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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_18 | Pages 28 - 28
14 Nov 2024
Heumann M Jacob A Gueorguiev B Richards G Benneker L
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Introduction

Transosseous flexion-distraction injuries of the spine typically require surgical intervention by stabilizing the fractured vertebra during healing with a pedicle-screw-rod constructs. As healing is taking place the load shifts from the implant back to the spine. Monitoring the load-induced deflection of the rods over time would allow quantifiable postoperative assessment of healing progress without the need for radiation exposure or frequent hospital visits. This approach, previously demonstrated to be effective in assessing fracture healing in long bones and monitoring posterolateral spinal fusion in sheep, is now being investigated for its potential in evaluating lumbar vertebra transosseous fracture healing.

Method

Six human cadaveric spines were instrumented with pedicle-screws and rods spanning L3 vertebra. The spine was loaded in Flexion-Extension (FE), Lateral-Bending (LB) and Axial-Rotation (AR) with an intact L3 vertebra (representing a healed vertebra) and after transosseous disruption, creating an AO type B1 fracture. The implant load on the rod was measured using an implantable strain sensor (Monitor) on one rod and on the contralateral rod by a strain gauge to validate the Monitor's measurements. In parallel the range of motion (ROM) was assessed.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_1 | Pages 26 - 26
2 Jan 2024
Jacob A Heumann M Zderic I Varga P Caspar J Lauterborn S Haschtmann D Fekete T Gueorguiev B Loibl M
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Stand-alone anterior lumbar interbody fusion (ALIF) provides the opportunity to avoid supplemental posterior fixation. This may reduce morbidity and complication rate, which is of special interest in patients with reduced bone mineral density (BMD). This study aims to assess immediate biomechanical stability and radiographic outcome of a stand-alone ALIF device with integrated screws in specimens of low BMD.

Eight human cadaveric spines (L4-sacrum) were instrumented with SynFix-LR™ (DePuy Synthes) at L5/S1. Quantitative computed tomography was used to measure BMD of L5 in AMIRA. Threshold values proposed by the American Society of Radiology 80 and 120 mg CaHa/mL were used to differentiate between Osteoporosis, Osteopenia, and normal BMD. Segmental lordosis, anterior and posterior disc height were analysed on pre- and postoperative radiographs (Fig 1). Specimens were tested intact and following instrumentation using a flexibility protocol consisting of three loading cycles to ±7.5 Nm in flexion-extension, lateral bending, and axial rotation. The ranges of motion (ROM) of the index level were assessed using an optoelectronic system.

BMD ranged 58–181mg CaHA/mL. Comparison of pre- and postoperative radiographs revealed significant increase of L5/S1 segmental lordosis (mean 14.6°, SD 5.1, p < 0.001) and anterior disc height (mean 5.8mm, SD 1.8, p < 0.001), but not posterior disc height. ROM of 6 specimens was reduced compared to the intact state. Two specimens showed destructive failure in extension. Mean decrease was most distinct in axial rotation up to 83% followed by flexion-extension.

ALIF device with integrated screws at L5/S1 significantly increases segmental lordosis and anterior disc height without correlation to BMD. Primary stability in the immediate postoperative situation is mostly warranted in axial rotation. The risk of failure might be increased in extension for some patients with reduced lumbar BMD, therefore additional posterior stabilization could be considered.

For any figures or tables, please contact the authors directly.


The Bone & Joint Journal
Vol. 97-B, Issue 12 | Pages 1693 - 1697
1 Dec 2015
Keightley AJ Nawaz SZ Jacob JT Unnithan A Elliott DS Khaleel A

This study aimed to determine the long-term functional, clinical and radiological outcomes in patients with Schatzker IV to VI fractures of the tibial plateau treated with an Ilizarov frame. Clinical, functional and radiological assessment was carried out at a minimum of one year post-operatively. A cohort of 105 patients (62 men, 43 women) with a mean age of 49 years (15 to 87) and a mean follow-up of 7.8 years (1 to 19) were reviewed. There were 18 type IV, 10 type V and 77 type VI fractures. All fractures united with a mean time to union of 20.1 weeks (10.6 to 42.3). No patient developed a deep infection. The median range of movement (ROM) of the knee was 110o and the median Iowa score was 85.

Our study demonstrates good long-term functional outcome with no deep infection; spanning the knee had no detrimental effect on the ROM or functional outcome.

High-energy fractures of the tibial plateau may be treated effectively with a fine wire Ilizarov fixator.

Cite this article: Bone Joint J 2015;97-B:1693–7.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_5 | Pages 20 - 20
1 May 2015
Unnithan A Jacob J Khaleel A
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Background:

The aim of this study was to review the surgical complications and clinical outcomes of patients with Pilon fractures treated with Ilizarov frames.

Methods:

Data collected included surgical complications, grade of initial injury using the Ruedi-Allgower classification and quality of reduction according to the Teeny and Wiss criteria. Outcome scores were collected retrospectively using the Foot and Ankle Disability Index (FADI).


