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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 147 - 147
4 Apr 2023
Tohidnezhad M Kubo Y Gonzalez J Weiler M Pahlavani H Szymanski K Mirazaali M Pufe T Jahr H
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Nuclear factor erythroid 2–related factor 2 (Nrf2) is a crucial transcription factor to maintain cellular redox homeostasis, but is also affecting bone metabolism. As the association between Nrf2 and osteoporosis in elderly females is not fully elucidated, our aim was to shed light on the potential contribution of Nrf2 to the development of age-dependent osteoporosis using a mouse model.

Female wild-type (WT, n=18) and Nrf2-knockout (KO, n=12) mice were sacrificed at different ages (12 weeks=young mature adult, and 90 weeks=old), morphological cortical and trabecular properties of femoral bone analyzed by micro-computed tomography (µCT), and compared to histochemistry. Mechanical properties were derived from quasi-static compression tests and digital image correlation (DIC) used to analyze full-field strain distribution. Bone resorbing cells and aromatase expression by osteocytes were evaluated immunohistochemically and empty osteocyte lacunae counted in cortical bone. Wilcoxon rank sum test was used for data comparison and differences considered statistically significant at p<0.05.

When compared to old WT mice, old Nrf2-KO mice revealed a significantly reduced trabecular bone mineral density (BMD), cortical thickness (Ct.Th), cortical area (Ct.Ar), and cortical bone fraction (Ct.Ar/Tt.Ar). Surprisingly, these parameters were not different in skeletally mature young adult mice. Metaphyseal trabeculae were thin but present in all old WT mice, while no trabecular bone was detectable in 60% of old KO mice. Occurrence of empty osteocyte lacunae did not differ between both groups, but a significantly higher number of osteoclast-like cells and fewer aromatase-positive osteocytes were found in old KO mice. Furthermore, female Nrf2-KO mice showed an age-dependently reduced fracture resilience when compared to age-matched WT mice.

Our results confirmed lower bone quantity and quality as well as an increased number of bone resorbing cells in old female Nrf2-KO mice. Additionally, aromatase expression in osteocytes of old Nrf2-KO mice was compromised, which may indicate a chronic lack of estrogen in bones of old Nrf2-deficient mice. Thus, chronic Nrf2 loss seems to contribute to age-dependent progression of female osteoporosis.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 36 - 36
1 Feb 2017
Jones H Gonzalez J Doherty D Noble P
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Introduction

As the population continues to grow and age, the incidence of revision total knee replacement (RTKR) is expected to rise significantly. Modularity within revision total knee systems is common, and recognition of modular junctions as an important source adverse local tissue reaction (ALTR) has not yet been fully described in the literature. In both hips and knees, ALTR may be caused by wear debris from articulating surfaces, stress shielding, and other classic areas of focus, but now attention is shifting towards the role of corrosion products from modular junctions. In severe cases, junctions can become welded together creating significant hurdles in revisions and potentially altered biomechanics in vivo. In view of these issues, the present study was undertaken: (i) to examine the level of damage observed in modular junctions of total knee prostheses obtained at revision, (ii) to correlate the severity of surface damage to the design and composition of the mating components, and (iii) to associate patient demographics and comorbidities with the spectrum of corrosion and fretting seen in retrieved implants.

Methods

117 TKR components from 76 patients were examined after retrieval from revision procedures performed at a single institution. Patient demographics and clinical data were compiled. The retrievals consisted of 57 femoral components and 60 tibial components from a diverse range of manufacturers. The implants were disassembled manually, or in a mechanical testing machine if cold welded, and separated into groups based on mating material type. Modular junctions were then examined using stereomicroscopy (Wild) at magnifications of X6 to X31. Upon inspection, damage on the male component was graded using modified Goldberg scales for corrosion and fretting (Table 1). Factors associated with trunnions having damage scores of 3 or higher were evaluated using standard statistical procedures to determine the susceptibility for corrosion of each junction type and location.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 37 - 37
1 Feb 2017
Jones H Chun A Kim R Gonzalez J Noble P
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Introduction

