver type B3 periprosthetic femoral fractures. The indication for surgery was periprosthetic fracture with stem loosening and loss of proximal bone stock. The patients were referred from other hospitals after previous surgeries had failed: 8 with 3 previous surgeries, 19 with 2, and 9 with one. Using a transtrochanteric approach, the existing prosthesis was removed and a modular proximal femoral replacement stem was inserted, bypassing the area of proximal femoral fracture and bone loss. The stem was distally cemented. Patients were immobilised within 48 hours of surgery. RESULTS: Patients were followed up for a mean of 14 (range, 8-18) years. The mean Harris hip score improved from 29 (range, 5-40) to 78 (range, 56-88); 24 patients attained excellent or good scores (>80), 10 attained fair, and 2 attained poor scores. The mean healing time was 7 (range, 6-14) months; there was no non-union. Improvement in proximal bone stock was noted on serial radiographs. None of the stems had cement fracture or migration, requiring revision. Two (5%) of the patients had dislocations. CONCLUSION: Vancouver type B3 periprosthetic femoral fractures can be successfully treated with a distally cemented modular proximal femoral replacement prosthesis.     

Migration of the Femoral Stem in Hip Arthroplasties: Analysis of Associations with Structural,Radiological and Follow-up Variables

Medial and/or distal migration of the prosthetic stem was found in 63 out of 337 patients (19 per cent) treated surgically with a Christiansen hemiprosthesis, a Christiansen total hip prosthesis or a Charnley total hip prosthesis.

Fractured bone cement, radiolucent zones at the cement/bone interface, resorption of the femoral calcar and cortical sclerosis were all associated with migration. Varus position of the Christiansen total hip prosthesis was significantly associated with medial migration, and a short stem was significantly associated with distal migration. The other structural variables could not be linked with migration. Distal migration was pain-inducing and was significantly associated with late infection. Medial migration had a less distinct association with pain, and was not correlated with infection. Both medial and distal migration were time-dependent, and 4 or more years after operation about 25 per cent of the prosthetic stems had migrated.     

Cementless uncoated polyethylene acetabular components in total hip replacement. Review of five- to 10-year results

We reviewed the results of 545 consecutive total hip replacements using a cementless non-coated high-density polyethylene acetabular component combined with a cemented Müller stem at five to 10 years. In all, 421 patients (445 hips) were available for review, 118 by questionnaire and 303 by examination and radiography. Of these, 86% had a good or excellent result. We found a high rate of radiological loosening of the cup after the sixth year, and a high rate of clinical loosening after the eighth year. Loosening was commoner in women, in younger patients and where a smaller size of acetabulum had been used. Calcar resorption was significantly related to loosening of the acetabulum. Loosening appeared to be mainly due to polyethylene debris produced by micro-movement of the acetabulum against the bone, which had resulted in a giant cell foreign body reaction and subsequent bone erosion. We have abandoned the use of this prosthesis and suggest that direct contact between bone and polyethylene should be prevented by a coating of metal or some other material.     

Design and first clinical results with the ZMR taper revision prosthesis

AIM: The purpose of this study was to survey and to evaluate the first clinical and radiological results with the cementless ZMR taper hip prosthesis. METHOD: The modular distal-tapered stem was designed with a roughened titanium surface and sharp splines to achieve secure distal fixation and rotational stability. 90 ZMR taper hip prostheses were implanted between October 1999 and July 2002. Out of these, 4 interventions were primary and 86 were revision procedures. In 43 cases a complete hip prosthesis revision and in 43 cases a stem revision was necessary. The mean age of the 90 patients (42 males, 48 females) was 67.1 years. The mean follow-up period was 7.6 months (3 to 25 months). RESULTS: The stem displayed an excellent distal fixation. The mean subsidence could be measured with 4.3 mm. Furthermore, most cases showed a particularly favourable remodelling of the proximal femoral bone stock. Complications associated with revision included intraoperatively 4 femur fractures, 3 femur fissures, 5 femur perforations, 2 trochanter fractures and postoperatively 19 dislocations, 5 superficial wound infections, 2 transient palsies, 1 pulmonary embolism, 1 stem rotation and 4 wound healing failures. Considering these complications 15 re-revisions were necessary and the ZMR taper hip prosthesis had to be exchanged in 3 cases. CONCLUSION: On the one hand the ZMR taper hip prosthesis proved its value, particularly with regard to the stem modularity, the excellent distal fixation in conjunction with the possibility of partial body weight bearing and the rapid bone remodelling of the femur. On the other hand an increased number of postoperative complications and re-revisions occurred. Further long-term studies seem to be essential.     