The Bone & Joint Journal
Vol. 97-B, Issue 4 | Pages 449 - 457
1 Apr 2015
Pulikottil-Jacob R Connock M Kandala N Mistry H Grove A Freeman K Costa M Sutcliffe P Clarke A

Many different designs of total hip arthroplasty (THA) with varying performance and cost are available. The identification of those which are the most cost-effective could allow significant cost-savings. We used an established Markov model to examine the cost effectiveness of five frequently used categories of THA which differed according to bearing surface and mode of fixation, using data from the National Joint Registry for England and Wales. Kaplan–Meier analyses of rates of revision for men and women were modelled with parametric distributions. Costs of devices were provided by the NHS Supply Chain and associated costs were taken from existing studies. Lifetime costs, lifetime quality-adjusted-life-years (QALYs) and the probability of a device being cost effective at a willingness to pay £20 000/QALY were included in the models.

The differences in QALYs between different categories of implant were extremely small (<  0.0039 QALYs for men or women over the patient’s lifetime) and differences in cost were also marginal (£2500 to £3000 in the same time period). As a result, the probability of any particular device being the most cost effective was very sensitive to small, plausible changes in quality of life estimates and cost.

Our results suggest that available evidence does not support recommending a particular device on cost effectiveness grounds alone. We would recommend that the choice of prosthesis should be determined by the rate of revision, local costs and the preferences of the surgeon and patient.

Cite this article: Bone Joint J 2015;97-B:449–57.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_13 | Pages 18 - 18
1 Mar 2013
Liddle A Borse V Skrzypiec D Timothy J Jacob J Persson C Engqvist H Kapur N Hall R
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Interbody fusion aims to treat painful disc disease by demobilising the spinal segment through the use of an interbody fusion device (IFD). Diminished contact area at the endplate interface raises the risk of device subsidence, particularly in osteoporosis patients. The aim of the study was to ascertain whether vertebral body (VB) cement augmentation would reduce IFD subsidence following dynamic loading. Twenty-four human two-vertebra motion segments (T6–T11) were implanted with an IFD and distributed into three groups; a control with no cement augmentation; a second with PMMA augmentation; and a third group with calcium phosphate (CP) cement augmentation. Dynamic cyclic compression was applied at 1Hz for 24 hours in a specimen specific manner. Subsidence magnitude was calculated from pre and post-test micro-CT scans. The inferior VB analysis showed significantly increased subsidence in the control group (5.0±3.7mm) over both PMMA (1.6±1.5mm, p=.034) and CP (1.0±1.1mm, p=.010) cohorts. Subsidence in the superior VB to the index level showed no significant differences (control 1.6±3.0mm, PMMA 2.1±1.5mm, CP 2.2±1.2mm, p=.811). In the control group, the majority of subsidence occurred in the lower VB with the upper VB displaying little or no subsidence, which reflects the weaker nature of the superior endplate. Subsidence was significantly reduced in the lower VB when both levels were reinforced regardless of cement type. Both PMMA and CP cement augmentation significantly affected IFD subsidence by increasing VB strength within the motion segment, indicating that this may be a useful method for widening indications for surgical interventions in osteoporotic patients.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXII | Pages 80 - 80
1 May 2012
Young J Sott A Robertson N Hendry J Jacob J
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Metatarsal fractures are extremely common injuries accounting for 10% of all fractures seen in our accident and emergency departments (3). The vast majority can be treated conservatively. There is no standardised treatment, but it is commahplace to immobilise the foot and ankle joint in a below-knee back-slab, full cast or functional brace for a period of up to 6 weeks, weight-bearing the patient as pain allows. This practice is time-consuming and expensive, not to mention debilitating, and carries a morbidity risk to the patient.

We describe a simple, effective and cheap treatment method for metatarsal fracture management using the functional forefoot-offloading shoe (FOS). This is clinically proven to offload pressure on the metatarsals and is commonly used in both elective forefoot surgery and in diabetic patients.

Between January and September 2009, we identified 57 patients attending our fracture clinic with new metatarsal fractures. 28 met our inclusion criteria.

All patients reported a significant improvement in their pain

At Injury – mean 8.21 out of 10 (range 4-10)

After FOS fitting - mean 2.92 out of 10 (range 0-6)

The forefoot-offloading shoe is an excellent alternative to plaster casting or functional boot immobilisation, offering high patient satisfaction, an excellent outcome and a considerable cost-saving to the hospital trust.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 540 - 540
1 Nov 2011
Bauer T Lortat-Jacob A Hardy P
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Purpose of the study: Different metatarsal osteotomies performed via a percutaneous approach can be used to correct hallux valgus. The purpose of this work was to analyse the clinical and radiographic results of percutaneous treatment of hallux valgus using a distal wedge osteotomy of the metatarsal.

