In 2012 we reviewed a consecutive series of 92 uncemented THRs performed between 1986 and 1991 at our institution using the CLS Spotorno stem, in order to assess clinical outcome and radiographic data at a minimum of 21 years. The series comprised 92 patients with a mean age at surgery of 59.6 years (39 to 77) (M:F 43;49). At the time of this review, seven (7.6%) patients had died and two (2.2%) were lost to follow-up. The 23-year Kaplan–Meier survival rates were 91.5% (95% confidence intervals (CI) 85.4% to 97.6%; 55 hips at risk) and 80.3% (95% CI, 71.8% to 88.7%; 48 hips at risk) respectively, with revision of the femoral stem or of any component as endpoints. At the time of this review, 76 patients without stem revision were assessed clinically and radiologically (mean follow-up 24.0 years (21.5 to 26.5)). For the 76 unrevised hips the mean Harris hip score was 87.1 (65 to 97). Femoral osteolysis was detected in five hips (6.6%) only in Gruen zone 7. Undersized stems were at higher risk of revision owing to aseptic loosening (p = 0.0003). Patients implanted with the stem in a varus position were at higher risk of femoral cortical hypertrophy and thigh pain (p = 0.0006 and p = 0.0007, respectively). In our study, survival, clinical outcome and radiographic data remained excellent in the third decade after implantation. Nonetheless, undersized stems were at higher risk of revision owing to aseptic loosening. Cite this article: Bone Joint J 2014;96-B:455–61

Introduction. Many finite element (FE) studies have been performed in the past to assess the biomechanical performance of TKA and THA components. The boundary conditions have often been simplified to a few peak loads. With the availability of personalized musculoskeletal (MS) models we becomes possible to estimate dynamic muscle and prosthetic forces in a patient specific manner. By combining this knowledge with FE models, truly patient specific failure analyses can be performed. In this study we applied this combined technique to the femoral part of a cementless THR and calculated the cyclic micro-motions of the stem relative to the bone in order to assess the potential for bone ingrowth. Methods. An FE model of a complete femur with a CLS Spotorno stem inserted was generated. An ideal fit between the implant and the bone was modeled proximally, whereas distally an interface gap of 100μm was created to simulate a more realistic interface condition obtained during surgery. Furthermore, a gait analysis was performed on a young subject and fed into the Anybody™ MS modeling system. The anatomical data set (muscle attachment points) used by the Anybody™ system was morphed to the shape of the femoral reconstruction. In this way a set of muscle attachment points was obtained which was consistent with the FE model. The predicted muscle and hip contact forces by the Anybody™ modeling system were dynamic and divided into 37 increments including two stance phases and a swing phase of the right leg. Results. The magnitude and path of interface micromotions was heavily dependent on the location on the implant. In the proximal region, a unidirectional pattern was visible in proximal-distal direction (max. motion was 39μm). Mid stem micromotions were very small (in the order of 4μm), whereas in the distal region, micromotions had a tendency to develop in anterior-posterior and medial-lateral direction (max. motion was 96μm). Hence, in this example, ingrowth is most likely to start in the mid-region. Conclusion. By combining finite element models with musculoskeletal models more realistic, dynamical simulations can be generated to assess the biomechanical behavior of prosthetic components. Both, FE models as well as MS models can be personalized, which offers the possibility to perform truly patient specific predictions. Furthermore, by performing personalized MS and FE calculations, a database is established containing variability of kinematic, force and reconstructive parameters in patients. With this database new implants can be tested in a more robust and reliable manner than before, thereby reducing the chance that innovative ‘defective’ implants are launched on the market

Introduction: High survival rates have been reported for the uncemented CLS Spotorno stem up to 20 years. To confirm survival at longer follow-up we report the minimum 20-year (mean, 22 years; range, 20–25 years) results using this device. Methods: We retrospectively evaluated the clinical and radiographic results of a consecutive series of 354 total hip arthroplasties using an uncemented grit-blasted, tapered femoral stem (CLS Spotorno) in 326 patients. Mean time of follow-up evaluation was 22 years (range, 20–25 years), mean age at surgery was 57 years (range, 13–81 years). Clinical results were evaluated using the Harris Hip Score. Kaplan-Meier survivorship analysis was used to determine long term outcomes for different end points. Results: At final follow-up, 126 patients (136 hips) had died, and 7 patients (8 hips) were lost to follow-up. Forty-one hips (12%) in 38 patients underwent femoral revision – 10 (3%) for infection, 12 (3%) for late periprosthetic fracture, and 19 (5%) for aseptic loosening of the stem. Kaplan-Meier analysis, with revision of the femoral component for any reason as the end point, revealed that the survival rate at 22 years was 86% (95%-confidence limits, 82%–90%). The survival rate with femoral revision for aseptic loosening as the end point was 93% at 22 years (95%-confidence limits, 90% – 96%). Discussion and Conclusion: The long-term results with this type of uncemented femoral component are encouraging and compare to the best reported series in primary cemented total hip arthroplasty. Besides aseptic loosening, periprosthetic femoral fracture is an important mode of failure in the long term following uncemented THA

