Advertisement for orthosearch.org.uk
Results 1 - 14 of 14
Results per page:
Applied filters
Content I can access

Include Proceedings
Dates
Year From

Year To
Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_11 | Pages 11 - 11
1 Jun 2016
O'Neill C Molloy D Patterson C Beverland D
Full Access

Introduction

Radiological Inclination (RI) is defined as the angle formed between the acetabular axis and the longitudinal axis when projected onto the coronal plane. Higher RI angles are associated with adverse outcomes.

Methods

Primary aim: to investigate the effect of adjusting patient pelvic position in the transverse plane by using a ‘head-down’ (HD) operating table position. This was to determine, when aiming for 35° Apparent Operative Inclination (AOI), which operating table position most accurately achieved a target post-operative RI of 42°.

N=270. Patients were randomised to one of three possible operating table positions:

0°HD (Horizontal),

7°HD, or

Y°HD (Patient Specific Table Position)

Operating table position was controlled using a digital inclinometer. RI was measured using EBRA software.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 95 - 95
1 Jan 2016
O'Neill CK Molloy D Patterson C Beverland D
Full Access

Background

The current orthopaedic literature demonstrates a clear relationship between acetabular component positioning, polyethylene wear and risk of dislocation following Total Hip Arthroplasty (THA). Problems with edge loading, stripe wear and squeaking are also associated with higher acetabular inclination angles, particularly in hard-on-hard bearing implants.

The important parameters of acetabular component positioning are depth, height, version and inclination. Acetabular component depth, height and version can be controlled with intra-operative reference to the transverse acetabular ligament.

Control of acetabular component inclination, particularly in the lateral decubitus position, is more difficult and remains a challenge for the Orthopaedic Surgeon. Lewinnek et al described a ‘safe zone’ of acetabular component orientation: Radiological acetabular inclination of 40 ± 10° and radiological anteversion of 15 ± 10°.

Accurate implantation of the acetabular component within the ‘safe zone’ of radiological inclination is dependent on operative inclination, operative version and pelvic position.

Traditionally during surgery, the acetabular component has been inserted with an operative inclination of 45°. This assumes that patient positioning is correct and does not take into account the impact of operative anteversion or patient malpositioning.

However, precise patient positioning in order to orientate acetabular components using this method cannot always be relied upon. Hill et al demonstrated a mean 6.9° difference between photographically simulated radiological inclination and the post-operative radiological inclination. The most likely explanation was felt to be adduction of the uppermost hemipelvis in the lateral decubitus position. The study changed the practice of the senior author, with target operative inclination now 35° rather than 40° as before, aiming to achieve a post-operative radiological inclination of 42° ± 5°.

Aim

To determine which of the following three techniques of acetabular component implantation most accurately obtains a desired operative inclination of 35 degrees:

Freehand

Modified (35°) Mechanical Alignment Guide, or

Digital inclinometer assisted


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 113 - 113
1 Jan 2016
Munir S Molloy D Hasted T Jack CM Shimmin A Walter W
Full Access

Sagittal stability of the knee is believed to be of significant importance following total knee arthroplasty. We examine four different knee designs at a minimum of twenty-four months postoperatively. Sagittal stability was measured at four degrees of flexion: 0°; 30°; 60°; and 90°, to examine the effect of design on mid-flexion stability.

The knee designs included were: the rotating platform LCS design (DePuy); the cruciate sparing Triathlon system (Stryker); SAIPH system (Matortho, UK); and the medial rotating knee design, MRK (Matortho, UK).

Following ethical approval, 64 cases were enrolled into the study, 22 male and 42 female. Inclusion criteria included: a minimum of 18 months from surgery; ability to flex beyond 90 degrees; and have no postoperative complications. 18 LCS, 18 MRK, 14 SAIPH and 14 Triathlon knee designs were analysed. Sagittal stability was measured using the KT1000 device. Active range of movement was measured using a hand held goniometer and recorded as was Oxford knee score, WOMAC knee score, SF12 and Kujala patellofemoral knee score.

Mean follow-up was 33.7 months postoperative, with a mean age of 72 years. Mean weight was 82.7kgs and height 164cms. There was no significant difference in preoperative demographics between the groups. Mean active post-operative range of motion of the knee was from 2–113° with no significant difference between groups.