Material and methods: This was a consecutive prospective series of 125 cases of hallux valgus treated by the same surgical technique, distal wedge osteotomy of the metatarsal without fixation. Percutaneous lateral arthrolysis and percutaneous varus correction of the first phalanx were associated. The AOFAS function score for the forefoot was determined preoperatively and at last follow-up. Time to normal shoe wearing and to resumption of occupational activities were also noted. Angle correction was determined on the anteroposterior weight-bearing image. All patients were reviewed at mean 20 months (range 12–40).

Results: The AOFAS forefoot function score was 46/100 preoperatively and 87/100 at last follow-up. Mean motion of the metatarsophalangeal joint was 95 preoperatively and 80 postoperatively. Mean metatarsophalangeal valgus was 30 preoperatively and 12 at last follow-up. The mean intermetatarsal angle improved from 13 to 8 and the orientation of the joint surface of the first metatarsal (DMAA) improved from 11 to 7. The metatarsophalangeal joint of the first ray was congruent in 45% of the feet preoperatively and in 88% postoperatively. Mean time to wearing normal shoes was seven weeks for the treatment of hallux valgus alone and three months for surgery of the first ray and lateral rays.

Discussion: Percutaneous treatment of mild to moderate hallux valgus by distal wedge osteotomy of the metatarsal enables good clinical and radiographic improvement. The surgical technique requires experience with percutaneous surgery of the forefoot to avoid the main complications: secondary displacement in elevates and excessive shortening of the first metatarsal. This technique restores metatarsophalangeal congruence of the first ray compared with Isham-Reverdin osteotomy.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 536 - 536
1 Nov 2011
Bauer T Lhotellier L Mamoudy P Lortat-Jacob A
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Purpose of the study: The purpose of this work was to analyse the results of infection in patients with joint prostheses implanted after septic arthritis, distinguishing evolving versus cured arthritis.

Material and methods: This was a retrospective series of 70 cases of septic arthritis (in 69 patients) including 7 patients with mycobacterial infections and 63 patients with ordinary germ infections. For the seven mycro-bacterial infections (five Mycobacterium tuberculosis and two Mycobacterium xenopi), the arthroplasty was implanted on evolving arthritis and in two on arthritis considered cured. For the 63 cases of common germs (70% staphylococcal infections), the septic arthritis was considered evolving in 36 and cured in 27. For half of the cases, the arthritis was blood-borne and localised in the knee. For cases considered evolving, the arthroplasty was generally a two-phase procedure (32/36 cases). Adapted antibiotics were associated for 93 days on average (45–180). For arthritis considered cured, the arthroplasty was implanted on average 53 months (range 6–700) after the infectious episode, generally in a one-phase procedure (22/27). Adapted antibiotics were associated for 80 days on average in seven patients because of positive intraoperative samples. One patient was lost to follow-up before two years and all others were reviewed with at least two years follow-up (mean 5 years, range 2–13 years).

Results: For the seven cases of mycobacterial arthritis, one patient was lost to follow-up, six had no signs of infection at mean 7 years follow-up. For the other cases, 89% of patients who had a prosthesis for evolving arthritis were considered as cured, 6% relapsed before 18 months and 6% presented a new infection with a different germ. For arthroplasty after assumed cured arthritis, 81% of patients were considered cured, 15% relapsed before 18 months and 4% presented a new infection with another germ.

Discussion: Arthroplasty is the treatment of choice for septic evolving septic arthritis, enabling cure in more than 80%, irrespective of the causal germ, and whether cure of the infection was apparently achieved or not.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 541 - 541
1 Oct 2010
Rethnam U Acharya A Jacob J Ramesh B Sinha A
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Background: Knee prosthesis design is being constantly altered in a bid to imitate kinematics of the normal knee. It is hoped that this will improve the wear characteristics and performance of the implant. The ‘Medial Pivot’ knee has a characteristic geometry and is expected to lower contact stresses on the tibial surface and ease rehabilitation while providing greater stability.

We conducted a study comparing the midterm outcome of the Medial Pivot knee (MP) to the Posterior Stabilised (PS) knee.

Materials and Methods: Over a 3 year period, 312 knee replacements were carried out of which 124 were MP and 188 were PS. 100 patients from each of the 2 groups were called for review. Demographic data, age at operation, time since surgery and ASA grading were noted. Postoperative knee function was assessed using the American Knee Society (AKS) and Oxford Knee (OK) scores and the scores were compared between the 2 groups. Individual functional parameters were also compared.

Results: 38 patients with 42 replaced knees in the MP group and 43 patients with 52 replaced knees in the PS group were reviewed. The 2 groups were comparable in terms of gender of patients and age at operation and were followed up to a mean 31 months. For the MP group the mean AKS knee assessment score was 77/100, AKS function score was 75/100 and OK Score was 23/60. For the PS group the corresponding values were 81/100, 77/100 and 22/60. The differences in scores between the groups were not statistically significant. Only active and passive knee extension was better following MP Arthroplasty than PS arthroplasty (p< 0.05). Although the mean flexion was better following the PS arthroplasty, this was not statistically significant.

