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Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 170 - 171
1 Mar 2006
Hawkins R Calder P Goodier D
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The stability of an external ring fixator using trans-osseous wires is determined by the number of wires per ring, their tension and their configuration. Ideally a crossing angle of 90° in the centre of the bone provides the greatest stability. This is however rarely possible due to the restrictions imposed by safe anatomical corridors. The Taylor Spatial Frame is a hexapod structure which relies on 6 connecting struts attached to fixed tabs on the ring; the Ilizarov system allows connecting rods to be placed in any available spaces. The aim of this study was to identify differences in wire placement using the TSF compared with the standard Ilizarov ring. Method: Cross-sectional anatomical diagrams of the tibia were taken from 3 levels. Lines representing wires were drawn crossing at the centre of the bone. The maximum crossing angles for an Ilizarov ring using safe anatomical corridors were calculated. A TSF ring was then superimposed on the image and angles recalculated taking into account impedance caused by the strut tabs. The angles were compared using a Students t-test taking p=0.05 as significant. Results: The average maximum crossing angle of the Ilizarov wires was 61° compared with 36° for the TSF. At all 3 levels the angles were found to be significantly different (p=0.002). Discussion: Limitations in the trans-osseous wire placement has implications for construct stability and therefore function. This may force the surgeon to make greater use of half pins, or more wires. We have shown significant differences in pin placement using the TSF which should be taken into consideration when using the system


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_9 | Pages 42 - 42
17 Apr 2023
Hayward S Miles A Keogh P Gheduzzi S
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Lower back pain (LBP) is a worldwide clinical problem and a prominent area for research. Numerous in vitro biomechanical studies on spine specimens have been undertaken, attempting to understand spinal response to loading and possible factors contributing to LBP. However, despite employing similar testing protocols, there are challenges in replicating in vivo conditions and significant variations in published results. The aim of this study was to use the University of Bath (UoB) spine simulator to perform tests to highlight the major limitations associated with six degree of freedom (DOF) dynamic spine testing.

A steel helical spring was used as a validation model and was potted in Wood's metal. Six porcine lumbar spinal motion segments were harvested and dissected to produce isolated spinal disc specimens. These were potted in Wood's metal, ensuring the midplane of the disc remained horizontal and then sprayed with 0.9% saline and wrapped in saline-soaked tissue and plastic wrap to prevent dehydration. A 400N axial preload was used for spinal specimens. Specimens were tested under the stiffness and flexibility protocols.

Tests were performed using the UoB custom 6-axis spine simulator with coordinate axes. Tests comprised five cycles with data acquired at 100Hz. Stiffness and flexibility matrices were evaluated from the last three motion cycles using the linear least squares method.

According to theory, inverted flexibility matrices should equal stiffness matrices. In the case of the spring, the matrices matched analytical solutions and inverted flexibility matrices were equivalent to stiffness matrices. Matrices from the spinal tests demonstrated some symmetry, with similarities between inverted flexibility- and stiffness matrices, though these were unequal overall. Matrix element values were significantly affected by displacements assumed to occur at disc centre.

Spring tests proved that for linear, elastic specimens, the spine simulator functioned as expected. However, multiple factors limit the confidence in spine test results. Centre of rotation, displacement assumptions and rigid body transformations are known to impact the results from spinal testing, and these should be addressed going forward to improve the replication of in vivo conditions.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_10 | Pages 26 - 26
1 Oct 2022
Vles G Bossen J Kloos J Debeer P Ghijselings S
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Aim

A septic revision of an artificial joint is routinely split up in a so-called dirty phase and a clean phase. The measures taken to initiate the start of the clean phase vary significantly between musculoskeletal infection centers. We performed simulations of one-step exchanges of infected THAs and sought to 1) determine the effect of different clean phase protocols on the sterile field, and 2) determine whether or not it is possible to re-implant the new prosthesis completely clean.

Method

Nine fresh frozen cadaveric hips were used and primary THA was undertaken via a direct anterior approach. Before implantation of the components varying amounts of fluorescent powder (GloGerm) were deposited, simulating bacterial infection. Second, a one-step exchange was performed via a posterolateral approach. After implant removal, debridement, and lavage, randomization determined which clean phase protocol was followed, i.e. no, some or full additional measures. Finally, the new prosthesis was re-implanted (fig. 1).