Corrosion products from modular taper junctions of hip prostheses have been implicated in adverse local tissue reactions after THR. Numerous factors have been proposed as the root causes of this phenomenon, including implant design and materials, manufacturing variables, intraoperative assembly, and patient lifestyle. As significant taper damage only occurs in a few percent of cases of THR, we have addressed this complication using a “forensic” examination of retrieval specimens to gain insight into the factors initiating the cascade leading to irreversible damage of the modular interface. In this study we report the categorization of over 380 retrievals into groups having shared damage patterns, metallic composition, and interface surface geometries to isolate the genesis of mechanically-assisted corrosion and its relation to intraoperative assembly, manufacturing, and postoperative loading.

Methods

A total of 384 femoral components were examined after retrieval at revision THR. The implants were produced by a diverse range of manufacturers, 271 in CoCr, and 113 in TiAlV, with both smooth (253) and machined (131) tapers. Initially, the implants were sorted into groups based on composition and taper roughness. Each trunnion was then cleaned to remove organic deposits and examined by stereomicroscopy at X6-X31. After an initial pilot study, we developed a classification system consisting of 8 basic patterns of damage (Table 1). We then classified all 384 trunnions according to this 8-group system. The prevalence of each pattern was calculated on the basis of both composition and surface texture of the trunnion.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 94 - 94
1 Jan 2016
Osadebe U Brekke A Ismaily S Loya-Bodiford K Gonzalez J Stocks G Mathis KB Noble P
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Background

With the rising demand for primary total hip arthroplasty (THA), there has been an emphasis on reducing the revision burden and improving patient outcomes. Although studies have shown that primary THA effectively minimizes pain and restores normal hip function for activities of daily living, many younger patients want to participate in more demanding activities after their operation. The purpose of this study was to examine the relationship between age, gender and patient satisfaction after total hip arthroplasty.

Methods

With IRB approval, 2 groups of subjects were enrolled in this study: (i) 143 patients at an average of 25 months (range 10–69 months) post-primary THA, and (ii) 165 control subjects with no history of hip surgery or hip pathology. All subjects were assigned to one of four categories according to their age and gender: Group A: 40–60 year old males (31 THA; 42 Controls), Group B: 40–60 year old females (25 THA; 53 Controls), Group C: 60–80 year old males (35 THA; 25 Controls), and Group D: 60–80 year old females (36 THA; 23 Controls). Each patient completed a self-administered Hip Function Questionnaire (HFQ) which assessed each subject's satisfaction, expectations, symptoms and ability to perform a series of 94 exercise, recreational and daily living activities. These included participation in work-out activities, adventure and water sports, running and biking, and contact and team sports. Each participant was also asked their activity frequency, symptom prevalence and satisfaction with their hip in performing each activity.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 453 - 453
1 Sep 2009
Barrios C Riquelme O Burgos J Hevia E Gonzalez-Lopez J Correa C
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This work was aimed at study the role of paraspinal muscles on spinal tensegrity. Four different models of spinal tensegrity breakage with and without injury of the posterior spinal muscle were investigated.

Fifteen minipigs (mean age 6-week) underwent costotransversectomy (CTT) at 5 consecutive vertebral segments. In 4 animals ribs and transverse processes (T7–T11) were removed through a posterior midline approach with complete desinsertion of paraspinal muscles. In other 3 animals, CTT was performed by a posterolateral approach (T6–T10) without detachment of paraspinal muscles. Other 4 minipigs underwent rib resection (T7-T11) throughout a thoracoscopic approach avoiding damage of posterior spinal muscles. A final group of 4 animals, a complete detachment of the paraspinal muscles was performed from T7 to T11 without removing bony structures and leaving in deep surgical wax attached to the spinous and transverse processes to avoid reinsertion of the muscles after surgery. Anatomic specimens were radiologically and macroscopically studied just at sacrifice 5 months after surgery

