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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 19 - 19
10 May 2024
Earp J Hadlow S Walker C
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Introduction

This study aimed to assess the relationship between preparation times and operative procedures for elective orthopaedic surgery. A clearer understanding of these relationships may facilitate list organisation and thereby contribute to improved operating theatre efficiency.

Methods

Two years of elective orthopaedic theatre data was retrospectively analysed. The hospital medical information unit provided de- identified data for 2015 and 2016 elective orthopaedic cases, from which were selected seven categories of procedures with sufficient numbers to allow further analysis - primary hip and knee replacement, spinal surgery, shoulder surgery (excluding shoulder replacement), knee surgery, foot and ankle surgery (excluding ankle replacement), Dupuytrens surgery and general orthopaedic surgery. The data analysed included patient age, ASA grade, operation, operation time, and preparation time (calculated as the time from the start of the anaesthetic proceedings to the patient's admission to Recovery, with the operating time [skin incision to skin closure] subtracted). Statistical analysis of the data was undertaken.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_17 | Pages 12 - 12
1 Nov 2014
Ballal M Walker C Molloy A
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Introduction:

The insertion footprint of the different muscles tendon fascicles of the Achilles Tendon on the calcanium tuberosity has not been described before.

Method:

Twelve fresh frozen leg specimens were dissected to identify the different Achilles Tendon fascicles insertion footprint on the calcaneum in relation to their corresponding muscles. Further ten embalmed cadaveric leg specimens were examined to confirm an observation on the retrocalcaneal bursa.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_2 | Pages 28 - 28
1 Jan 2014
Bass E Sirikonda S Walker C
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Introduction:

Techniques devised for 1st MTPJ arthrodesis have been described since 1979 when Humbert et al published a ‘tongue and trough’ technique. Common contemporary techniques include fixation with single or crossed screws, or dorsal plates and these are suitable for a variety of indications. All three contemporary techniques have demonstrated a wide range of fusion rates. This study reports a comparison of non-union rates of the 1st metatarsophalangeal joint (MTPJ) with the current Memometal Anchorage™ dorsal plate system and the previous Hallu-fix™ and Charlotte™ systems.

Methods:

Between 01/2009 and 07/2012 174 consecutive 1st MTPJ fusions were performed for 153 patients (Mean age 62, range 42 to 83) by three surgeons at one University teaching hospital. 40 patients (23%) were male and 132 (77%) female. Patients without available radiographs were excluded from the study. 20 patients received Hallu-fix™ plates, 76 Charlotte™ plates and 76 Memometal Anchorage™. Radiographs of the feet were taken from four weeks postoperatively and reviewed for incomplete bone bridging and increased radiolucency around screws.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_30 | Pages 31 - 31
1 Aug 2013
Hopper G Wells J Leach W Rooney B Walker C Blyth M
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The Medial Patellofemoral Ligament (MPFL) is the main restraining force against lateral patellar displacement. It is often disrupted following patellar subluxation or dislocation. MPFL reconstruction is frequently performed when conservative management fails and the patient experiences recurrent patellar dislocation. Various MPFL reconstruction procedures have been described in the literature and reported outcomes are encouraging. This study analyses the radiographic outcomes following MPFL reconstruction.

From January 2006 to January 2011, 76 consecutive patients (80 knees) with patellar recurrent dislocation underwent medial patellofemoral ligament reconstruction in three large teaching hospitals. Mean follow-up was 31.8 months (range, 13–72). Semitendinosus and gracilis autografts were used for the reconstruction and all procedures were carried out by the senior authors (WL, BR, CW, MB).

Plain radiographs (Anteroposterior (AP), Lateral and Skyline) performed preoperatively and postoperatively were used to compare the sulcus angle, congruence angle, lateral patellofemoral angle, trochlear dysplasia (Dejour classification), trochlear boss height and patellar height (Caton-Deschamps ratio). Plain radiographs (Lateral) performed postoperatively were used to evaluate the femoral tunnel placement used for MPFL reconstruction.