In order to determine the effect of different clean phase protocols on contamination of the sterile field standardized UV light-enhanced photographs were obtained of 1) the gloves, 2) the instrument table, 3) the drapes, and 4) the wound and these were ranked on cleanliness by a blind panel of hip surgeons.

In order to determine whether or not it is possible to re-implant the prosthesis completely clean, the implant was taken out again at the end of the one-step exchange and inspected for contamination under UV light.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_8 | Pages 22 - 22
1 May 2019
Romeo A
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Patient perceptions regarding the functional outcomes and return to sports after shoulder replacement are often pessimistic, with many patients presenting for shoulder replacement surgery after months or years of avoiding the procedure so they could continue to live the current life they have, despite the increasing pain and dysfunction. Less common, but becoming more frequent, patients present with expectations that they will be able to return to all activities including heavy resistance training, cross-fit, rock climbing, and other strenuous overhead sports. In the past, little information has been available regarding the activities of shoulder arthroplasty patients after surgery. Typically, the boundaries have been set by the surgeon, with many patients cautioned or even prohibited from overhead sports, weight training, or heavy work responsibilities. A typical set of guidelines may include no repetitive overhead sports, except for recreational swimming, and no lifting over 20 pounds. Golf, jogging, hiking and other activities are allowed.

The origin of these restricted guidelines and expectations is unknown, but many believe that since the results of shoulder replacements are less favorable in younger patients, it may be due to the overuse or abuse of the shoulder joint that is more typical at a younger age. Others have suggested that common sense prevails and that an artificial joint made of metal and plastic has a finite number of total movements and tolerance to resistance activities, and therefore keeping these activities at a minimum would extend the longevity of the artificial joint. None of these concepts are backed up by evidence-based literature, essentially reflecting the personal bias of the surgeons who care for patients with these problems. Despite all of the sophisticated research, scoring scales, outcome measures, and value-based metrics, the only outcome that really matters is whether the patient can return back to their normal way of life, at home, at work, during sport, or any activity that is important to them.

Recent studies of patients who have had joint replacement surgery have revealed that our patients who participated in sports and work activities before surgery have a strong predilection to returning to those activities after successful shoulder replacement. The most common sports that shoulder arthroplasty patients enjoy including golf, swimming, tennis, but may also include many other choices including fitness activities, rowing, skiing, basketball, and softball. As expected, the return to these sports is less for reverse shoulder arthroplasty patients vs. anatomic shoulder arthroplasty patients. In a systematic review, more than 90% of anatomic shoulder replacement patients returned to sport, while 75% of reverse shoulder arthroplasty patients returned to some sporting activity. This may reflect the constraints of the reverse prosthesis, or, quite possibly reflect the typically older age and more sedentary lifestyle of patients who are indicated for reverse shoulder arthroplasty. In addition, if the patient had a preoperative expectation of return to recreational and sports activities as part of their normal way of life, their final results demonstrated better overall outcomes.

Shoulder arthroplasty surgeons should be concerned about the outcomes desired by our patients, and the results that provide true value to their lives. We are now more aware of the activities that they are going to return to, whether we recommend restrictions or not.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_23 | Pages 22 - 22
1 May 2013
Balakumar B Madhuri V
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Purpose

The correction obtained in the coronal plane knee deformity using guided growth was assessed in children with sick physes (Height<1SD of the normal children) to define the limits of this technique in sick physis

Methods

We retrospectively assessed deformity correction following guided growth using 8 plates in children with coronal plane deformity and metabolically abnormal physis- renal rickets in 6 and bone dysplasias (multiple epiphyseal dyspasia, spondyloepiphyseal dysplasia, metaphyseal dysplasia, mesomelic dysplasia, chondrodysplasia punctata) in 10 children aged 2 to 14 years. Lateral distal femoral angle(LDFA) and medial proximal tibia(MPTA) angles were serially assessed after eight plate application as a day care procedure. We noted correction achieved rate of correction, complications and additional surgical procedures. Fischer's exact test and multiple regression analysis was done to assess the effect of modifiers.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_II | Pages 188 - 189
1 Apr 2005
Manunta A Zirattu. F Lisai P Fadda M Zirattu G
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Arthoscopic biopsy provides adequate tissue for most diagnostic requirements. Examination of endoarticular tissue can assist in the diagnosis of some joint infections; sometimes cultures of synovial tissue may be positive even when blood and synovial fluid cultures have been negative. In chronic infections such as tuberculosis and fungal disease, and characteristic synovial lesions, such as granuloma, it may be advised. Both gout and pseudo-gout can demonstrate tophus-like deposits in synovial tissue. Synovial biopsy can have a major role in the diagnosis of synthetic arthritis after ACL reconstruction with synthetic ligaments to identify a foreign body granulomatous reaction to particulate material implant or to verify the arthroplasty effect after loosening of a knee prosthesis.