Sagittal stability was similar in all four groups in full extension; however the MRK and SAIPH designs showed improved stability in the mid-range of flexion (30–90°). Patient satisfaction also showed a similar trend with MRK achieving better patient reported functional outcomes and satisfaction than that of the SAIPH, LCS and Triathlon systems.

All four knee designs demonstrated good post-operative range of movement with comparative improvement of patient scores to other reported studies. The MRK and SAIPH knee design showed an improved mid-flexion sagittal stability with better patient reported satisfaction and functional scores.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_12 | Pages 32 - 32
1 Nov 2015
O'Neill C Molloy D Patterson C Beverland D
Full Access

Introduction

Operative inclination (OI) is defined as the angle between the acetabular axis and the sagittal plane. With the patient in the true lateral decubitus position, this corresponds to the angle formed between the handle of the acetabular component inserter and the theatre floor intra-operatively.

Patients/Materials & Methods

The primary study aim was to determine which method of acetabular component insertion most accurately allows the surgeon to obtain a target OI of 35o.

270 consecutive patients undergoing cementless THA were randomised to one of three possible methods for acetabular component implantation:

1. Freehand,

2. 35o mechanical alignment guide (MAG), or

3. Digital inclinometer assisted

Two surgeons participated. Target OI was 35o in all cases. OI was measured using a digital inclinometer. For the freehand and MAG cases, the surgeon was blinded to inclinometer readings intra-operatively.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 85 - 85
1 Mar 2013
Molloy D Jenabzadeh R Walter W Hasted T
Full Access

Sagittal stability of the knee is believed to be of significant importance following a total knee arthroplasty. We examine three different knee designs at a minimum of twenty-four months postoperatively. Sagittal stability was measured at four degrees of flexion; 0°, 30°, 60° and 90° to examine the effect of design on mid-flexion stability.

The knee designs included the rotating platform LCS design, the cruciate sparing Triathlon system and the medial rotating knee design, MRK.

Following ethical approval 50 cases were enrolled into the study, 15 male and 35 female. Eighteen LCS, 18 MRK and 14 Triathlon knee designs were analysed. Sagittal stability was measured using the KT1000 device. Active range of movement was measured using a hand held goniometer and recorded as was Oxford knee score, WOMAC knee score, SF12 and Kujala patellofemoral knee score.

Mean follow-up was 37 months postoperative with a mean age of 73 years. Mean weight was 82.7 kgs and height 164 cms. There was no significant difference in preoperative demographics between the groups. Mean active post-operative range of motion of the knee was from 2–113° with no significant difference between groups.

Sagittal stability was similar in all three groups in full extension; however the MRK design showed improved stability in the mid-range of flexion (30–90°). Patient satisfaction also showed a similar trend with MRK achieving slightly better patient reported outcomes than that of the LCS and Triathlon systems, although this was not statistically significant.

All three knee designs demonstrated good post-operative range of movement with comparative improvement of patient scores to other reported studies. The MRK knee design showed an improved mid-flexion sagittal stability.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 127 - 127
1 Mar 2013
Cross MB Esposito C Sokolova A Jenabzadeh R Molloy D Munir S Zicat B Walter WK Walter WL
Full Access

Introduction

Modularity is being increasingly used throughout the world for both primary and revision total hip arthroplasty. Recently there have been concerns of increased corrosion and fretting at the modular junctions. In the SROM® modular hip system, two modular junctions are the head-neck taper junction and the stem-sleeve taper junction. The aim of this study was to investigate corrosion at these junctions with the use of different bearing materials.