All 4 animals operated on of CTT by midline posterior approach developed structural spinal deformity with curve convexity at the side of rib removal (mean Cobb angle 34,6°). Animals undergoing CTT by posterolateral approach without paraspinal muscle detachment did not develop any significant spinal deformity. Absence of spinal deformity was also found in those animals in which rib resection was performed by thoracoscopy without injury of the posterior spinal muscles. All 4 animals undergoing detachment of the paraspinal muscles without CTT and application of the surgical wax developed scoliotic curves (mean Cobb angle of 28°).

In conclusion, a new insight on the underlying pathogenic mechanisms of scoliotic curves is given by using this spinal tensegrity model. Isolated damage of the posterior muscle-ligamentous structures around the costotransverse joints breaking muscles spine tensegrity seems to be mandatory to induce scoliotic deformity. Rib removal alone appeared to have less scoliotic inductive implication. The finding questions previous knowledge on scoliosis etiopathogeny.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 143 - 143
1 Mar 2009
Rochwerger A Gonzalez J Demortière E Louzan D Ould-Ali D Rosca V Curvale .
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Introduction: The scarf osteotomy is a reliable technique in bunion surgery. A so-called « self stable technique» was developed in our department since 1992. We report the results of retrospective study including two groups of patients which had a scarf osteotomy. In the first group they had an internal fixation and in the second one an ‘selfstable technique’ with no device.

Material and methods: One hundred and seventy one patients operated for hallux valgus were reviewed for this study. There were 105 feet operated with the so called ‘self stable techniqu’, using modified saw cuts and 103 had the conventional technique with an internal fixation. All patients had a clinical and radiological pre- and postoperative examination. The result was assessed according to the AOFAS Score.

Results: The follow-up was on average 6.3 years (ranging from 2 to 13 years). The result was considered satisfactory globally in 74% of the cases, 76% in the « selfstable group and 72% in the conventional group. All items were significantly improved in both groups and the good results remained with time: improvement in shoe wear, pain, angular corrections. The hallux valgus angle decreased from 34° to 16°, there was no difference between both groups. The first intermetatarsal angle changed from 15° to 10. No significant difference was found in term on bone healing and complications between both groups.

Discussion: These results are comparable with those of the literature. The « selfstable technique » is significantly identical to the conventional one. The patients have the same rate of complications. The corrections that this osteotomy is able to offer are not altered by the change of fixation of the osteotomy.

Conclusion: This modified scarf osteotomy of the first metatarsal provides equivalent long-term results in our experience.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 245 - 245
1 Jul 2008
FARHAT I DEMORTIÈRE E GONZALEZ J ROCHWERGER A CURVALE G
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Purpose of the study: The efficacy of metatarsophalangeal joint (MPJ) fusion for the treatment of hallux rigidus has been well defined in the literature. There is however still some debate about the efficacy of conservative treatment, especially concerning the respective role for each of several different techniques.

Material and methods: This study reports the analysis of 113 patients treated for hallux rigidus with minimum one year follow-up. Mean age of this predominantly female population was 58 years. Fusion of the MPJ of the great toe was performed for 77% of patients and conservative treatment for 23%: isolated osteophytectomy (n=5), dorsal cheilectomy and shortening osteotomy of P1 (5 cm on average) with or without dorsal flexion for the others. The clinical outcome was assessed with the Groulier criteria.

Results: Overall outcome was satisfactory in 85% of the patients treated by MPJ fusion; MPJ pain resolved in 92%. There was however late healing or nonunion in 13% with no apparent clinical impact. Conservative treatment successfully relieved pain in 80% of patients who were able to wear ordinary shoes and had improved dorsal flexion of the MPJ.