There is a lack of association between arthroscopic findings and clinical laboratory and radiological features of arthritis. The general diagnosis of rheumatoid arthritis (RA) is usually based on characteristic clinical, radiological and serological manifestations. Synovial biopsy in RA is not normally required for diagnosis because the appearance is not specific, but it may provide important prognostic information. Synovial chondromatosis and pigmented villonodular synovitis are tumours of the synovial membrane that require biopsy for diagnosis. The biopsy of articular cartilage is useful to evaluate the capacity of chondrocytes to proliferate and to test the regeneration of cartilage after resurfacing by autologous chondrocytes implantation or other techniques. Histological confirmation could improve the prognosis of the knee during arthrofibrosis (percentage of elastic fibres), fibrosis of Hoffa disease and cyclop lesion. Another application is study of ligamentisation phenomena after anterior cruciate reconstruction and the presence in osteoarthritic knees with degenerative changes in posterior cruciate ligament.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_13 | Pages 8 - 8
1 Mar 2013
Hamilton D Gaston P Simpson A
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INTRODUCTION

This study investigates the relationship between direct measurement of outcome and patient report of that outcome via the OKS. The stability of this relationship over time following surgery is also assessed.

METHODS

183 TKA patients were assessed pre-operatively and at 6, 26 and 52 weeks post-op. Oxford Knee Score was obtained along with measures of pain intensity, knee flexion, lower limb power and timed functional assessment. Correlation of performance variables with the OKS was assessed, and regression analysis performed on those that formed significant associations. Significance was accepted at p = 0.05.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 211 - 211
1 May 2009
McGillion S Cannon L
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Ankle arthroscopy is generally performed through anterior portals and provides good access to the anterior aspect of the ankle joint. However, the structure of the talus and the anatomical confines of the ankle joint limit access to posterior structures via this approach.

Developments in the technique of posterior ankle arthroscopy have determined the appropriate site for portals with minimal risk of iatrogenic neurovascular injury. This facilitates treatment of conditions such as flexor hallucis longus (FHL) release, excision of os trigonum for posterior impingement, treatment of retro-calcaneal bursitis and treatment of ankle and subtalar joint pathology.

Posterior ankle arthroscopy is a relatively new technique and has recently been adopted by the senior author. This study was performed to explore the benefits and limitations of this procedure and to identify early post operative results.

We describe our experience of this technique in treating 9 patients with varied posterior ankle pathology. 2 patients had excision of os trigonum; 2 had FHL release; 1 had both excision of os trigonum and FHL release; 3 had curettage for posterior osteochondral defect (OCD) of the talus; and 1 had resection of Haglund’s deformity. The mean pre-operative AOFAS scores (Ankle-Hindfoot Scale) was 73 (range 47 to 85). The mean post operative AOFAS score at 3 months was 82 (range 75 to 87). 4 patients had recent surgery and await follow up. There were no complications. Two cases exposed the limitations of this procedure: Incomplete resection of (i) a Haglund’s deformity required conversion to an open excision and (ii) a posteromedial OCD lesion will require further anterior ankle arthroscopy due to inadequate exposure.

We conclude that for the experienced arthroscopic surgeon this is a safe technique that facilitates treatment of a variety of ankle and hindfoot problems that would otherwise require open procedures.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 273 - 273
1 May 2009
Bistolfi A D’Angelo F Turell M Bellare A
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Aims: In recent years, radiation crosslinking has become an important processing step in the manufacture of ultra-high molecular weight polyethylene (PE) components of joint replacement prostheses due to its associated high wear resistance. Gamma or electron beam radiation treatment is usually followed by a heating step, either complete melting or annealing of PE close to but below the melting temperature for a specific time duration. The heat treatment is performed to decrease free radical concentration within the crystalline lamellae in order to make PE more oxidation resistant.