Conclusion: Our study has shown that the midterm outcome for the Medial Pivot knee system did not show any distinct advantage over the Posterior Stabilised knee system in terms of knee pain & function.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 592 - 592
1 Oct 2010
Wiewiorski M Bilecen D Horisberger M Jacob L Kretzschmar M Leumann A Rasch H Valderrabano V
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Introduction: Pain is the key symptom of patients suffering of osteochondral lesion (OCL) of the ankle. However, its tissue origin and the pain inducing and modulating mechanisms remain controversial. Cartilage is aneural and unlikely causing pain. Contrary soft and bone tissue show rich nociceptive innervations. Routine radiographic imaging of OCL fails to visualize the pain inducing structure. Recent studies demonstrated the capability of planar scintigraphy and SPECT for localizing painful joints in degenerative joints conditions. However, a limited spatial resolution of bone scans compromises an accurate anatomical localization of an uptake. Single photon emission computed tomography – computed tomography (SPECT-CT) is a new hybrid imaging technique allowing perfect overlay of functional and anatomical images. In OCL, SPECT-CT identifies the exact location of an OCL and determines the spatial extent of pathological bone remodeling. We conducted a study to evaluate the correlation between pathological uptake within an OCL and pain experienced by patients.

Methods: 15 patients (7 female, 8 male; mean age 39, range 20–61 years) were assessed for unilateral OCL of the talus (13 joints) or distal tibia (2 joints). Radiological imaging of the foot and ankle consisted of plain radiographs, MRI and SPECT-CT. Clinical examination included range of motion (ROM), AOFAS Ankle-Hind-foot Scale, and pain status measured by the visual analogue scale (VAS). On completion of radiological and clinical assessment, patients were referred to the interventional radiology department for a diagnostic ankle injection. CTguided ankle joint injection with local anesthetics and iodine contrast medium was performed. Exact location of the deposit was documented.

VAS score was assessed immediately post-infiltration and compared to the pre-interventional VAS score. Pain relief was defined as a reduction of VAS score of more than 50% of the pre-intervention score immediately after infiltration.

The study was approved by the institutional review board and written informed patient consent was obtained. The study was carried out in accordance with the World Medical Association Declaration of Helsinki.

Results: All infiltrations were technically successful. Pre-interventional VAS score was 5.3 (range 2 - 10; SD 2.33). Post-interventional VAS score was 1.1 (range 2 – 4; SD 1.45). This difference was statistically significant (p < 0.01).

Discussion: The results of our study show a highly significant correlation between pain in OCL and pathological uptake seen on SPECT-CT, indicating bone as a major contributor to pain in this disease. Hybrid SPECT-CT technique is a new and powerful approach to diagnosis and staging of osteochondral lesions and provides important data for adequate treatment.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_II | Pages 275 - 275
1 May 2010
Wiewiorski M Kretzschmar M Rasch H Bilecen D Jacob A Valderrabano V
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Introduction: Determination of the origin of chronic foot pain in osteoarthritis (OA) is challenging since clinical examination of the foot faces a complex anatomy with several joints, osseous, and non-osseous structures contributing to the symptoms. Non-invasive imaging methods (Rx, CT, MRI) show a poor correlation with pain degree. Studies using functional imaging based on the detection of activated osteoblasts with 99mTc-Dicarboxypropandiphosphate (DPD) to indicate painful facet joints show promising results, but so far no evaluation for chronic OA pain conditions in foot joints has been conducted and the diagnostic potential was limited due to poor spatial resolution of the scintigraphic assessment.

Single Photon Emission Computed Tomography – Computed Tomography (SPECT-CT) combines metabolic information with an exact anatomical localization. We hypothesised that diagnostic infiltration with a local anaesthetic of a painful hindfoot or midfoot joint showing 99mTc-DPD-uptake in SPECT-CT, leads to a positive OA pain response.

Methods: 26 patients with chronic OA pain and radiological signs of OA in a hindfoot or midfoot joint (27 feet) were included. Plain radiography was performed to detect degenerative changes and to rule out pathologies different from OA. Pain status was measured by Visual Analogue Scale (VAS). AOFAS hindfoot/midfoot score and SF-36–score were documented. All patients received a 99mTc-DPD SPECT-CT (Symbia T2, Siemens). The localisation of 99mTc-DPD-uptake and consequently the site of infiltration were defined. The infiltration was performed with a local anaesthetic (bupivacaine) and iodine solution under CT-guidance with exact documentation of the contrast media deposit by CT. Pain status was assessed directly post-infiltration. Pain relief in responders was defined as reduction of VAS-score > 50% immediately after infiltration, partial response as reduction of < 50%.

