Results of the cemented Exeter femoral component in patients under the age of 40 : an update at ten to 20 years' follow-up.

AIMS: We carried out a further study of the long-term results of the cemented Exeter femoral component in patients under the age of 40 with a mean follow-up of 13.6 years (10 to 20). PATIENTS AND METHODS: We reviewed our original cohort of 104 cemented Exeter stems in 78 consecutive patients with a mean age of 31 years (16 to 39). Only one patient was lost to radiological follow-up. RESULTS: A total of six patients (eight hips) had died for reasons unrelated to their surgery. There had been one further periprosthetic fracture from a fall and one fractured femoral stem. No revisions for aseptic loosening were undertaken during the whole study period. Overall, 11 hips had progressive radiolucent lines in one or more zones. The Kaplan Meier survival percentages at ten and 17 years were 97.1% (95% confidence interval (CI) 91.3 to 99.1) and 92.1% (95% CI 74.1 to 97.8) with revision for any reason as the endpoint, and 100% at both ten and 17 years with aseptic loosening (95% CI 83.8 to 100) as the endpoint. No additional hips were classified as radiologically loose. CONCLUSION: The Exeter femoral component continues to function satisfactorily in young patients for up to 17 years after surgery. Cite this article: Bone Joint J 2017;99-B:192-8.

Diagnostic criteria of traumatic central cord syndrome. Part 2: a questionnaire survey among spine specialists.

STUDY DESIGN: A questionnaire survey. OBJECTIVES: To evaluate the need for the introduction of quantitative diagnostic criteria for the traumatic central cord syndrome (TCCS). SETTING: An online questionnaire survey with participants from all over the world. METHODS: An invitation to participate in an eight-item online survey questionnaire was sent to surgeon members of AOSpine International. RESULTS: Out of 3340 invited professionals, 157 surgeons (5%) from 41 countries completed the survey. Whereas most of the respondents (75%) described greater impairment of the upper extremities than of the lower extremities in their own TCCS definitions, symptoms such as sensory deficit (39%) and bladder dysfunctions (24%) were reported less frequently. Initially, any difference in motor strength between the upper and lower extremities was considered most frequently (23%) as a 'disproportionate' difference in power. However, after presenting literature review findings, the majority of surgeons (61%) considered a proposed difference of at least 10 points of power (based on the Medical Research Council scale) in favor of the lower extremities as an acceptable cutoff criterion for a diagnosis of TCCS. Most of the participants (40%) felt that applying a single criterion to the diagnosis of TCCS is insufficient for research purposes. CONCLUSION: Various definitions of TCCS were used by physicians involved in the spinal trauma care. The authors consider a difference of at least 10 motor score points between upper and lower extremity power a clear diagnostic criterion. For clinical research purposes, this diagnostic criterion can be considered as a face valid addendum to the commonly applied TCCS definition as introduced by Schneider et al.

Diagnostic criteria of traumatic central cord syndrome. Part 1: a systematic review of clinical descriptors and scores.

STUDY DESIGN: Systematic review. BACKGROUND: The applied definition of traumatic central cord syndrome (TCCS) lacks specific quantified diagnostic criteria. OBJECTIVE: To review currently applied TCCS diagnostic criteria and quantitative data regarding the 'disproportionate weakness' between the upper and lower extremities described in original studies reporting on TCCS subjects. METHODS: A MEDLINE (1966 to 2008) literature search was conducted. The descriptors applied to define TCCS were extracted from all included articles. We included original studies that reported on the differences in motor score (based on the Medical Research Council scale) between the total upper extremity motor score (UEMS) and the total lower extremity motor score (LEMS), in a minimum of five TCCS patients at the time of hospital admission. The mean difference between the total UEMS and the total LEMS of the patients included in each study was calculated. Case reports were excluded. RESULTS: None of the identified studies on TCCS patients reported inclusion and/or exclusion criteria using a quantified difference between the UEMS and LEMS. Out of 30 retrieved studies, we identified seven different clinical descriptors that have been applied as TCCS diagnostic criteria. Nine studies reporting on a total of 312 TCCS patients were eligible for analysis. The mean total UEMS was 10.5 motor points lower than the mean total LEMS. CONCLUSIONS: There is no consensus on the diagnostic criteria for TCCS. Nevertheless, this review revealed an average of 10 motor points between the UEMS and LEMS as a possible TCCS diagnostic criterion. However, further discussion by an expert panel will be required to establish definitive diagnostic criteria.