The sulcus angle improved from 143.2° (122.9–157.7) to 139.3° (115.7–154.6) and the congruence angle improved from 26.7° (−17.5–82.6) to 0.26° (−35.3–7.8). The lateral patellofemoral angle was 7.99° (3.2–19.2) preoperatively and 9.02° (3.2–18.2) postoperatively. The Caton-Deschamps ratio was 1.2 (1.0–1.5) preoperatively and 1.0 (0.8–1.1) postoperatively. Using the Dejour classification of trochlear dysplasia, all preoperative radiographs were considered to be grade C or D and all postoperative radiographs were considered to be grade A or B. Trochlear boss height was 5.9mm (1.8–11.6) preoperatively and 4.7mm (1.6–6.9) postoperatively. 59% of the femoral tunnels were considered to be in a good position on postoperative radiographs.

This study displayed a significant improvement in postoperative radiographic parameters, demonstrating the importance of anatomic restoration when performing MPFL reconstruction.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_21 | Pages 31 - 31
1 Apr 2013
Nagy M Walker C Sirikonda S
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Introduction

There are a number of options available for surgical management of hallux rigidus. Ceramic implants of the first metatarsophalangeal joint (MTPJ) have been available for years; however there are no published long-term results existing.

Methods

We performed a retrospective review of all consecutive first MTPJ replacements carried out for later stage hallux rigidus using second generation MOJE ceramic implant with press-fit design. Two specialised foot and ankle surgeons performed these operations at a tertiary referral centre. Patient underwent regular follow ups including clinical review, functional scoring (AOFAS and FFI) and assessment of radiographs. Kaplan Meyer Survival analysis was performed.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLI | Pages 146 - 146
1 Sep 2012
Kempthorne J Kieser D Walker C Chin M Swain M
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When fixing a mid or distal periprosthetic femoral fracture with an existing hip replacement, creation of a stress-riser is a significant concern. Our aim was to identify the degree of overlap required to minimise the risk of future fracture between plate and stem.

Each fixation scenario was tested using 4th generation composite femoral Sawbones®. Each sawbone was implanted with a collarless polished cemented stem with polymethyl methacrylate bone cement and cement restrictor. 4.5mm broad Peri-loc™ plates were positioned at positions ½, 1 and 2 shaft diameters (SD) proximal and distal to the tip of the femoral stem. Uni-axial strain gauges (medial and lateral longitudinal gauges, anterior and posterior torsional gauges) measured microstrain at tip of the femoral stem with a standard load of 500N in axial, 3-point lateral and composite torsion/posterior loading using an Instron machine.

With axial loading fixation with 2SD proximal resulted in the least amount of strain, in both tension & compression, at the tip of the femoral stem. Fixation with 4 unicortical screws was significantly better than 2 alternating unicortical screws (mean microstrain difference 3.9 to 15.3, p<0.0001). With lateral 3-point loading fixation with 2SD proximal overlap and 2 alternating unicortical screws resulted in the least amount of strain, in both tension and compression, at the tip of the femoral stem (p<0.0001). With torsion & posterior displacement 2SD proximal fixation resulted in the least amount of rotational strain. There was no significant difference between 4 unicortical screws compared to 2 alternating unicortical screws (p>0.05 in 3 of 4 gauges).

Fixation of midshaft or distal femoral fractures with a well-fixed total hip arthroplasty should have at least 2 shaft diameters of proximal overlap with a 4.5mm broad plate. It is not clear if 4 unicortical screws or 2 alternating screws are optimal.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 358 - 358
1 Sep 2012
Gulati A Walker C Bhatia M
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Introduction

Venous thromboembolism (VTE) is a significant cause of patient morbidity and mortality, the risk of which increases in orthopaedic patients with lower limb immobilisation. This incidence should in theory reduce if the patients are ambulatory early in the treatment phase. The aim of this study was, therefore, to identify a difference in the incidence of symptomatic VTE by treating acute Achilles tendon rupture patients with conventional non-weight bearing plaster versus functional weight bearing mobilisation.