Conclusion: The results of this study are helpful in determining the appropriate indications for surgery as a function of the clinical and radiological presentation of hallux rigidus.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 244 - 244
1 Jul 2008
GONZALEZ J DEMORTIÈRE E BUSSY E LIMOUZIN J BERTANI A DI SCHINO M
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Purpose of the study: Chronic foot compartment syndrome is a rather new notion illustrated by four cases reported in the international literature. We report a new case with bilateral involvement. The diagnosis was established by dynamic thallium scintigraphy and suggested that a less invasive management would be appropriate.

Case report: A 32-year-old male Foreign Legion recruit developed exercise-induced pain in the medial portion of the plantar aspect of both feet. The pain persisted for several months and resisted medical treatment. No medical or surgical event could be identified in the patient’s history. Pain developed systematically with exercise which had to be interrupted. It regressed progressively after interruption of exercise. The physical examination and podoscopy were not contributive. Laboratory tests, plain x-rays, MRI, and bone scintigraphy were normal. The diagnosis of chronic foot compartment syndrome was entertained. Dynamic thallium-201 scintigraphy was performed on both feet to compare the soft tissue images. Intense uptake was observed on the early images and late images of the plantar vault. These images, present on both feet, were considered compatible with chronic foot compartment syndrome. Positive diagnosis was confirmed with pressure measurements in the medial compartment. Fasciotomy was performed for the medial compartment. The patient was able to run normally at one month with complete regression of the symptoms. The patient was symptom free at two years.

Discussion: Compartment pressure measurements currently constitute the gold standard diagnostic approach. MRI, Doppler, spectroscopy, and scintigraphy have been proposed. For this functional disorder, which occurs only after exercise, we consider that compartment pressure measurement is overly invasive and painful. Furthermore, dynamic thallium-201 scintigraphy has been found to be as reliable as pressure measurements. Comparative studies would be required to determine the best evidence-based choice.

Conclusion: Chronic foot compartment syndrome is a rare entity observed in the active young subject. The medial compartment is always involved. Fasciotomy is effective treatment. Compartment pressure measurements remain the gold standard but dynamic scintigraphy would be a promising examination which merits evaluation.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_III | Pages 272 - 273
1 Mar 2004
Sarasquete J Celaya F Jordán M Gonzalez J Pulido M
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Aims: Analyze the long-term survival of cementless meniscal bearing total knee arthroplasty (TKA). Methods: Two hundred and thirty-two consecutive cementless primary meniscal bearing Low Contact Stress TKA were performed on 203 patients in our institution from November 1988 to June 1996. The diagnosis was osteoarthritis in 192 knees (83%) and rheumatoid arthritis in 40 cases (17%). Mean age at surgery was 66.5 years (range:16–90). Cruciate retaining prosthesis was implanted in 81% and a cruciate sacrificing prosthesis in 19%. Twenty patients died and ten patients (4,3%) were lost to follow-up. The remaining 202 knees (87%) had an average follow-up of 116.7 months (range:70–165). Survival analysis was done using as end point revision surgery or recommended revision. Results: Twenty-six TKAs (11.2%) required revision: infection (3), patelar failure (2), tibial/femoral loosening (2) and polyethylene failure (19). Age, gender, diagnosis and sacrificing cruciate ligaments were not related with prosthesis failure (p> 0.05). The Kaplan-Meier survival analysis showed a mean of 155 months (95%CI:150–159). The life table survival estimate at 10 years was 90.4% (85–95). The cumulative survival rate for patellar failure was 99% (98–100), for mechanical loosening 99% (98–100) and 91.3% (87–96) for polyethylene failure. The Log Rank Test was significant for poliethylene failure (p=0.0005). Conclusions: In our experience overall long-term survival of cementless meniscal bearing TKAwas acceptable. Mobile bearing knee prosthesis satisfactorily resolved problems related with patellar failure or tibial/femoral loosening. Polyethylene failure continues to be the main problem in long-term survival of knee prosthesis.