Methods

Between 1994 and 2012, fourty-two patients were revised with SROM® stems. Reasons for revision included aseptic loosening of the cup or stem (11), periprosthetic fracture (2), osteolysis (8), dislocation (13) and other reasons (7). One was revised for stem breakage, and this was excluded from this study. We examined 41 retrieved S-ROM® comprised of 6 metal-on-metal (MOM), 12 metal-on-polyethylene (MOP), 7 ceramic-on-polyethylene (COP) and 16 ceramic-on-ceramic (COC). The orientation for all components was marked at the time of revision surgery. Both the proximal sleeve/stem and the femoral head-neck modular junctions were examined under 10X magnification, and graded by two independent observers. The head tapers were divided into 4 regions, and graded using a previously published 3 point scoring system for fretting and corrosion damage (Goldberg et al, Kop et al), for a total corrosion damage score of 12. The SROM stems were also assessed at the sleeve/stem taper junction. Each stem was divided into 8 quadrants, and graded for corrosion and fretting using the same system as the taper. In addition to severity, we also quantified area of corrosion damage of the stem at the sleeve-stem junction from 0–3, which was multiplied by the severity of damage, to give a score out of 9 for each quadrant (maximum total score of 72 for the stem). The bearing type was unknown to the investigators, so the grading was done in a blinded fashion. Corrosion scores were divided by time to account for differences in time to revision.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 420 - 420
1 Jul 2010
McConway JHF Wilson R Molloy D O’Brien S Archbold P Beverland D
Full Access

Aim: To develop a flexion jig that would reliably hold the post-op knee in fixed flexion for a defined time period and determine its influence on peri-operative blood loss, transfusion, pain, and complications (specifically nerve palsy)following TKA.

Methods/Results: A previous study in this department showed immediate postoperative flexion to significantly reduce blood loss following TKR. Following this study, time in flexion was increased to 12 hours in an attempt to further reduce blood loss., some patients then developed a painful lower limb nerve palsy. This palsy was caused by pressure from the jig in the popliteal fossa/calf on nerves. The design of the jig was altered to remove pressure from these areas. Because of this design change, we were unsure whether the new jig would have the same blood saving effect, necessitating a new study.

This prospective randomised controlled trial recruited 420 patients into 3 equal groups: extension, 3 & 6 hrs flexion.

This trial found a significant reduction in blood loss(12%, p=0.006) and length of stay(1/2 day, p=0.006) in the 6 hour flexion group, compared the extension group.

There was no significant difference in pain or complication rates (excluding nerve palsy).

2 patients in the 6 hour group had postoperative nerve palsy, however, this palsy was sensory only and markedly different to that found previously. Although the palsy rate in this study is similar(1.4%) to quoted literature rates (1.3%) for TKA, it is difficult to know if the jig was the cause of palsy as the there was a difference between those caused by the old metal jig (painful) and those in this study (sensory loss only).

Conclusion: The results of this study show post-op flexion for 6 hours to significantly reduce perioperative blood loss. Palsy was reduced to match rates as quoted in the literature.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 296 - 296
1 Jul 2008
Archbold HAP Mockford B Molloy D McConway J Ogonda L Beverland D
Full Access

Introduction: A critical determinant of early dislocation following total hip arthroplasty (THA) is correct positioning of the acetabular component. This challenging aspect of THA has not been lessened by the introduction of more minimally invasive techniques. In this paper we introduce a simple and reproducible technique, which uses the transverse acetabular ligament (TAL) to determine cup orientation. We have used this technique as the sole method of cup orientation in our last 1000 consecutive primary total hips.

Methods: One thousand consecutive patients were studied in order to determine the prevalence of early dislocation (within 3 months) following acetabular component placement determined by reference to the transverse ace-tabular ligament. All patients underwent primary total hip arthroplasty via a posterolateral approach with a posterior repair.

Results: At a minimum follow-up of 9 months (range 9–39 months) 6 of the 1000 hips (0.6%) had dislocated.

Conclusion: Although multiple factors are known to contribute to this rate correct placement of the acetabular component is critical. As our results compare favourably with other published series where a posterior repair has been performed by extrapolation we feel that that the TAL does provide an acceptable method of determining cup orientation. The fact that it is independent of patient position on the table and is easy to locate with a minimally invasive approach makes it an attractive method.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 254 - 254
1 May 2006
Molloy D Ogonda L Beverland D
Full Access

Objective: To examine the impact of aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) on preoperative haemoglobin levels and perioperative transfusion rates in patients undergoing total knee arthroplasty (TKA).

Methods: We examined the pre-operative haemoglobin (Hb) and haematocrit (Hct) of a consecutive series of 81 patients, looking at the relationship between the pre-operative use of Aspirin/NSAIDs on preoperative Hb, postoperative Hb deficit and the perioperative transfusion rate. A single surgeon performed all procedures using an LCS TKR (Depuy, Leeds UK). A standardised transfusion protocol was used.