Methodology

The notes of 91 consecutive patients with acute Achilles tendon rupture were retrospectively reviewed and prospectively followed. The patients' demographics, treatment modality (non-weight bearing plaster versus weight bearing boot), and the type of plaster immobilisation was compared to assess whether they affect the incidence of clinical VTE. The predisposing risk factors were also analysed between the treatment groups.

Out of 91 patients, 50 patients with acute Achilles tendon rupture were treated conservatively in a conventional non-weight bearing immobilisation cast. From these 50 patients, 3 then underwent surgery and were therefore excluded from the results. On the other hand, 41 patients were treated with functional weight bearing mobilisation (Vacupad). Patients who did have a symptomatic thromboembolic event also had an ultrasound scan to confirm a deep vein thrombosis of the lower limb or a CT-scan to confirm pulmonary embolism.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 583 - 583
1 Sep 2012
Walker C Gulati A Bhatia M
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Introduction/Aim

Thromboembolism is a significant cause of patient morbidity and mortality, the risk of which increases in orthopaedic patients with lower limb immobilisation. It was therefore, our aim to identify a difference in symptomatic thromboembolism by treating acute Achilles tendon rupture patients with conventional non-weight bearing plaster versus functional weight bearing mobilisation.

Methodology

The notes of 91 consecutive patients with acute Achilles tendon rupture were reviewed. The patients demographics, treatment modality (non-weight bearing plaster versus weight bearing boot), and predisposing risk factors were analysed. From the 91 patients, 50 patients with acute Achilles tendon rupture were treated conservatively in a non-weight bearing immobilisation cast. From these 50 patients, 3 then underwent surgery and were therefore excluded from the results. 41 patients were treated with functional weight bearing mobilisation. Patients who did have a symptomatic thromboembolic event had an ultrasound scan to confirm a deep vein thrombosis of the lower limb, or a CT-scan to confirm pulmonary embolism.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLI | Pages 41 - 41
1 Sep 2012
Richmond B Munro J Walker C Hadlow S Lynskey T
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Proximal tibial bone mineral density (BMD) has been shown to decrease following Total Knee Arthroplasty (TKA) by both dual-energy x-ray absorbtiometry (DEXA) and quantitative computed tomography (qCT)-assisted osteodensitometry. Little is known about changes in BMD following unicompartmental knee arthroplasty (UKA). Additionally, there are proposed differences in stress transmission between cemented metal and polyethylene (PE) components. We proposed two hypotheses. First, that proximal tibial BMD decreases following UKA. Second, that BMD loss would be greater below metal tibial components.

We performed a prospective clinical trial of 50 consecutive UKAs in 49 patients performed by two surgeons at one institution. There were 25 mobile bearing Oxford and 25 fixed bearing Accuris arthroplasties, all were medial. BMD was assessed with qCT-assisted osteodensitometry scans prior to discharge and then at 1 and 2 years post surgery. Each CT slice was divided into medial and lateral halves and cortical and cancellous bone was analysed separately. The six 2mm slices immediately beneath the tibial implant were analysed using previously validated software to create a three-dimensional assessment of BMD. The lateral half was used as a control.

There were a total of 30 females (60%), with an average age of 70 (49–84). One patient was lost to follow-up and another was unable to be analysed due to failure requiring revision before follow-up was complete. Preliminary results showed no significant change in BMD at either 1 or 2 years follow-up. There was no difference in BMD change between the mobile and fixed bearing prostheses, between the medial and lateral halves nor between cortical and cancellous bone. Final results will be presented at the AONZOA conference.