In this study, we hypothesized that high pressure processing of PE would be advantageous if it is performed only after irradiation and quenching of free radicals and that it would be detrimental if it preceded irradiation. We used accelerated oxidation, mechanical tests and wear tests to show

Methods: Ram-extruded rod stock of GUR 1050 PE (Ticona, Bayport, TX) was purchased from MediTECH Medical Polymers (Fort Wayne, IN) and machined into cylinders to snugly fit into a custom-built high-pressure cell. A Carver hydraulic press was used to apply a pressure of 500MPa to PE specimens preheated to various temperatures, slow cooled to room temperature followed by pressure release. The PE cylinders and untreated control PE were subjected to 50kGy gamma radiation, which is a dose sufficient for a high degree of crosslinking in PE. A Parr bomb reactor filled with oxygen gas and operating at 5atm pressure and 70_C temperature was used to oxidize PE for a period of 14 days, according to ASTM standard F2003–02, and later characterized using Fourier Transform Infrared Spectroscopy (FTIR). A second batch of PE was first irradiated, melted and then subjected to high pressure processing. ASTM standard tensile tests were conducted to determine whether there was any increase in mechanical properties. Scanning electron microscopy (SEM) and differential scanning calorimeter (DSC) were used to characterize the lamellar morphology.

Results: The morphological characterization techniques, SEM and DSC, showed that high pressure processing increased the crystallinity as well as lamellar thickness regardless of whether the process was conducted prior to or after irradiation. FTIR showed that there was a monotonic increase in oxidation with lamellar thickness if the irradiation was carried out after high pressure processing. Several mechanical properties such as modulus and yield stress of PE increased with increase in crystallinity, which is desirable for applications where PE is subjected to high stresses.

Conclusions: High-pressure processing benefits the mechanical properties of crosslinked PE when it is conducted after irradiation and melting. However, if it conducted prior to irradiation and is not followed by thermal treatment, it can lead to more trapped free radical and excessive oxidation. Therefore, it is important to employ this processing method after irradiation so that it improves the mechanical properties of crosslinked PE.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 52 - 52
1 May 2016
Stiegel K Ismaily S Noble P
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Introduction

Patients who undergo hip resurfacing, total hip arthroplasty (THA), and total knee arthroplasty (TKA) are frequently assessed post-operatively using objective scoring indices. A small yet significant percentage of these patients report specific unfulfilled functions following surgery, indicating unmet expectations. The purpose of this study was to examine the types of functional deficits reported for each class of surgery, how frequently these limitations occur, and the demographic of patients who experience/report these limitations.

Methods

Four groups of subjects were enrolled in this study: (i) 111 hip resurfacing patients at an average of 14 months after resurfacing, (ii) 170 patients at an average of 16 months post-primary THA, (iii) 61 patients at an average of 12 months post-primary TKA, and (iv) 64 control subjects with no history of hip or knee surgery or pathology. Each participant completed a self-administered Hip Function Questionnaire, Knee Function Questionnaire, or Hip Resurfacing Questionnaire which assessed each subject's overall satisfaction and expectations following surgery. The questionnaires included numerical scores of post-operative function as well as an open-ended question which inquired “Is there anything your knee/hip keeps you from doing?”


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 97 - 97
1 Dec 2013
Kaneyama R Shiratsuchi H Oinuma K Miura Y Higashi H Tamaki T Jonishi K
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Introduction:

Total knee arthroplasty (TKA) should aim to adjust the component gap (CG) difference between extension and flexion. However, this difference cannot be measured without placement of a femoral component. The bone gap reportedly decreases in extension after component setting. In contrast, it may be possible to use the mean value of the CG difference in several patients to adjust femoral resection amount beforehand. The purpose of this study is to evaluate the technique of adjusting CG difference using the mean values with measured resection technique (MRT) in TKA.