Results: Infiltration was performed in 26 hindfoot joints and 5 midfoot as indicated by 99mTc-DPD-uptake in SPECT-CT. Subsequent CT control scans showing contrast media depot confirmed exact successful infiltration in all indicated joints. In 22 patients an immediate significant (p< 0.01) postinterventional pain reduction of VAS more than 50% was observed. Mean VAS before infiltration was 5.77 (range 2–10; SD 2.22) and 0.82 (range 0–4; SD 1.26) immediately after infiltration. Two patients showed a partial response and one patient showed no pain resolution after infiltration.

Conclusion: The results show a significant correlation of uptake and pain resolution after infiltration allowing precise identification of OA hindfoot joints as pain inducing foci. SPECT-CT offers good prediction of outcome after infiltration improving the localisation of the pain inducing joint, thus aiding in pre-operative planning.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 20 - 21
1 Mar 2010
Wiewiorski M Kretzschmar M Rasch H Bilecen D Jacob A Valderrabano V
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Purpose: Osteoarthritis (OA) is a common disease with increasing prevalence and rising socioeconomic burden. Of all symptoms accompanying OA, pain is the most disabling and frequent and the major reason why patients affected seek medical help. The determination of the origin of chronic foot OA pain is challenging since clinical examination of the foot faces a complex anatomy with several joints, osseous, and non-osseous structures contributing to the symptoms. For OA non-invasive imaging methods like plain radiograph, CT or MRI underestimate the degree of degenerative changes and show a poor correlation with pain degree. Studies using functional imaging based on the detection of activated osteoblasts with 99mTc-Dicarboxypropandiphosphate (DPD) to indicate painful facet joints in the lower spine show promising results, but so far no evaluation for chronic OA pain conditions in foot joints has been conducted and the diagnostic potential was limited due to poor spatial resolution of the scintigraphic assessment. Single Photon Emission Computed Tomography – Computed Tomography (SPECT-CT) is a new hybrid technique combining metabolic information with an exact anatomical localization. We hypothesised that diagnostic infiltration with a local anaesthetic of a painful hindfoot or midfoot joint showing 99mTc-DPD-uptake in SPECT-CT, leads to a positive OA pain response.

Method: 26 patients with chronic OA pain and radiological signs of OA in a hindfoot or midfoot joint (27 feet) were included. Plain radiography was performed to detect degenerative changes and to rule out pathologies different from OA. Pain status was measured by Visual Analogue Scale (VAS). AOFAS hindfoot/midfoot score and SF-36-score were documented.. All patients received a 99mTc-DPD SPECT-CT (Symbia T2, Siemens). The localisation of 99mTc-DPD-uptake and consequently the site of infiltration were defined. The infiltration was performed with a local anaesthetic (bupivacaine) and iodine solution under CT-guidance with exact documentation of the contrast media deposit by CT. Pain status was assessed directly post-infiltration. Pain relief in responders was defined as reduction of VAS-score > 50% immediately after infiltration, partial response as reduction of < 50%.

Results: Infiltration was performed in 26 hindfoot joints and 5 midfoot as indicated by 99mTc-DPD-uptake in SPECT-CT. Subsequent CT control scans showing contrast media depot confirmed exact successful infiltration in all indicated joints. In 22 patients an immediate significant (p< 0.01) postinterventional pain reduction of VAS more than 50% was observed. Mean VAS before infiltration was 5.77 (range 2–10; SD 2.22) and 0.82 (range 0–4; SD 1.26) immediately after infiltration. Two patients showed a partial response and one patient showed no pain resolution after infiltration.

Conclusion: The results show a significant correlation of uptake and pain resolution after infiltration allowing precise identification of OA hindfoot joints as pain inducing foci. Non-invasive SPECT-CT offers good prediction of outcome after infiltration improving the localisation of the pain inducing pathology, thus aiding in pre-operative planning and avoiding unnecessary interventions, as diagnostic infiltrations, with its possible risks and side effects.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 150 - 150
1 Mar 2010
Cooper H Jacob A Rodriguez J
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Proximally-coated non-cemented tapered femoral stems have demonstrated excellent long-term clinical results. However, there is sparse literature reporting the incidence of failure of osteointegration in patients with this stem design. The aim of this study is to report this incidence and identify factors which may increase its risk.

206 elective primary total hip arthroplasties were performed consecutively with a single stem design over a three-year period. All patients were evaluated clinically and radiographically. Radiographic parameters were analyzed for any potential risk factors that may predispose to failure of osteointegration.

Three of 206 hips failed to osteointegrate and subsequently underwent revision surgery, for an incidence of 1.5%. The average time to revision was 1.2 years. The presenting complaint was persistent pain and radiographs revealed a progressive linear lucency at the proximal implant-bone interface in all three patients. Each patient had been implanted with a large-sized stem that had achieved a diaphyseal fit radiographically. This cohort had a statistically lower canal-flare index (p < 0.05) when compared to the rest of the study group. At the time of surgery, all stems were found to be loose and were easily removed.