This trial shows that UKA does not result in significant change to BMD at 2 years. The preservation of BMD may indicate that UKA is better at maintaining physiologic stress transfer than a TKA, which has been shown to be associated with a reduction in BMD.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLI | Pages 38 - 38
1 Sep 2012
Misur P Strick N Puna R Walker C
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There has recently been a proliferation of image-based knee arthroplasty systems which utilize pre-operative radiological analysis of a patient's anatomy to identify the bone cuts required to correct their mechanical alignment. The aim of this was to assess the accuracy of one such system (Visionaire™, Smith and Nephew Inc.©)

Eleven cadavers were imaged using the Smith and Nephew Visionaire® MRI protocol to enable the production of cutting blocks individualized to the various specimens. These cutting blocks were then used to perform knee replacements on all cadavers. Post-operatively the validated Perth CT protocol was used to assess the position and rotational profile of each implant. These measurements were then compared to the pre-operative plan in order to assess the accuracy of implant placement.

Relative to the pre-operative target parameters, the femoral components were aligned in a mean 0.048° valgus (95% CI – 0.36° to 1.32°) with 1.8° extension (95% CI −0.1° to 4.5°) and externally rotated by a mean 0.66° (95% CI 1.08° internal rotation to 2.4° external rotation.) The tibial components were in a mean 0.29° of varus (95% CI – 0.68° to 1.27°) with a posterior tibial slope of 90.5° (95% CI 89.6° to 92.6°) and internally rotated by a mean 1.7° (range 10.1° internal rotation to 1.1° external rotation.)

The findings of our study suggest that the Visionaire system can produce accurate coronal implant alignment. The saggital and rotational alignment was not as reliable although these parameters may have been more prone to adverse influence by the limitations of the cadaveric model. Patient-matched knee arthroplasty technology offers significant potential benefits to both patient and surgeon and warrants further clinical investigation.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXVIII | Pages 24 - 24
1 Jun 2012
Betts H Rowland D Murnaghan C Walker C Huntley J
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During the cold snap in the West of Scotland 20 December 2009 to 10 January 2010 there was a cluster of uncommon lower limb injuries in children from sledging accidents. These cases are presented as a series.

This retrospective descriptive study details acute orthopaedic admissions for the period of the cold snap. The case-notes for all admissions were reviewed for diagnosis, mechanism of injury.

Five (ex 20 ie 1/4) trauma admissions involved sledging: (1) combined avulsion of anterior and posterior cruciate ligaments left knee (2) Lisfranc injury, (3) distal femoral fracture, (4) distal tibial plafond fracture, (5) pelvis, patella also forearm and facial fractures. These cases are analysed in more detail

Sledging injuries comprise a substantial portion of workload and morbidity. In children, there is a propensity for lower limb and higher energy trauma. Tertiary referrals and non-standard trauma equipment may be required.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXII | Pages 72 - 72
1 May 2012
Hadi M Walker C Sheriff R Attar F Attar G
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Background & aim

There have been many operations described for the treatment of hallux valgus deformities and b ette done separately with variable success rates. Our aim is to radiologically assess the outcome following simultaneous osteotomies to the 1st and 5th metatarsals in symptomatic patients with splay foot. To our knowledge, this procedure has not been described in the literature yet.

Materials & method

9 symptomatic patients (12 feet) were included in the study. The pre-operative and post-operative X-rays were assessed and the hallux valgus angles, 1st and 2nd intermetatarsal angles, distal metatarsal articular angles (DMAA), 4th and 5th intermetatarsal angles, maximum widths of the 1st and 5th metatarsal heads and the maximum distance between 1st and 5th metatarsals were calculated. The improvement in the angles and distances post-operatively were then assessed for statistical significance using Non-parametric paired T tests.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVIII | Pages 31 - 31
1 May 2012
Findlay C Jameson S Marshall S Walker B Walker C Meek R Nicol A
Full Access

Background

Following an anterior cruciate ligament (ACL) injury, the affected knee is known to experience bone loss and is at significant risk of becoming osteoporotic. Surgical reconstruction is performed to attempt to restore the function of the knee and theoretically restore this bone density loss. Cross-sectional analysis of the proximal tibia using peripheral quantitative computed tomography (pQCT) enables localised analysis of bone mineral density (BMD) changes. The aim of this study was to establish the pattern of bone density changes in the tibia pre- and post- ACL reconstruction using pQCT image analysis.