Materials and methods:

The subjects were 222 knees (40 male knees, 182 female knees; mean age 70.4 years). To adjust the CG difference after estimation, the femoral posterior condylar pre-cut technique was used. Extension gap was created by usual bone resection; 4 mm of the femoral posterior condyle was pre-cut, and after all osteophytes and soft tissues had been treated, a pre-cut trial component (thickness of 8 mm for distal femur and 4 mm for posterior condyle without the anterior portion) was mounted, achieving the same condition as the setting of a femoral component in MRT (Fig. 1). When the posterior cruciate ligament (PCL) could be easily preserved by intraoperative gap assessments, the PCL was preserved (190 knees, 86%).


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 285 - 285
1 Jul 2008
NIZARD R LACHERE A RADMANESH O HANNOUCHE D SEDEL L
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Purpose of the study: Computer assisted surgery for total knee arthroplasty is widely used in Europe. The reliability of these systems appears to be very good with bone cuts within 3° of the planned mechanical axis. Nevertheless, the relationship between intraoperative measurements provided by the navigation system and the postoperative gonometry can be used to assess the quality of realignment. The purpose of this work was to determine this relationship.

Material and methods: Thirty-three knees operated on with the Navitrack® system were assessed. Two senior operaters performed all procedures. An Omnia® cemented prosthesis with an ultracongruent fixed plateau was used in all cases. Intraoperative measurements wer made with the definitive prosthesis after cement solidification without stress on the knee. Postoperative gonometry was undertaken when the intraoperative flexion had disappeared six weeks to six months after the operation. Gonometric measurements were made by an independent operator using a computerized system operating on digitalized x-rays. The gonometric protocol had been standardized previously and only the gonometric measurements in compliance with this protocol were retained for analysis. The difference between measurements was analyzed with the t test for paired variables. Search for correlations was also performed.

Results: On average the intraoperative deviation was 0.8±0.8° (3° valgus to 2.4° varus). The postoperative gonometry showed 1.7±1.1° (3.4° valgus to 4.3° varus). The mean difference between the intraoperative axis and the measured postoperative axis was significant (p< 0.0001). There was no significant correlation between intraoperative and postoperative measurements.

Discussion: Computer-assisted navigation systems have their limitations which should be measured. The present findings would demonstrate a significant difference of minimal amplitude between the intraoperative measurement and the postoperative gonometry. Although the clinical pertinence of this difference remains to be demonstrated, it must be kept in mind for safe use of these navigation systems.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 278 - 278
1 Jul 2008
CLAVERT P MILLETT P WARNER J KEMPF J
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Purpose of the study: Posterior glenoid erosio is a common finging in patients with degenerative joint disease of the shoulder. Anterior release is usually recommended, almost always with correction of the glenoid retroversion. There is no real consensus on the gravity of these posterior lesions nor on the appropriate attitude. The purpose of this study was to define the limitations of asymmetrical reaming during correction of excessive glenoid retroversion during total shoulder arthroplasty.

Material and methods: Five fresh cadaver shoulders were used. The size of the glenoid cavity and the humeral head were measured to select the optimal size for the glenoid implant. The scapula was embedded in resin. Posterior glenoid erosion was created by reaming to simulate wear producing retroversion greater than 15°. A control computed tomography (CT) was obtained to verify the lesion. The glenoid cavity was then prepared in the same manner as for prosthesis implantation, restoring neutral version to enable implantation of the prosthetic component of the size initially determined. A second CT was obtained to confirm the correction of the retroversion.

Results: The retroversion was corrected in all cases. At least one point of the implant penetrated the glenoid wall in all cases. In three cases, four points were outside the wall. In one case, reaming caused a fracture of the anterior glenoid rim. Finally, in one case, the size of the implant had to be reduced to avoid an oversized implant.

Discussion: The limitations for asymmetrical reaming to correct for posterior wear yet leave enough bone stock for implantation of a glenoid prosthesis are not defined. This study shows that asymmetrical reaming of the anterior rim of the glenoid cavity cannot satisfactorily correct for glenoid retroverson greater than 15° because of the frailness of the anterior wall and the risk the points will penetrate the rim. These complications compromise the primary stablity of the prosthesis and probably secondary short-term and mid-term stability.