Peri-prosthetic femoral fracture after total hip replacement (THR) is associated with a poor outcome and high mortality. However, little is known about its long-term incidence after uncemented THR. We retrospectively reviewed a consecutive series of 326 patients (354 hips) who had received a CLS Spotorno replacement with an uncemented, straight, collarless tapered titanium stem between January 1985 and December 1989. The mean follow-up was 17 years (15 to 20). The occurrence of peri-prosthetic femoral fracture during follow-up was noted. Kaplan-Meier survival analysis was used to estimate the cumulative incidence of fracture. At the last follow-up, 86 patients (89 hips) had died and eight patients (eight hips) had been lost to follow-up. A total of 14 fractures in 14 patients had occurred. In ten hips, the femoral component had to be revised and in four the fracture was treated by open reduction and internal fixation. The cumulative incidence of peri-prosthetic femoral fracture was 1.6% (95% confidence interval 0.7 to 3.8) at ten years and 4.5% (95% confidence interval 2.6 to 8.0) at 17 years after the primary THR. There was no association between the occurrence of fracture and gender or age at the time of the primary replacement. Our findings indicate that peri-prosthetic femoral fracture is a significant mode of failure in the long term after the insertion of an uncemented CLS Spotorno stem. Revision rates for this fracture rise in the second decade. Further research is required to investigate the risk factors involved in the occurrence of late peri-prosthetic femoral fracture after the implantation of any uncemented stem, and to assess possible methods of prevention

Aim: A ten-year review of uncemented hip arthroplasty using the Spotorno (CLS) stem, Morscher (Mathys) cup and a ceramic head in patients under the age of 60. Method: 113 hips implanted in 104 patients (mean age 50.5: range 19–60) between 1987 and 1995. Mean follow-up: 9.7 years. A postal questionnaire, based on the modiþed Harris Hip Score was followed by clinical and radiographic examination. Results: 3 patients had died and 18 (17%) could not be traced. Complications: sepsis 2%; aseptic loosening 5%; gross polyethylene wear 1%; fractured ceramic head 1%; periprosthetic fracture 1%. Pain was ñabsentñ or ñmildñ in 90%,and ñmoderateñ in 10%. 59.7% had a modiþed Harris Hip Score above 90, 35.8% between 70 and 90, and 4.5% less than 70 (mean 89.4%). According to Enghñs criteria, femoral stems had Ôingrowth conþrmedñ in 94%, suspected in 5% and þbrous encapsulation in 1%. None was predicted as unstable. Osteolysis was absent around 65.8% of stems, conþned to the neck in 14.8%, present proximally in 17.1% and distally in 2.3%. According to ARA criteria, acetabular þxation was Ôexcellentñ in 72.1%, Ôfairñ in 12.8% and Ôpoorñ in Osteolysis around the cup was Ôabsentñ or in Ôminimal in 91.8%, Ômoderateñ in 3.5% and Ôsevereñ in 4.7% Conclusions: We observed an association between acetabular polyethylene wear rates and radiographic evidence of osteolysis, which was greater around the rough-blasted stem than the hydroxyapatite-coated cup. Where osteolysis is present, the linear wear rate is consistently greater than 0.1mm/year, which may seem high but is comparable to other currently-used cement-less combinations.

Introduction: The treatment of “congenital hip disease” by total hip arthroplasty is now well established, but the indications for this type of surgery, the preoperative planning, the selection of the stem and the technique to be followed are still open to debate. Aim of the study: The purpose of this study is to analyse the long-term follow up after use of the cementless-system (CLS) femoral component designed by Spotorno in dysplastic or congenitally dislocated hips. Material and Methods: Our study includes 70 hips in 59 patients, 49 females and 10 males, 36 left hips and 34 right hips that treated with total hip arthroplasty from 1987 to 2000. The mean age of the patients was 48.5 years (range 34–74 years). Forty-one hips were congenitally dislocated and twenty-nine were severe dysplastic. Preoperative planning with CT and CAD-CAE system were used for selection of the stem. 11 patients had bilateral total hip arthroplasties with Spotorno CLS stem. Many different cups were used. Results: The mean follow up was 8.1 years (range 2–14 years). No patients were lost during the follow-up period. Patients were evaluated clinically with Merle d’ Aubigne and Postel hip score. There was a significant postoperative clinical improvement of the mean pain score by 3.7 points, of walking ability by 2.2 points and of motion by 2, 6 points. Thigh pain was not reported. There were no deep infections or mechanical loosening that required revision of the femoral component. Conclusions: Although, the femoral component Spotorno CLS is used to every kind of hip diseases, had excellent long-term clinical results in adults, with dysplasia or congenital hip dislocation. Spotorno CLS uncemented femoral component represents an attractive option for adults with “congenital hip disease”

INTRODUCTION: The treatment of “congenital hip disease” by total hip arthroplasty is now well established, but the indications for this type of surgery, the preoperative planning, the selection of the stem and the technique to be followed are still open to debate. AIM OF THE STUDY: The purpose of this study is to analyse the long-term follow up after use of the cementless-system (CLS) femoral component designed by Spotorno in dysplastic or congenitally dislocated hips. MATERIAL AND METHODS: Our study includes 70 hips in 59 patients, 49 females and 10 males, 36 left hips and 34 right hips that treated with total hip arthroplasty from 1987 to 2000. The mean age of the patients was 48.5 years (range 34–74 years). Forty-one hips were congenitally dislocated and twenty-nine were severe dysplastic. Preoperative planning with CT and CAD-CAE system were used for selection of the stem. 11 patients had bilateral total hip arthroplasties with Spotorno CLS stem. RESULTS: The mean follow up was 8.1 years (range 2–14 years). No patients were lost during the follow-up period. Patients were evaluated clinically with Merle d’ Aubigne and Postel hip score. There was a significant postoperative clinical improvement of the mean pain score by 3.7 points, of walking ability by 2.2 points and of motion by 2,6 points. Thigh pain was not reported. There were no deep infections or mechanical loosenings that required revision of the femoral component. CONCLUSIONS: Although, the femoral component Spotorno CLS is used to every kind of hip diseases, had excellent long-term clinical results in adults, with dysplasia or congenital hip dislocation. Spotorno CLS uncemented femoral component represents an attractive option for adults with “congenital hip disease”