Aneurysmal bone cyst: the role of cryosurgery as local adjuvant treatment.

BACKGROUND: Aneurysmal bone cysts (ABCs) are most often treated with intralesional surgery (curettage) and additional bone grafting. There is debate on whether or not to use adjuvant therapy to decrease the local recurrence rate. This study is done to assess the outcome of curettage and cryosurgery as a treatment of ABC. METHODS: We analyzed 80 consecutive cases of ABC treated with curettage and cryosurgery. Patients were followed minimal 24 months after surgery (average 55 months, range 24-122 months) with physical examination and radiographs. Functional outcome was evaluated using the musculoskeletal tumor society score (MSTS). RESULTS: The 80 patients were all treated with curettage and cryosurgery. Additional bone grafting was used in 73 patients, osteosynthesis in 12 and spondylodesis in 1 patient. Four local recurrences were found in this study, a recurrence rate of 5%. All local recurrences were treated successfully with curettage and cryosurgery again 7-33 months after the initial surgery. Postoperative one fracture, one wound infection, and three transient nerve palsy occurred. The average MSTS score was 29.2 at follow-up. CONCLUSIONS: The use of cryosurgery as adjuvant therapy results in a lower local recurrence rate when compared to other publications for the treatment of ABC and excellent functional results.

Acetabular revision with impacted morsellised cancellous bone grafting and a cemented acetabular component: a 20- to 25-year follow-up.

We present an update of the clinical and radiological results of 62 consecutive acetabular revisions using impacted morsellised cancellous bone grafts and a cemented acetabular component in 58 patients, at a mean follow-up of 22.2 years (20 to 25). The Kaplan-Meier survivorship for the acetabular component with revision for any reason as the endpoint was 75% at 20 years (95% confidence interval (CI) 62 to 88) when 16 hips were at risk. Excluding two revisions for septic loosening at three and six years, the survivorship at 20 years was 79% (95% CI 67 to 93). With further exclusions of one revision of a well-fixed acetabular component after 12 years during a femoral revision and two after 17 years for wear of the acetabular component, the survivorship for aseptic loosening was 87% at 20 years (95% CI 76 to 97). At the final review 14 of the 16 surviving hips had radiographs available. There was one additional case of radiological loosening and four acetabular reconstructions showed progressive radiolucent lines in one or two zones. Acetabular revision using impacted large morsellised bone chips (0.5 cm to 1 cm in diameter) and a cemented acetabular component remains a reliable technique for reconstruction, even when assessed at more than 20 years after surgery.

Survival of massive allografts in segmental oncological bone defect reconstructions.

Reconstructions of large segmental bone defects after resection of bone tumours with massive structural allografts have a high number of reported complications including fracture, infection and non-union. Our goal is to report the survival and complications of massive allografts in our patients. A total of 32 patients were evaluated for fracture, infection, non-union rate and survival of their massive allograft reconstructions. The average follow-up for this group was five years and three months. The total fracture rate was 13% with a total infection rate of 16%. We found a low union rate of 25%. The total survival of the allografts was 80.8% (+/- 18.7%) after five years. We found a five-year allograft survival of 80.8% which is comparable with other studies.

The medium-term results of the cemented Exeter femoral component in patients under 40 years of age.

We evaluated the outcome of 104 consecutive primary cemented Exeter femoral components in 78 patients (34 men, 44 women) under the age of 40 years who underwent total hip replacement between October 1993 and May 2004. The mean age at operation was 31 years (16 to 39). No hip was lost to follow-up, but three patients (four hips) died. None of the deaths were related to the surgery. At a mean follow-up of 6.2 years (2 to 13), three femoral components had been revised for septic loosening. Using Kaplan-Meier survival analysis, the seven-year survival of the component with revision for any reason as the endpoint was 95.8% (95% confidence interval 86.67 to 98.7). The seven-year survival with aseptic femoral loosening as the endpoint was 100% (95% confidence interval 100). The cemented Exeter femoral component in patients under the age of 40 shows promising medium-term results. As it is available in a wide range of sizes and offsets, we could address all types of anatomical variation in this series without the need for custom-made components.