Conclusion: If the glenoid retroversion is excessive (> 15°), it would be advisable to graft the posterior defect.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 613 - 613
1 Oct 2010
Stevens M Bulstra S Hoekstra T Van Den Akker-Scheek I Wagenmakers R
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Objective of the study is to determine to what extent patients experience more limitations 1–5 years after revision total hip arthroplasty (THA) compared to patients after primary THA, and if this is accompanied by a reduction in physical activity behavior. Five hundred and six patients were included: 372 primary and 134 revision THA. Questionnaires were used to measure limitations and physical activity. Linear regression analysis showed that patients after revision surgery report significantly more, clinically relevant limitations compared with primary THA patients, but did not show a significant difference in mean total minutes of physical activity per week. Physical activity behavior appeared to be similar for primary and revision THA patients. The results stress the importance of determining different aspects of recovery after THA.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 9 - 10
1 Mar 2006
Puloski S Leunig M Ganz R
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Background: Numerous radiographic indices have been described to help define the degree of acetabular deficiency in adult patients with developmental dysplasia. The lateral centre-edge angle (LCE) of Wiberg and the anterior centre-edge (ACE) angle of Lequesne are two of the commonly measured indices that are reported in the evaluation of procedures that are used to correct acetabular deformity. Unfortunately much of the reported literature that tries to define abnormal indices has been extrapolated from the evaluation of “normal” pelvi or those with osteoarthritis. The purpose of this study was to evaluate the application and limitations of the LCE and ACE angles in a group of patients with developmental dysplasia treated with periacetabular osteotomy.

Methods: 50 cases were randomly selected from a larger cohort of over 500 patients with acetabular dysplasia treated at our institution with periacetabular osteotomy. The preoperative and post osteotomy false profile and anteroposterior plain radiographs were reviewed. Cases were first grouped into one of three categories based on a general estimation of the location of acetabular deficiency as determined from the AP radiograph.

A number of radiographic indices were measured and compared including the VCE angle, LCE angle, and acetabular angles of Tönnis and Sharp. Variation in both the VCE and LCE angle was evaluated by measuring the index using two different reference points. This included (1) the traditional mark of the furthest point along the sclerotic density of the weight bearing zone and (2) an alternate point representing the furthest extent of lateral or anterior bony coverage. Additional sources of measurement error were determined. The relationships between the centre-edge angles and other radiographic indices were determined. An evaluation of the indices and correction on post osteotomy radiographs was also performed.

Results: Fifty cases in 45 patients were reviewed. There were 31 female and 19 males. The mean age was 30 years (range, 17–45). A general review of all preoperative AP radiographs revealed that all hips displayed some degree of lateral deficiency.

Nineteen of these cases displayed a “classic” lateral and anterior deficiency. However, 19 cases displayed a more uniform deficiency and 12 cases were in fact retroverted.

Evaluation of the radiographic indices revealed:

A mean VCE angle of 2.3 degrees (SD±12.7) and LCE angle of 3.4 degrees (SD±9.3). These were corrected to 25.8 degrees (SD±11.6) and 28.6 degrees (SD±8.7) following osteotomy.

The VCE and LCE angles did not appear to be correlated (r=0.35). This is contrary to previous studies evaluating non-dysplastic pelvi (Chosa et al., 1997). The LCE angle showed no significant correlation to other lateral coverage indices (Tönnis, Sharp).

No correlation was seen either in the post osteotomy values, or in the absolute degree of correction.

The alternate VCE (aVCE), using the most anterior aspect of the acetabular margin as the reference point was consistently larger (p< 0.001) with a mean difference of 27.1 degrees (SD±10.0). There was however a positive correlation between these two methods of measurements (r=0.77).

A similar variation was seen when comparing the LCE angle and the alternate LCE (aLCE). The mean difference between measurements was 7.3 degrees (SD±8.7)(p< 0.001).

The mean VCE in hips with primarily anterior and lateral deficiency (−6.7°±12.5) was significantly lower (p< 0.01) than those with uniform deficiency (5.1°±8.3) or those with retroverted acetabuli (8.9°±13.3)

Dysplastic hips with a decreased LCE angle but relatively normal Tönnis angle should be treated carefully as osteotomy may result in excessive angular correction in the coronal plane, thus creating a negative Tönnis angle. This can ultimately lead to problems with lateral and/or anterolateral impingement.