Failure of osteointegration in this type of stem is an uncommon but serious complication that may necessitate revision surgery. Risk factors predisposing to a failure to osteointegrate are a mismatch between the patient’s proximal femoral geometry and the stem, specifically a large stem in a Dorr type C femur, leading to a diaphyseal rather than a metaphyseal wedge.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 289 - 289
1 May 2009
Middleton C Pendegrass C Gordon D Jacob J Blunn G
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Introduction: Cell adhesion to titanium alloy implants is important in osseointegration [1,2] and attachment of the soft tissues to skin penetrating implants e.g. external fixator pins and Intraosseous Transcutaneous Amputation Prostheses [3,4]. Cell adhesion can be assessed using cell area data and immunolocalisation of focal contact proteins e.g. vinculin; however no method of assessing biophysical attachment is performed routinely. Cell adhesion can be enhanced with adhesion proteins including fibronectin (Fn)[5]. We have previously shown that covalently binding Fn to titanium also increases cell adhesion, and produces a more robust protein coating [6]. However the strength of adhesion of cells to this coating has not been measured. Our hypothesis was that biophysical cell adhesion measured using novel radial flow apparatus would correlate with cell area and focal contact data and that covalently bound fibronectin substrates would increase cell adhesion compared with adsorbed and uncoated controls.

Method: Dermal fibroblasts were cultured for 1, 4, and 24 hours on 30mm and 10mm diameter polished titanium alloy discs (n = 6). Cells on 30mm discs were calcein stained and subjected to shear stress in a submerged, media filled, custom-made radial flow apparatus at 37¬C at 1.66ml/s for 15s. Cells were fixed in 10% formal saline and photographs were taken using a tangential light source. Fluorescent microscopy was performed at 2mm intervals along two perpendicular diameters. Using image analysis, the central cell free zone was measured and radial distance and shear stress calculated. Cells on 10mm discs were fixed, permeablised and vinculin stained (mouse vinculin antibody (1:200) 2hrs; FITC mouse antibody (1:100)1hr). Images were analyzed with a Zeiss microscope linked to image analysis software and the number of focal contacts were counted per cell area. The medians of the radial flow data were compared with data for cell area and focal contact production at the same time points using Spearman¡s regression correlation. This method was subsequently used to compare cell adhesion at one hour with adsorbed and covalently bound Fn substrates (10¥ìg/disc).

Results/Discussion: The shear strength of cells increased between 4 and 24hrs (p=0.002) on polished untreated control substrates. Attachment values (dynes/cm2) were 84.90 (73.98–97.19), 96.30 (91.66–100.89), and 136.69 (134.68–140.30) for 1, 4 and 24 hours respectively. At 1hr, covalently bound Fn (509.90 dynes/cm2 (490.55–528.49) significantly increased cell adhesion compared with adsorbed Fn(434.45 dynes/cm2(385.25–465.62)) and control substrates(p=0.002). There was significant correlation between shear stress and focal contacts/cell (1.00(p< 0.01)) and focal contacts/cell area (0.900(p=0.037)), but not cell area (0.600(p=0.285)).

Conclusion: Radial flow measurement is a useful direct method to quantify cell adhesion to orthopaedic implants and correlates well with other methods of measurement. Covalently bound Fn significantly increases biophysical cell attachment compared with adsorbed and uncoated controls.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 464 - 465
1 Aug 2008
Jacob R
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The past ten years have brought plenty of research and technical innovations and also preliminary clinical success in cartilage repair. The common target of all methods utilised is to produce a sufficiently stable quality of cartilage repair or regenerate. However, yet today clinical, radiological and histological results analysing the different techniques are somewhat contradictory. The different lines of clinically applied and basic research have focused on:

1) Spontaneous natural filling of the defect with fibro-cartilage of variable solidity.

- Abrasion chondroplasty, drilling or microfracturing to allow for mobilisation of progenitor cells and mesenchymal stem cells from the cancellous bone into the defect and develop to a hyaline like cartilage.

- Stem cell treatment (in vivo or ex vivo theory of potential technique by which stem cells could be brought to a defect to create cartilage; so far no directly linked product available)

2) Transplantation of osteochondral auto grafts (Mosaicplasty, OATS, SDS, patellar graft) or allograft.

3a) Autologous chondrocyte transplantation and periosteal coverage (ACT) to cover bigger surfaces.

3b) Implantation of second and third generation ex vivo products and create less morbidity but without knowing whether the results are as long-lasting as for the originally described technique (chondrocytes cultured on membranes, MACI, in gels, implantation of a stable three-dimensional de novo cartilage disk or even engineered osteochondral grafts, AMIC: autologous membrane induced chondrogenesis).

A fair amount of today’s laboratory research is focusing on the culture of the patients own chondrocytes or his own stem cells.