Oncological and functional results of cryosurgical therapy of enchondromas and chondrosarcomas grade 1.

BACKGROUND AND OBJECTIVES: Cryosurgery using liquid nitrogen is used as adjuvant treatment after intralesional resection of bone tumours to induce cell death. It is applied to enlarge the oncological margins of resection and to reduce the local recurrence rate. The objective of this study is to analyze the oncological and functional results. METHODS: We studied the oncological and functional results of curettage and cryosurgery in 123 patients with 130 tumors. There were 75 enchondromas and 55 chondrosarcomas grade 1. The minimal follow-up period for all patients was 2 years (range 24-119 months). RESULTS: During follow-up one local recurrence of an active enchondroma and one local recurrence of an aggressive enchondroma occurred. They were treated with curettage and cryosurgery again. Both patients were disease-free at minimum of 3 years follow-up. No local recurrences after treatment of chondrosarcoma grade 1 were seen. Functional scores, according to the MSTS scoring system, showed an average score of 28 points (94%) at 2 years follow-up. Post-operative fractures were seen in 18 patients (14%). CONCLUSIONS: Curettage and cryosurgery for enchondroma and chondrosarcoma grade 1 has excellent oncological and functional results. The post-operative management has been adjusted to reduce the number of fractures.

Polyurethane scaffold formation via a combination of salt leaching and thermally induced phase separation.

Porous scaffolds have been made from two polyurethanes based on thermally induced phase separation of polymer dissolved in a DMSO/water mixture in combination with salt leaching. It is possible to obtain very porous foams with a very high interconnectivity. A major advantage of this method is that variables like porosity, pore size, and interconnectivity can be independently adjusted with the absence of toxic materials in the production process. The obtained compression moduli were between 200 kPa and 1 MPa with a variation in porosity between 76 and 84%. Currently the biological and medical aspects are under evaluation.

[Choice of hip prosthesis in patients younger than 50 years]. / Keuze van heupprothese voor patiënten jonger dan 50 jaar.

There is no agreement about the most ideal type of hip prosthesis to be used in patients younger than 50 years. The most commonly used hip prostheses in patients younger than 50 years are uncemented or resurfacing prostheses and to a lesser extent cemented prostheses. A good result of a hip prosthesis can be defined as follows: 10 years after surgery more than 90% of the prostheses should be still in situ during endpoint revision for any reason. No trials are available comparing cemented, uncemented or resurfacing hip prostheses. Studies are available of cemented hip prostheses in patients younger than 50 years that prove that more than 90% of the hips are still in situ after 50 years. There are no studies available of uncemented or resurfacing hip prostheses in younger patients that prove that after to years of follow-up 90% or more of the prostheses are still in situ. The Scandinavian hip registers show that the highest rate of prostheses still in situ after 10 years is achieved by cemented hip prostheses.

[Favourable long-term results from cemented total hip arthroplasty combined with acetabular bone impaction grafting in patients under the age of 50]. / Goede langetermijnresultaten van een gecementeerde totaleheupprothese in combinatie met een acetabulumreconstructie met geïmpacteerde botsnippers bij patiënten jonger dan 50 jaar.

OBJECTIVE: Determination of long-term results of hip replacements in patients who, at the time of operation, were under the age of 50. Procedures whereby an existing acetabulum defect was filled with bone chips that were impacted into a strong layer, after which a cemented total hip prosthesis was implanted. DESIGN: Descriptive. METHOD: Prospectively collected data from patients who were under the age of 50, and had undergone a hip replacement operation at our hospital between 1 July 1979 and 31 December 1987 were analysed. Data were collected up to 31 December 2002. The main outcome was time to revision. Survival was calculated by the Kaplan-Meier method. RESULTS: The study group consisted of 25 patients, 17 women and 8 men with 29 prosthetic hips. The average age at operation was 37.6 years (range: 20-49). Follow-up time was 15-23 years (median: 18.7 years). 1 patient (1 hip) was lost to follow-up. 3 patients (4 hips) died within 15 years after the operation; none of them had undergone revision. 4 revisions had been performed: I septic loosening (14 years p.o.) and 3 aseptic loosenings (6, 15, 20 years p.o.). The cumulative survival with the end-point 'revision for any reason' was 96% (95% CI: 88-100) at to years and 88% (95% CI: 74-100) at 20 years; after exclusion of the septic loosening the survival at 20 years was 92% (95% CI: 80-100). CONCLUSION: Hip replacement including a reconstruction technique for an acetabulum defect in patients under the age of 50 was regarded as successful if after 10 years, at least 90% of the prostheses were still in situ.