Methods

Eight patients who underwent ACL reconstruction were included. A cross sectional analysis of the proximal tibia was performed using a pQCT scanner pre-operatively and one to two years post-operatively on both the injured and contralateral (control) knee. The proximal two and three percent slices [S2 and S3] along the tibia were acquired. These were exported to Matlab(tm) and automated segmentation was performed to remove the tibia from its surrounding structures. Cross correlation was applied to co-register pairs of images and patterns of change in BMD were mapped using a t-test (p<0.05). Connected components of pixels with significant change in BMD were created and used to assess the impact of ACL injury & reconstruction on the proximal tibial BMD.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXII | Pages 47 - 47
1 May 2012
Walker C Aashish G Bhatia M
Full Access

Introduction/Aim

Thromboembolism is a significant cause of patient morbidity and mortality, the risk of which increases in orthopaedic patients with lower limb immobilisation. It was therefore, our aim to identify a difference in symptomatic thromboembolism by treating acute Achilles tendon rupture patients with conventional non- weight bearing plaster versus functional weight bearing mobilisation.

Methodology

The notes of 91 consecutive patients with acute Achilles tendon rupture were reviewed. The patients' demographics, treatment modality (non- weight bearing plaster versus weight bearing boot), and predisposing risk factors were analysed. From the 91 patients, 50 patients with acute Achilles tendon rupture were treated conservatively in a non- weight bearing immobilisation cast. From these 50 patients, 3 then underwent surgery and were therefore excluded from the results. 41 patients were treated with functional weight bearing mobilisation. Patients who did have a symptomatic thromboembolic event had an ultrasound scan to confirm a deep vein thrombosis of the lower limb, or a CT-scan to confirm pulmonary embolism.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_X | Pages 19 - 19
1 Apr 2012
Aylott C Puna R Walker C Robertson P
Full Access

There is evidence that various anatomical structures have altered morphology with ageing, and anecdotal evidence of changing lumbar spinous process (LSP) morphology with age. This study aims to clarify the influence of age on LSP morphology, and on lumbar spine alignment.

200 CT scans of the abdomen were reformatted with bone windows allowing precise measurement of LSP dimensions and lumbar lordosis. Observers were blinded to patient demographics. Inter-observer reliability was confirmed.

The smallest LSP is at L5. The male LSP is on average 2-3mm higher and 1mm wider than the female LSP. LSP height increases significantly with age at every level in the lumbar spine (P<10-5 at L2). The LSPs increase in height by 2-5mm between 20-85 years of age (P<10-6), which was as much as 31% at L5 (P<10-8). Width increases proportionally more, by 3-4mm or greater than 50% at each lumbar level (P<10-11). Lumbar lordosis decreases in relation to increasing LSP height (P<10-4) but is independent of increasing LSP width (P=0.2).

The height and width of the spinous processes increases with age. Increases in spinous process height are related to a loss of lumbar lordosis and may contribute to sagittal plane imbalance.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 488 - 488
1 Nov 2011
Aylott C Puna R Walker C Robertson P
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Background: The Lumbar Spinous Processes (LSP) have an important anatomical and biomechanical function. They also influence access to the spinal canal for neural decompressive surgical procedures. There is evidence that various anatomical structures have altered morphology with ageing, and there is anecdotal evidence of changing LSP morphology with age. This study aims to clarify the influence of age on LSP morphology, and on lumbar spine alignment.