Clinically, some methods can be applied in all indications regardless of size, localisation, depth of the lesion up to the age of fifty years and this is valid for lesions in the knee, the shoulder, the talus, the elbow etc. Other methods like AOCT should not be used for lesions over 2cm in diameter because of donor side morbidity. All methods claim to have an 85% outcome success rate. Regarding the histological content of the successful implants or the reformed cartilage, microfracturing produces a cartilage implant containing a fibrocartilage that looks similar to the hyaline like cartilage of ACI at two years. Mosaicplasty plugs provided great care is applied during insertion avoiding damage of the cylinders and cartilage death-a special instrumentation has been developed with ZIMMER, the Soft Delivery System, SDS to avoid force during impaction. They remain hyaline provided they are inserted without being prone or deep sunken and the surface convexity of the femoral condyle is restored and provided they are inserted tightly next to each other. There is agreement that this is more difficult in arthroscopic techniques. One agrees also that results are dependent on the alignment of the limb. If the compartment treated is overloaded, there is less chance for integration. Osteotomy has therefore a solid position in the armamentarium of the cartilage surgeon- up to 50% of our cases get an osteotomy as part of their treatment regardless of which technique is utilised.

As complications in autologous osteochondral grafting we may observe destruction of the hyaline cartilage cap, non integration and pseudarthrosis or fractures of the cylinders (of special risk are smokers), especially when grafts are not inserted tightly to each other and there is lack of stability with fluid leakage out of the cartilage caps. Rarely ossification of the cartilage is observed when a thin capped cylinder retrieved in the peripheral zone of the femoral trochlea is implanted in an area of thick cartilage as in the centre of the patella where the cartilage is 5 mm thick. Donor site pathology in mosaicplasty is an issue of concern mainly if more than six plugs are removed from the femoropatellar joint. This alone can create clinical symptoms.

Nicotine abuse, probably for all techniques decreases the rate of success of cartilage repair or regeneration and osteotomy healing.

Roughly 300 cases have been treated during the last 10 years. The results were reported in 2002.

As an alternate single surgery technique to microfracturing and mosaicplasty we adopted the “Autologous membrane induced chondrogenesis” (AMIC) technique proposed by Behrens that we find especially useful in OCD. In this relatively young technique we curette the defect and apply microfractures to the basis of the osseous defect. Then we gain cancellous bone from the tibial plateau and mix it with fibrin glue, of which 50% of the thrombin portion is replaced by the serum of the patient as a source of growth factor. This paste of bone and enriched fibrin glue is filled in the defect which is then covered by the porcine Chondrogide membrane (Geistlich) that is glued on and which we can as well suture to the defect. The AMIC technique in combination with microfractures can be utilised for the coverage of pure cartilage defects alone where the membrane is glued alone or fixed on the defect in combination with 5-0 resorbable sutures. In the first two weeks following surgery, after treatment is very defensive to avoid loss of the membrane. After two months of crutch walking with 15 kg of weight we observe a nice osseous integration of the graft and a covering layer that looks promising. After 4–6 months activity can be increased depending on the size of the defect. This is a young technique that we adopted in mid 2003 with 30 cases treated so far, therefore strict observation is required over the upcoming years regarding clinical results and durability and also the composition of this neocartilage. So far it seems to be an interesting alternative to Mosaicplasty since it combines principles of cell therapy with an artificial and instant biological containment that acts against the loss of cells thus acting as a internal bioreactor with the patients own growth factor support.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 212 - 212
1 Jul 2008
Tryfonidis M Jass GK Charalambous CP Jacob S Stanley D
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A significant number of patients return with persistent symptoms following surgical release of the posterior interosseous nerve for radial tunnel syndrome. The aim of this study was to attempt to explain this fact in anatomical terms by defining the anatomy of the posterior interosseous nerve and its branches in relation to the supinator muscle and arcade of Frohse. Using standard dissection tools 20 preserved cadaveric upper limbs were dissected. The radial nerve and all its branches within the radial tunnel were exposed and a digital calliper was used to measure distances. The bifurcation of the radial nerve to posterior interosseous nerve and superficial sensory branch occurred at a median distance of 4.35mm proximal to the elbow joint-line. The bifurcation was proximal to the joint-line in 11 cases, at the level of the joint-line in one case and distal in eight cases. There was a range of 0–5 branches to the supinator originating proximal to the entry point of the posterior interosseous nerve under the arcade of Frohse at a median distance of 10.27mm (medial branches) or 11.11mm (lateral branches) distal to the elbow join-line. These branches either passed under the arcade of Frohse or entered through the proximal edge of the superficial belly of the supinator. In 10 limbs there was a variable number of branches to the supinator originating under its superficial belly and in five limbs multiple perforating posterior interosseous nerve branches within the muscle were identified. This variation in anatomy we believe may explain the persistence of symptoms following surgical release of the posterior interosseous nerve for radial tunnel syndrome and suggests that careful exploration of all the nerve branches during surgical decompression should be routinely performed.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 274 - 274
1 Jul 2008
BAUER T HÀ NT RIMAREIX F LORTAT-JACOB A
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Purpose of the study: We present our experience with the distal-based sural flap for lower leg tissue defects.