Meniscal replacement in dogs. Tissue regeneration in two different materials with similar properties.

In earlier studies, meniscal replacement with a porous polymer implant led to regeneration of neo-meniscal tissue. To evaluate the influence of the chemical properties on the tissue regeneration in the implant, in the present study, the meniscus in the dog's knee was replaced with either an aromatic 4,4-diphenylmethanediisocyanate based polyesterurethane implant (Estane) (n = 6) or with an aliphatic 1,4-butanediisocyanate based polyesterurethane implant (PCLPU) (n = 6). After 6 months, the knee joints were resected and the tissue behavior in the two different prostheses was evaluated microscopically. In both prostheses, a meniscus-like distribution of the tissue phenotype was found with collagen type I in the peripheral fibrous zones and collagen type II in the central, more cartilaginous zones. The compression-stress behavior of the implant-tissue construct remained in between the stiffness of the polymer material and that of the native meniscus. The PCLPU implant seemed to provoke less synovial tissue reaction. After meniscectomy solely, in 5 out of 6 cases, a meniscus-like regenerate was formed. Furthermore, the articular cartilage degeneration after placing a PCLPU implant did also not exceed the degeneration after the Estane implant or after meniscectomy. The differences between these two implants did not seem to influence the tissue regeneration in the implant. However, PCLPU seemed to evoke less tissue reaction and, therefore, is thought to be less or even nontoxic as compared with the Estane implant. Therefore, for studies in the future, the authors prefer the PCLPU prostheses for replacement of the meniscus.

Altered phase-transitions in tibialis anterior and medial gastrocnemius during walking after limbsaving surgery.

OBJECTIVE: In normal gait onset activity in tibialis anterior at end stance is closely linked to reduction in activity in medial gastrocnemius. Is a similar transition also present in patients undergoing limb-saving surgery? METHODS: Nineteen subjects after limb-saving surgery of the lower extremity and ten age-matched controls were compared. Patients walked on a treadmill at their preferred speed. Bipolar surface EMG activity was recorded from the tibialis anterior and the medial gastrocnemius. RESULTS: Patients showed asymmetry in gait. In controls a close tibialis anterior and medial gastrocnemius connection was seen. The close link between ipsilateral tibialis anterior and medial gastrocnemius was absent in patients. Instead, a link was found between tibialis anterior onset in the affected and medial gastrocnemius onset in the non-affected leg. CONCLUSIONS: This finding suggests that two control mechanisms can be seen: a contralateral connection between tibialis and gastrocnemius and a less important ipsilateral connection. This means that automated phase switching in patients does not rely primarily on ipsilateral mechanisms but that instead the onset of the ipsilateral swing is linked to the moment of load acceptance by the contralateral leg These results are strikingly similar to those obtained in simulated limping by normal subjects. SIGNIFICANCE: Patients after limbsaving surgery have a clinically significant problem that creates aberrant gait patterns. This study provides new information about linking of ankle dorsiflexors and plantarflexors, as well as reporting the uncoupling of this mechanism in these patients after major surgery.

Displacement of the medial meniscus within the passive motion characteristics of the human knee joint: an RSA study in human cadaver knees.