Potential sources of error in measurement that were identified include:

Deformity of the acetabulum and occasional abnormalities of the femoral head limit the ability to identify the center of the rotation necessary to measure the centre-edge angles. Subluxation of the femoral head also creates a degree of error. These difficulties were observed in over 20% of cases.

Alteration in pelvic tilt and rotation theoretically decreases the accuracy of measurement. Practically over 30% of radiographs were seen as less than ideal.

The absolute reference point for VCE and LCE angles as the end of the sclerotic line in the weight bearing area can be (1) difficult to define (2) does not always represent the most anterior or lateral extent of the acetabular margin. This discrepancy appears to increases in dysplastic hips. This has been suggested previously (Fabeck et al.,1999) and is now supported by our findings.

Conclusion: Centre-edge indices can be useful parameters in defining acetabular morphology. However, these parameters should not be used in isolation and the absolute values do little to define the overall location and degree of deficiency in hips with acetabular dysplasia. A number of significant sources of measurement error limit their accuracy especially in patients with hip dysplasia. Currently, it is our feeling that no single radiographic parameter fully defines the specific morphology in each individual case nor reflects the success of correction when treating patients with periacetabular osteotomy.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_4 | Pages 21 - 21
1 Jan 2013
Caporaso F Pulkovski N Sprott H Mannion A
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Background

Self-rated disability scores in patients with chronic LBP (cLBP) do not always relate well to performance in traditional physical tests (e.g. back strength, fatigability, etc.). Therefore tests using “functional activities” that challenge for example trunk mobility and movement speed have been suggested as alternative “objective” outcome measures. We examined the relationship between self-reported disability and a battery of such functional tests.

Methods

37 patients with cLBP took part (45±12y; 23f, 14m); 32 completed 9 weeks' physiotherapy. Before and after therapy, the patients completed the Roland Morris disability questionnaire (RM) and performed a battery of 8 simple tests (stair climb, prolonged flexion, stand to floor, lift test, sock test, roll-up test, pick-up test, fingertip-to-floor test).


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_23 | Pages 13 - 13
1 May 2013
Barker A Smitham P Scarsbrook C Calder P
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A statement of the purposes of the study

This study examined the stability of two different hexapod frames at increasing strut angles and the possible use of an additional strut to aid stability.

Introduction

Hexapod frames have certain advantages over standard circular frames, however disadvantages include a rattle and instability at some strut angles. This could be particularly important when larger diameter rings are used over a shorter distance resulting in lower ring strut angles such as in the femur.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_10 | Pages 19 - 19
1 Jun 2023
Donnan U O'Sullivan M McCombe D Coombs C Donnan L
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Introduction. The use of vascularised fibula grafts is an accepted method for reconstructing the distal femur following resection of malignant childhood tumours. Limitations relate to the mismatch of the cross-sectional area of the transplanted fibula graft and thel ocal bone, instability of the construct and union difficulties. We present midterm results of a unique staged technique—an immediate defect reconstruction using a double-barrel vascularised fibula graft set in in A-frame configuration and a subsequent intramedullary femoral lengthening. Materials & Methods. We retrospectively included 10 patients (mean age 10 y)with an osteosarcoma of the distal femur, who were treated ac-cording to the above-mentioned surgical technique. All patients were evaluated with regards to consolidation of the transplanted grafts, hypertrophy at the graft-host junctions, leg length discrepancies, lengthening indices, complications as well as functional outcome. Results. The mean defect size after tumour resection was 14.5 cm, the mean length of the harvested fibula graft 22 cm, resulting in a mean (acute) shortening of 4.7 cm (in 8 patients). Consolidation was achieved in all cases, 4 patients required supplementary bone grafting. Hypertrophy at the graft-host junctions was observed in78% of the evaluable junctions. In total 11 intramedullary lengthening procedures in 9 patients had been performed at the last follow up. The mean Muskuloskeletal Society Rating Scale(MSTS) score of the evaluable 9 patients was 85% (57% to 100%)with good or excellent results in 7 patients. Conclusions. A-frame vascularised fibula reconstructions showed encouraging results with respect to defect reconstruction, length as well as function and should therefore be considered a valuable option for reconstruction of the distal femur after osteosarcoma resection. The surgical implementation is demanding though, which is emphasized by the considerable high number of com-plications requiring surgical intervention, even though most were not serious