Results: The patients were grouped according to their pre-operative use of aspirin or a NSAID, singly or in combination. The patient groups are as shown in the table below. All groups were comparable for age, BMI and ASA grade.

Results show a significantly higher transfusion rate (p=0.048) in the group of patients who received a combination of aspirin and a NSAID compared to the other groups. The patients on aspirin or a NSAID alone also had an increased transfusion rate but the increase was not statistically significant (p=0.12 and p=0.07 respectively).

Conclusion: The use of both aspirin and an NSAID in combination leads to a lower preoperative Hb and an increased post-operative transfusion requirement following total knee arthroplasty.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 281 - 281
1 May 2006
Archbold P Mohammed M O’Brien S Molloy D Beverland D
Full Access

Current methods for restoring or preserving limb length following total hip arthroplasty are anatomically inaccurate, as they do not consider acetabular and femoral height independently. In order to address this, we present and evaluate a technique that uses the transverse acetabular ligament to control the vertical height of the acetabular component and a caliper that controls the vertical placement of the femoral component within the femoral canal. Limb lengths were measured in 200 patients who had undergone primary total hip arthroplasty using this technique. Using this method, 94% had a post-operative limb length inequality that was 6 mm or less when compared to the normal side (average +0.38 mm). The maximum measured limb length inequality was ± 8 mm.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 251 - 251
1 May 2006
Molloy D McConway J Thompson N Beverland D
Full Access

Isolated patellofemoral osteoarthritis has been reported to occur in approximately 5% of patients with gon-arthrosis of the knee. A number of options are available for the surgical management of these individuals. We reported the short-term outcomes on thirty three patients (33 knees) with isolated patellofemoral osteoarthritis who underwent LCS total knee arthroplasty (TKA) without resurfacing who had been operated on between 1996 – 19991.

Barrack et al2 in 2001 reported on the incidence of anterior knee pain in two groups of TKA patients, one with patella resurfacing and one without. They reported an increase incidence of anterior knee pain in both groups.

We now report the longer-term outcomes with an average follow-up of 80.2months (range 54–94 months). At latest review, 9 patients experienced night time pain, all describing it as improved from their preoperative level. Twelve patients walked with the use of a walking aid, compared with 21 preoperatively. Disease specific scores at latest review showed improved outcome measures at latest review.

We also report our outcomes in an additional fifty-five patients (59 knees) with isolated patellofemoral osteoarthritis who were treated between 1999–2004 receiving an LCS total knee arthroplasty without patellar resurfacing. Our preliminary findings suggest that this technique continues to be an option in the management of the older patient with isolated patellofemoral osteoarthritis.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 182 - 182
1 Mar 2006
Molloy D Wilson R Beverland D
Full Access

Purpose: The objective of this study was to examine the relationship between aspirin and other non-steroidal anti-inflammatory drugs (NSAIDS) on postoperative blood loss following Total Knee Arthroplasty

Methods: We prospectively examined the pre-operative consumption of aspirin and NSAIDS and haematological parameters of 50 consecutive patients undergoing Total Knee Arthroplasty. 22 (44%) patients were on aspirin only, 17 (34%) patients on aspirin and another NSAID and 11 (22%) patients were taking neither aspirin nor a NSAID. (All patients received 150mg of aspirin the evening before surgery as DVT prophylaxis).

Results: The average pre-operative haemoglobin of the group taking aspirin and a NSAID, aspirin only and neither aspirin nor NSAID group was 12.9g/dl, 13,8g/dl and 13.49g/dl respectively. The drop between their pre-operative level and Day 3 Haemoglobin level was 3.788g/dl, 4.45g/dl and 4.28g/dl respectively.

The same trend was reflected in the PCV drops of 0.111, 0.133 and 0.1273 respectively. Transfusion rates for the three groups showed that those on aspirin and another NSAID had the highest rate with an average of 0.235 units per patient compared to 0.136 for those on aspirin only and 0.10 for those on neither aspirin nor NSAID.

Discussion: These findings indicate that the ingestion of aspirin or a NSAID preoperatively does not increase the amount of blood loss following total knee arthroplasty (TKA). The higher transfusion rates in the aspirin and NSAID group is because of the lower preoperative haemoglobin as compared to the other groups studied.