The objective of this study was to validate an in vitro human cadaver knee-joint model for the evaluation of the meniscal movement during knee-joint flexion. The question was whether our model showed comparable meniscal displacements to those found in earlier meniscal movement studies in vivo. Furthermore, we determined the influence of tibial torque on the meniscal displacement during knee-joint flexion. Three tantalum beads were inserted in the medial meniscus of six human-cadaver joints. The knee joints were placed and loaded in a loading apparatus, and the movements of the beads were determined by means of RSA during knee-joint flexion and extension with and without internal tibial (IT) and external tibial (ET) torque. During flexion without tibial torque, all menisci moved in posterior and lateral direction. The anterior horn showed significantly greater excursions than the posterior horn in both posterior and lateral direction. Internal tibial torque caused an anterior displacement of the pathway on the tibial plateau. External tibial torque caused a posterior displacement of the pathway. External tibial torque restricted the meniscal displacement during the first 30 degrees of knee-joint flexion. The displacements of the meniscus in this experiment were similar to the displacements described in the in vivo MRI studies. Furthermore, the application of tibial torque confirmed the relative immobility of the posterior horn of the meniscus. During external tibial torque, the posterior displacement of the pathway on the tibial plateau during the first 30 degrees of flexion might be restricted by the attached knee-joint capsule or the femoral condyle. This model revealed representative meniscal displacements during simple knee-joint flexion and also during the outer limits of passive knee-joint motion.

Chemotherapy affects the pattern of failure after shear loading of the proximal tibial growth plate.

INTRODUCTION: Tibial bones are shorter and less resistant to shear forces after treatment with doxorubicin, methotrexate, or cisplatin. We investigated the pattern of failure after shear loading of the proximal tibial growth plate in rats treated with these chemotherapeutic agents. MATERIALS AND METHODS: Male Wistar rats from the age of 4 weeks were given doxorubicin intravenously at 15 mg/m2 body surface area (BSA), methotrexate 60 mg/m2 BSA, or cisplatin 7.5 mg/m2 BSA. There was one nontreated control group fed ad libitum an d a diet control group for each drug-treated group. At the age of 13 weeks the tibial bones were dissected. The proximal growth plate was shear loaded to failure in the posteroanterior direction. The pattern of failure through the growth plate was examined. RESULTS: In rats fed ad libitum the failure pattern ran mainly through the transitional zone between proliferating and hypertrophic chondrocytes, but the pattern of failure showed considerable variability. The pattern in rats treated with methotrexate or cisplatin and that in their diet controls were comparable. In rats treated with doxorubicin the fracture ran mainly through the trabecular zone. CONCLUSIONS: Doxorubicin affects the pattern of failure after shear loading of the proximal tibial growth plate, but methotrexate and cisplatin do not. Special attention should be paid to epiphyseal injuries in children treated with doxorubicin.

Design, synthesis and properties of a degradable polyurethane scaffold for meniscus regeneration.

Longitudinal lesions in menisci are among the most frequent orthopedic problems of the knee. Repair by simple techniques is only limited to the vascular part of the meniscus. For repair of the avascular part of the meniscus a scaffold, which will assist the body in the formation of new meniscus cell tissue, might be applicable. In this study a biomedical segmented polyurethane with poly(epsilon-caprolactone) as soft segment and 1,4-butanediisocyanate and 1,4-butanediol as uniform hard segments has been synthesised. The material has a micro phase separated morphology and excellent mechanical properties. A porous scaffold was prepared via a combination of liquid-liquid phase separation and salt leaching. The foams prepared combined a very high interconnectivity and porosity with the desired compression modulus. After six months of implantation in the knees of beagles full ingrowth with cells was obtained and it was found that meniscus like tissue had been formed in the scaffold. Moreover, compression behaviour appeared to be comparable to native meniscus tissue.

Prosthetic replacement of the medial meniscus in cadaveric knees: does the prosthesis mimic the functional behavior of the native meniscus?

UNLABELLED: Meniscus replacement by a polymer meniscus prosthesis in dogs resulted in generation of new meniscal tissue. HYPOTHESIS: Optimal functioning of the prosthesis would involve realistic deformation and motion patterns of the prosthesis during knee joint motion. STUDY DESIGN: Controlled laboratory study. METHODS: The movements of the meniscus were determined during knee joint flexion and extension with and without internal and external tibial torque by means of roentgen stereophotogrammetric analysis. Subsequently, the meniscus in 6 human cadaveric knee joints was replaced by a meniscus prosthesis. RESULTS: All different parts of the meniscus showed a posterior displacement during knee joint flexion. The anterior horn was more mobile than the posterior horn. The prosthesis mimicked the movements of the meniscus. However, the excursions of the prosthesis on the tibial plateau were less. The knee joint laxity was not significantly higher after replacement with the meniscus prosthesis. CONCLUSIONS: The prosthesis approximated the behavior of the native meniscus. Improvement in both the gliding characteristics of the prosthetic material and the fixation of the prosthesis may improve the function. CLINICAL RELEVANCE: The meniscus prosthesis needs to be optimized to achieve a better initial function in the knee joint.