Method: 200 CT scans of the abdomen were reformatted with bone windows allowing precise measurement of LSP dimensions, and Lumbar Lordosis. Observers were blinded to patient demographics. Inter-observer reliability was confirmed.

Results: The smallest LSP is at L5. The male LSP is on average 2–3mm higher and 1mm wider than the female LSP. LSP height increases significantly with age at every level in the lumbar spine (P< 10-5 at L2). The LSPs increase in height by 2–5mm between 20–85 years of age (P< 10-6), which was as much as 31% at L5 (P< 10-8). Width increases proportionally more, by 3–4mm or greater than 50% at each lumbar level (P< 10-11). Lumbar lordosis decreases in relation to increasing LSP height (P< 10-4) but is independent of increasing LSP width (P=0.2).

Conclusions: The height and width of the spinous processes increases with age. Increases in spinous process height are related to a loss of lumbar lordosis and may contribute to sagittal plane imbalance.

Conflicts of Interest: None

Source of Funding: None


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 378 - 378
1 Jul 2011
Young S Walker C Poon P
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Cuff tear arthropathy represents a challenge to the shoulder arthoplasty surgeon. The poor results of conventional total shoulder arthroplasty in cuff deficient shoulders secondary to glenoid component loosening have meant hemiarthroplasty has traditionally been the preferred surgical option. Recently reverse total shoulder arthroplasty (RSA) has gained increasing popularity due to a clinical perception of an improved functional outcome, despite the absence of comparative data. The aim of this study was to compare the early functional results of Hemiarthroplasty versus RSA in the management of cuff-tear arthropathy.

102 primary hemiarthroplasties performed for cuff tear arthropathy were compared against 102 RSAs performed for the same diagnosis. Patients were identified from the New Zealand National Joint Registry and matched for age, sex, and American Society of Anesthesiologists (ASA) scores. Oxford shoulder scores (OSS) were collected at 6 months and 5 years post operatively and were compared between the two groups, together with mortality and re-revision rates.

There were 51 males and 51 females in each group, with a mean age of 71.6 in the Hemiarthroplasty group and 72.6 in the RSA group. The mean ASA score was 2.2 in both groups. The mean OSS was 31.1 in the hemiar-throplasty group and 38.1 in the RSA group. At follow up, there were 7 revisions in the hemiarthroplasty group and 5 in the RSA group. No difference in mortality was seen between the two groups.

This study provides the first direct evidence of a improved functional outcome of RSA compared to Hemiarthroplasty in the treatment of patients with cuff tear arthropathy. Longer term follow up is needed to confirm that the improved function is maintained, and that late complications such as component loosening remain comparable between the two groups.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 584 - 584
1 Oct 2010
Brookes-Fazakerley S Atkinson C Walker C
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Closure with interrupted mattress sutures is useful where careful skin apposition is required following hindfoot surgery. However, suture removal can be technically difficult and painful. Modification with an additional suture loop creates a “traction loop suture”. We hypothesise this technique makes suture removal quicker and reduced tension placed on sutures during their removal reduces pain.

37 patients undergoing elective hindfoot surgery took part in a prospective clinical trial comparing traditional interrupted sutures with traction loop sutures. Each patient underwent half of each wound sutured with both types. Sutures were removed at 2 weeks and pain levels were determined during removal using the 10 cm visual analogue pain scale. Duration of time taken for each type of suture removal was measured. Wound complications were recorded at 2 and 6 weeks post-operative.

Results demonstrated traction loop sutures were 43% less painful to remove per wound than normal interrupted sutures (mean difference 1.06; standard deviation 1.56; 95% confidence interval 0.50 to 1.62; p-value 0.001). Traction loop sutures were also 31% quicker to remove per wound (mean difference 15.72 seconds; standard deviation 19.98; confidence interval 8.51 to 22.93; p-value < 0.001). At 2 weeks, 1 normally sutured wound suffered dehiscence. At 6 weeks, no complications were noted in either group.