Conclusion: Observation of transfusion trends within our unit has shown a transfusion rate of 18% in patients with a preoperative Haemoglobin level of greater than 13.0g/dl as compared to 48% with a haemoglobin level of 13.0g/dl or less (review of 180 consecutive patients undergoing Total Knee Arthroplasty).

The ingestion of aspirin and NSAID does not increase blood loss following TKA but significantly have a lower preoperative Hb level. We feel that pre-operative Haemoglobin levels are the best predictors of transfusion requirements following total knee arthroplasty.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 44 - 44
1 Mar 2006
Wilson R Molloy D Elliott J Mawhinney D
Full Access

Introduction: Hip fractures affects more than 65,000 people in the UK each year and this number is increasing. The standard treatment is insertion of either a dynamic hip screw or hemiarthroplasty depending on fracture configuration. Because of their advanced age, associated co-morbid factors as well as having had an implant inserted, hip fracture patients are at increased risk of developing post-operative wound infections. The infection rate for hip fracture surgery is quoted at 0.6 – 3.6%1.

Methods: We carried out a retrospective study of the readmission rate due to wound infection following treatment of their fractured neck of femur. 20 patients (16 females and 4 males) were identified over a 24 month period out of a total 1786 femoral neck fractures treated (1.1%).

Results: 11 patients re-admitted with a wound infection had had a hemiarthroplasty fixation, 9 following insertion of a DHS. 7 patients (0.4%) had a superficial wound infection (3 hemi, 4 DHS) and 13 (0.7%) a deep wound infection (8 hemi, 5 DHS). Treatment for the superficial wound infections included 6 patients requiring IV antibiotics and 1 requiring washout and resuturing of the wound.

Treatment of deep wound infections included 6 who had a Girdlestone procedure, 2 had wound washout, debridement and 2 who had removal of DHS. All received IV antibiotics. 2 patients were deemed unfit for surgery and received IV antibiotics only.

3 patients with a deep wound infection (23%) died (2 deemed unfit for surgery, and 1 Girdlestone) during their admission. 85% of the readmissions had an ASA score of three or over. We looked at the length of operation time and found that 15 took less than 45 minutes, 4 took between 45 and 60 minutes and one took over 60 minutes. Three of the operations which took over 45 minutes developed deep infections.

Conclusion: Fractured neck of femur accounts for a large proportion of fracture admissions. Accepted methods of treatment carry significant infection rates. Superficial wound infections can in the majority be treated with IV antibiotics. Deep wound infections carry a significant mortality rate. Operating time should be within 45 minutes where possible to reduce the risk of deep infection. Post-operative wound infections are associated with an ASA grade of 3 or greater.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 264 - 264
1 Sep 2005
Wilson RK Mockford B Molloy D Beverland DE
Full Access

Purpose: The objective of this study was to observe the change in transfusion rate by decreasing the transfusion trigger for patients undergoing primary total knee arthroplasty.

There are no transfusion guidelines defined for Total knee arthroplasty (TKA), and each orthopaedic unit usually has its own protocol when it comes to transfusion. With the present climate of concern about non-autologous blood transfusions and transmission of infection, orthopaedic units are trying to keep their transfusion rates to a minimum and only transfuse when absolutely necessary.

Method: The transfusion trigger prior to protocol change was a haematocrit (Hct) < 0.31, which was then changed to a lesser trigger of Hct < 0.25. We collected data on 331 patients; 181 patients prior to the change and 150 patients after the change. Each patient had undergone a primary TKA by a single surgeon using the same operative technique.

Results: In the group prior to change in transfusion trigger (Hct < 0.31), 76% of patients were transfused 88% of females and 54% of males. In this pre-trigger change group, 100% of patients with a pre-operative Hb of 12g/dl or less were transfused.

Of the 150 patients reviewed after the change in transfusion trigger (Hct < 0.25), only 29% were transfused – 35% of females and 18% of males. 50% of patients with a pre-operative Hb of 12 g/dl or less were transfused.

Conclusion: A change in the transfusion trigger greatly reduced the transfusion rate (reduction of 45%) with no adverse patient events. Obviously, this has both clinical and financial benefits. Pre-operative Hb is the best indicator as to whether a patient will require a transfusion following TKA. In order to decrease transfusion rates further, patients with a pre-operative Hb < 12 g/dl may benefit from pre-operative boosting of their Hb.