Can Plate Osteosynthesis of Periprosthethic Femoral Fractures Cause Cement Mantle Failure Around a Stable Hip Stem? A Biomechanical Analysis

Periprosthetic femoral fractures (PFF) are a serious complication after total hip arthroplasty. Plate fixation with screws perforating the cement mantle is a common treatment option. The study objective was to investigate hip stem stability and cement mantle integrity under dynamic loading. A cemented hip stem was implanted in 17 composite femur models. Nine bone models were osteotomised just distal to the stem and fixed with a polyaxial locking plate the other eight constructs served as the control group. All specimens were tested in a bi-axial material testing machine (100 000 cycles). There were no statistically significant differences in axial nor in medial (varus) stem migration. No cement cracks were detected in both groups. Plate fixation of a PFF with a stable, cemented prosthesis did not lead to cement mantle failure in this in vitro study.     

Comparison of total hip arthroplasty performed with and without cement : a randomized trial

BACKGROUND: This study was designed to compare the fixation of a Mallory-Head total hip prosthesis with and without cement. METHODS: Two hundred and fifty patients with osteoarthritis of the hip were randomized to receive a Mallory-Head total hip prosthesis designed for insertion with cement or the same prosthesis designed for insertion without cement. Neither the patient nor the outcomes assessor was aware of the type of prosthesis. Outcomes were assessed with respect to mortality, revision arthroplasty, health-related quality of life (evaluated with the Harris hip score, Merle d'Aubign and Postel hip score, McMaster-Toronto Arthritis Patient Preference Disability Questionnaire (MACTAR), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and the time trade-off technique), and the six-minute-walk test. Patients were seen at three, six, and twelve months and yearly thereafter. RESULTS: The prosthesis was inserted with cement in 124 patients and without cement in 126 patients. The mean age of the patients was sixty-four years, 48% were female, and the mean duration of follow-up was 6.3 years. There were thirteen revisions in the group that had fixation with cement and six in the group that had fixation without cement (p = 0.11), and more femoral components were revised in the group that had fixation with cement (twelve versus one; p = 0.002). All health-related quality-of-life measures improved postoperatively in both groups. CONCLUSIONS: In this randomized trial, the group that had the cemented Mallory-Head hip prostheses required more revisions of the femoral component than did the group with the cementless Mallory-Head prostheses, which was perhaps related to the titanium-alloy femoral stem. Our findings are specific to the implants evaluated in this study.     

Effect of osteonecrosis on bone density and its management on the results of revision arthroplasty of the hip]

128 hips after revision arthroplasty in 115 patients which had been operated in our Ward in 1990-2001 were retrospectively evaluated. There were 99 women and 16 men with mean age: 68.9 years old. The mean time of follow-up was 28.6 months (form 3 to 120 months). In 98 hips there were aseptic loosening of the both elements of the prosthesis, in 13 hips there were aseptic loosening of the stem, in 17 hips there were aseptic loosening of the cup only. Cement total hip rearthroplasty was made in 112 cases and cementless total hip rearthroplasty was made in 16 hips. In presented material there were used the acetabular bone grafts in 114 cases, and the femoral bone grafts in 97 cases--all with allogenic frozen bone grafts. The additional implants were used in 31 cases (meshwork, wire, screw). The bone defects in acetabulum and femoral stem was based on Paprovsky classification. There were good and excellent results in 90% and poor or bad results in 10% according to clinical and radiological evaluation. Mean clinical result was 78.5 p. in Harris Hip Score. The radiological results were poor in 13 hips (according to criterion proposed by joined committee of The Hip Society, SICOT and AAOS). Osteointegration of bone allografts was radiologically confirmed in 81% of cases. Complication rates is 20%. There is no correlation between the type of acetabular or femoral bone defects and results of revision hip arthroplasty. Poor results are correlated with use of SKT or Weller stem. Wagner femoral osteotomy and the lack of bone allografts healing.