Our results demonstrate that traction loop sutures provide a quick and simple means of reducing patients’ pain and time during suture removal. Traction loop suturing technique could be applied to other surgical specialities where interrupted suture closure is indicated.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 338 - 338
1 May 2009
Pitto R Pandit S Clatworthy M Walker C Munro J
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Proximal tibial bone density (BD) is a key determinant in the migration of implants following total knee arthroplasty (TKA). CT-osteodensitometry offers three-dimensional, volumetric analysis of both cortical and cancellous regions and has been shown to be both accurate and reliable about the hip.

The primary objective of this study is to assess differences in the bone remodelling pattern (tibial segment) of patients operated on using fixed or rotating platform, using CT-osteodensitometry. The hypothesis is that the presence of a rotating platform optimises stress distribution along the proximal tibia, resulting in reduced proximal bone remodelling of tibia. The secondary objective is to correlate the osteodensitometry and clinical data at follow-up.

Following completion of the initial assessment and after obtaining written informed consent, the patients were randomly allocated to either a PFC Sigma fixed bearing or a PFC Sigma rotating platform (mobile bearing) total knee system (DePuy, Leeds, UK). Clinical follow-ups were performed at three months, one year, and two years after the index operation. CT scans were performed immediately post-operatively and at one and two years respectively. 52 knees (47 patients) were randomised for cemented TKR management using rotating or fixed tibia platform and followed up at one and two years.

At the two year follow-up, the knee function and patellar scores were comparable in both groups. There were no radiographic signs of loosening, and no revision surgery was performed. Sequential BD measurement from post-operative baseline to two year follow-up showed minimal differences between the fixed and rotating platform implants. Bone density assessment showed a 20% mean loss of cancellous BD and minimal changes of cortical BD, with little differences between the two groups. Loss of cancellous BD appears progressive.

In conclusion, this study shows that the mode of fixation of the TKR polyethylene liner does not influence bone remodelling of the proximal tibia after surgery. This is the first study performed to assess separately cortical and cancellous BD changes in THR. There are no data in the literature for comparison.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 172 - 173
1 Mar 2009
Young S Walker C Pitto R
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Introduction: Management of periprosthetic fractures following total hip arthroplasty (THA) represents a difficult clinical problem, requiring expertise in both trauma and revision surgery. Estimates of the prevalence of postoperative fracture range from 0.1% to 2.1%, and with rising numbers of patients in the population living with hip prostheses in situ there is evidence that their frequency is increasing. There remains a paucity of data on the functional outcome of these injuries, and the objective of this study was to analyse outcomes for revision THA following periprosthetic fracture, and compare these to elective revision surgery.

Methods: 233 patients (234 hips) undergoing revision THA for femoral fracture were identified from the New Zealand National Registry, and clinical outcomes were measured using Oxford Hip Scores (OHS) completed six months post operatively. A control group of 234 patients undergoing elective revision THA was selected and matched for age, sex, and time since index operation.

Results: Comparative analysis of the registry patients showed clinical outcomes were significantly worse following revision THA for fractured femur than in controls (mean OHS 28.6 vs 23.6, p=0.006), though this difference was not apparent in patients under the age of 65 years (mean OHS 26.1 vs 23.8, p =0.6). A higher mortality rate was found among fracture patients (17.1% versus 10.7 %, p=0.05), and a statistically significant higher number of periprosthetic fracture patients died within 6 months of their surgery in comparison to controls (7.3% versus 0.9%, p=0.003). A higher rate of re-revision was observed in the fracture group (7.7% versus 2.6%, p=0.02).

Conclusions: To our knowledge this study represents the largest comparative series of periprosthetic fractures in THA with functional outcome data yet reported. Management of patients with periprosthetic fractures requires recognition of the challenging nature of these injuries, their associated poor prognosis, and high complication rate.