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_11 | Pages 26 - 26
7 Jun 2023
Hoskins Z Kumar G Gangadharan R
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Periprosthetic femoral fractures are increasingly seen in recent years, adding considerable burden to the National Health Service. These require complex revision or fixation and prolonged post-operative care, with significant morbidity with associated costs. The purpose of this study was to assess whether the size of femoral cement mantle is associated with periprosthetic femoral fractures (PPF). This retrospective study was carried out on a cohort of 49 patients (Fracture Group - FG) who previously had a revision procedure following a proximal PPF between 2010 and 2021. Inclusion criteria – all primary cemented total hip replacements (THR). Exclusion criteria – complex primary THR, any implant malposition that required early revision surgery or any pre-fracture stem loosening. The antero-posterior (AP) radiographs from this cohort of patients were assessed and compared to an age, sex, time since THR-matched control group of 49 patients without PPF (Control Group - CG). Distal cement mantle area (DCMA) was calculated on an AP radiograph of hip; the position of the femoral stem tip prior to fracture was also recorded: valgus, varus or central. Limitations: AP radiographs only. Statistical analyses were performed using Microsoft® Excel. Chi-square test demonstrated statistically significant difference in DCMA between FG and CG. DCMA of 700 to 900 mm² appeared to be protective when compared to DCMA of 0 to 300 mm². Also, a valgus position observed in 23% in FG Vs 4 % in CG increased the risk, with a smaller area of DCMA. This study demonstrates and recommends that a size of 700 – 900 mm² of the DCMA is protective against periprosthetic fractures, which are further influenced by the positioning of the distal stem tip. This could be due to the gradual decrease in the stiffness gradient from proximal to distal around the stem tip than steep changes, thereby decreasing possibility of a stress riser just distal to the cement mantle or restrictor. Further biomechanical research specific to this finding may be helpful to validate the observation, progressing to suggest a safe standardised surgical technique


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_9 | Pages 66 - 66
17 Apr 2023
Sharp V Scott C Hing C Masieri F
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Establishing disease biomarkers has been a long-sought after goal to improve Osteoarthritis (OA) diagnosis, prognosis, clinical and pharmaceutical interventions. Given the role of the synovium in contributing to OA, a meta-analysis was performed to determine significant synovial biomarkers in human OA tissue, compared to non-OA patients. Outcomes will direct future research on marker panels for OA disease modelling in vitro/in vivo, aiding clinical research into OA disease targets. A PRISMA compliant search of databases was performed to identify potential biomarker studies analysing human, OA, synovial samples compared to non-OA/healthy participants. The Risk of Bias In Non-Randomised Studies of Interventions (ROBINS-I) tool assessed methodological quality, with outcome analysed by Grading of Recommendations Assessment, Development and Evaluation (GRADE). Meta-analyses were conducted for individual biomarkers using fixed or random effect models, as appropriate. Where three or more studies included a specific biomarker, Forest Plot comparisons were generated. 3230 studies were screened, resulting in 34 studies encompassing 25 potential biomarkers (1581 OA patients and 695 controls). Significant outcomes were identified for thirteen comparisons. Eleven favoured OA (IL-6, IL-10, IL-13, IP-10, IL-8, CCL4, CCL5, PIICP, TIMP1, Leptin and VEGF), two favoured non-OA controls (BMP-2 and HA). Notably, PIICP showed the largest effect (SMD 6.11 [3.50, 8.72], p <0.00001, I. 2. 99%), and TIMP1 resulted critically important (0.95 [0.65, 1.25], p <0.00001, I. 2. 82%). Leptin and CCL4 showed lower effects (SMD 0.81 [0.33, 1.28], p =0.0009; 0.59 [0.32, 0.86], p <0.0001, respectively). Thirteen significant synovial biomarkers showed links with OA bioprocesses including collagen turnover, inflammatory mediators and ECM components. Limitations arose due to bias risk from incomplete or missing data, publication bias of inconclusive results, and confounding factors from patient criteria. These findings suggest markers of potential clinical viability for OA diagnosis and prognosis that could be correlated with specific disease stages