Acetabular revision with impacted morsellised cancellous bone grafting and a cemented cup. A 15- to 20-year follow-up.

This study presents the clinical and radiological results of 62 consecutive acetabular revisions in 58 patients, at a mean of 16.5 years follow-up (15 to 20). The Kaplan-Meier survivorship for the cup with end-point revisions for any reason, was 79% at 15 years (95% confidence interval (CI); 67 to 91). Excluding two revisions for septic loosening at three and six years, and one revision of a well-fixed cup after 12 years in the course of a femoral revision, the survivorship was 84% at 15 years (95% CI; 73 to 95). At review there were no additional cases of loosening, although seven acetabular reconstructions showed radiolucent lines in one or two zones. Acetabular revision using impacted large morsellised bone chips (0.7 cm to 1.0 cm) and a cemented cup, is a reliable technique of reconstruction, when assessed at more than 15 years.

Tissue engineering of the meniscus.

Meniscus lesions are among the most frequent injuries in orthopaedic practice and they will inevitably lead to degeneration of the knee articular cartilage. The fibro-cartilage-like tissue of the meniscus is notorious for its limited regenerative capacity. Tissue engineering could offer new treatment modalities for repair of meniscus tears and eventually will enable the replacement of a whole meniscus by a tissue-engineered construct. Many questions remain to be answered before the final goal, a tissue-engineered meniscus is available for clinical implementation. These questions are related to the selection of an optimal cell type, the source of the cells, the need to use growth factor(s) and the type of scaffold that can be used for stimulation of differentiation of cells into tissues with optimal phenotypes. Particularly in a loaded, highly complex environment of the knee, optimal mechanical properties of such a scaffold seem to be of utmost importance. With respect to cells, autologous meniscus cells seems the optimal cell source for tissue engineering of meniscus tissue, but their availability is limited. Therefore research should be stimulated to investigate the suitability of other cell sources for the creation of meniscus tissue. Bone marrow stroma cells could be useful since it is well known that they can differentiate into bone and cartilage cells. With respect to growth factors, TGF-beta could be a suitable growth factor to stimulate cells into a fibroblastic phenotype but the problems of TGF-beta introduced into a joint environment should then be solved. Polyurethane scaffolds with optimal mechanical properties and with optimal interconnective macro-porosity have been shown to facilitate ingrowth and differentiation of tissue into fibro-cartilage. However, even these materials cannot prevent cartilage degeneration in animal models. Surface modification and/or seeding of cells into the scaffolds before implantation may offer a solution for this problem in the future.This review focuses on a number of specific questions; what is the status of the development of procedures for lesion healing and how far are we from replacing the entire meniscus by a (tissue-engineered) prosthesis. Subquestions related to the type of scaffold used are: is the degree of tissue ingrowth and differentiation related to the initial mechanical properties and if so, what is the influence of those properties on the subsequent remodelling of the tissue into fibro-cartilage; what is the ideal pore geometry and what is the optimal degradation period to allow biological remodelling of the tissue in the scaffold. Finally, we will finish with our latest results of the effect of tear reconstruction and the insertion of prostheses on articular cartilage degradation.

The management of clear cell sarcoma.

Clear cell sarcoma is a rare soft tissue tumour, constituting approximately 1% of all soft tissue sarcomas. Prognosis is reported to be poor due to the great propensity to metastasise regionally and distantly. In this paper, we report the surgical experience of two university hospitals. Both disease-free and overall survival after resection of clear cell sarcoma in this limited study were excellent, which may be explained by relatively small tumour size in seven out of eight patients and adjuvant radiation treatment. The current treatment for clear cell sarcoma is wide local tumour excision, with adjuvant radiation therapy for resection margins of less than 1 mm.