Material and methods: This consecutive retrospective series included 45 flaps in 45 patients, 36 men and 9 women, mean age 50 years. The size and the cause of the tissue loss were described as were the patients’ history and risk factors. The distally-based fasciocutaneous sural flap was used in all cases. The postoperative period as well as the quality of the final cover were analyzed.

Results: At mean follow-up of 45 months, 43 of the 45 faciocutaneous flaps survived. Cover of initial tissue defect was complete in 41 cases and partial in two. Two flaps failed, leading to limb amputation. For the 25 patients with no risk factor, all flaps resulted in perfect tissue cover. In the 20 patients with risk factors, perfect cover was achieved for 16; only 10 of 20 flaps had an uneventful history with simple healing process; partial necrosis developed in eight flaps and two flaps failed.

Discussion: The Distally-based fasciocutaneous sural flap is a very reliable method offering many possibilities for covering lower limb tissue loss from the upper third of the leg to the ankle and hindfoot. The limitations are patient-related. There are thus many indications. For bone infections, one stage tissue cover can be achieved by integrating the flap as part of the overall treatment for the bone-related injury. This flap has an excellent vascular supply which increases the local concentration of systemic antibiotics. The distally-based sural flap can also be used successfully in traumatology.

Conclusion: The distally-based sural flap is reliable and relatively easy to perform. It provides excellent cover for most tissue losses situated on the lower half of the leg and ankle. The limitations are patient-related.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 264 - 264
1 Jul 2008
BAUER T LORTAT-JACOB A
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Purpose of the study: When infection occurs on solid bone tissue, the problems which arise concern filling the bony defect, achieving effective antibiotic therapy at the bone level, and correct cutaneous coverage. We present our experience in the management of 80 cases of bone infection on continuous bone tissue of the lower limb.

Material and methods: This was a retrospective series of 80 cases of bone infection on continuous bone in the lower limb in 77 patients, mean age 45 years. The infection had on average persisted for 13 years and the patients had undergone on average six operations at the infected site. Bone infection was a posttraumatic complication in three-quarters of the cases and localized in the tibia in half. The general and local status was assessed for each patient using the Cierny-Mader classification. All patients underwent surgery using the same operative protocol: resection, filling, bone cutaneous cover. We describe the different operative phases and the techniques employed. Patients free of clinical or biological signs of recurrent infection two years after hospital management were considered cured.

Results: All patients were reviewed, there were no patients lost to follow-up. At mean follow-up of four years, 81% of patients were considered cured. Recurrent infection was observed in 14% of cases, requiring revision on average two years after initial management. For 5% of the cases, the initial treatment failed and was followed by amputation. Poor general or local status and extensive diffuse osteitis were factors predictive of poor cure of the infection.

Discussion: We discuss the different causes and pathogenic mechanisms of osteitis on continuous bone. Surgical techniques are compared. Bone infection on continuous bone is an ideal indication for muscle or fas-ciocutaneous flaps for filling bone cavities and achieving cutaneous cover. The different modalities and duration of antibiotic therapy are discussed.

Conclusion: Bone infection on continuous bone is a specific often poorly individualized clinical situation. A specific surgical protocol is indicated to fill bony defects, and achieve cutaneous cover and thus definitive cure.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 58 - 59
1 Mar 2006
Buergi M Hilaire A Jacob Bereiter H
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Introduction: The non-cemented, extramedullary anchored Thrust Plate Prosthesis (TPP) was conceived as an implant for younger people with osteoarthrosis of the hip. The proximal part of the femur is loaded as physiologically as possible by transmitting the hip joint force directly to the cortex of the femoral neck, enabling the bone stock in the proximal femur to be preserved.

Materials and methods: We prospectively followed-up 102 hip replacements radiologically and clinically in 84 patients (63 men and 21 women) with a mean follow-up time of nine years (6–12 years). The mean age at operation was 54 years for the men and 47 years for the women.

Results: Four implants were revised: two because of an infection and two because of aseptic loosening. In 85 implants major contact was maintained between the thrust plate and bone, in ten implants partial contact prevailed, and in only three instances did the bone retract from the thrust plate so that a gap appeared. The average Harris hip score (HHS) increased from 51 points preoperatively to 96 points postoperatively.

Conclusions: Our long-term results with the TPP are similar to those for conventional prostheses of the stem type. The detected radiological changes normally take place in the first two years after implantation. After the prosthesis is osseointegrated aseptic loosening of the prosthesis is very unlikely. Bone remodelling underneath the thrust plate is in 85% of the cases as expected from the biomechanical principles. These long-term results confirm our encouraging medium-term observations. The TPP is a prosthesis of first choice when revision might be expected, as in the case of younger patients.