Study Aim

To assess the impact of two oral thromboprophylaxis agents against Clexane with regard to range of movement (ROM) following TKR with or without haemostasis following tourniquet release.

Introduction

Osteochondral defects of the knee may occur following patella dislocation or following direct trauma or twisting injuries to the knee in adolescents. Often a diagnostic and therapeutic challenge, if these lesions are left, posttraumatic osteoarthritis may occur. This retrospective single centre study presents the short-term results following operative fixation of osteochondral fragments of the knee using Omnitech ® screws.

Introduction

This study investigates the effect of Rivaroxaban (Bayer HealthCare) on early post-operative stiffness in primary total knee replacement.

Purpose

This study investigates the effect of early tourniquet release on range of flexion following total knee replacement, and the influence of anticoagulation with Rivaroxaban and Clexane (Enoxaparin).

Introduction

Hydroxyapatite (HA) coated femoral stems require a press fit for initial stability prior to osteointegration occurring. However this technique can lead to perioperative femoral fracture.

We investigated factors that were thought to be associated with an increased incidence of squeaking of ceramic-on-ceramic total hip replacements. Between June 1997 and December 2008 the three senior authors implanted 2406 primary total hip replacements with a ceramic-on-ceramic bearing surface. The mean follow-up was 10.6 years. The diagnosis was primary osteoarthritis in each case, and no patient had undergone previous surgery to the hip. We identified 74 squeaking hips (73 patients) giving an incidence of 3.1% at a mean follow-up of 9.5 years (4.1 to 13.3).

Taller, heavier and younger patients were significantly more likely to have hips that squeaked. Squeaking hips had a significantly higher range of post-operative internal (p = 0.001) and external rotation (p = 0.003) compared with silent hips. Patients with squeaking hips had significantly higher activity levels (p = 0.009). A squeaking hip was not associated with a significant difference in patient satisfaction (p = 0.24) or Harris hip score (p = 0.34). Four implant position factors enabled good prediction of squeaking. These were high acetabular component inclination, high femoral offset, lateralisation of the hip centre and either high or low acetabular component anteversion.

This is the largest study to date to examine patient factors and implant position factors that predispose to squeaking of a ceramic-on-ceramic hip. The results suggest that factors which increase the mechanical forces across the hip joint and factors which increase the risk of neck-to-rim impingement, and therefore edge-loading, are those that predispose to squeaking.

The medium term results of the JRI Furlong Total hip replacement have been very impressive to date. We report the longest prospective series to date of a hydroxyapatite coated femoral prosthesis (Joint Replacement Instrumentation limited, London, UK) at 15–21 years follow up. We describe the long term clinical and radiological femoral stem survival of 331 consecutive JRI Furlong Hydroxyapatite coated total hip replacements in 291 patients at an average follow-up of 17.5 years (15 – 21 year). Two patients (0.6%) were lost to follow-up over the 21 years of the study period. Using revision of the femoral stem for any reason as an endpoint, we report a stem survival of 97.4 % (81.0 to 99.5). Using Aseptic loosening as an endpoint, stem survival was 100%.

The average Merle, D’Aubine & Postel scores recorded for the patients was 5.63/6 for Pain, 5.42/6 for mobility and 4.50/6 for function. There were no cases of anterior thigh pain relating to the uncemented femoral stem.

These results compare favourably with the best long term survival of cemented or uncemented femoral stems used in total hip replacements.

Previously ankylosed or surgically arthrodesed hip joints can be converted successfully to a total hip replacement (THR) in order to improve patient mobility and function. We present a long term prospective cohort study of cementless revisions of previously ankylosed hips.

Sixteen hips (15 patients) with a mean age of 52 years (range 16 to 75) had ankylosed hips for a mean of 36 years (range 3.5 to 65 years). They all received a cementless THR between August 1988 and January 2003 and were prospectively followed-up for a mean of 11 years (range 5.0 to 19 years). Two patients died during the study period of unrelated causes and none were lost to follow-up.

All patients showed improved mobility and function following the conversion of their ankylosed hips. The Harris Hip Score improved from a pre-operative mean value of 70 (Standard Error of Mean (SEM) 3.4) to a post-operative value of 83 (SEM 4.4) at the latest review, which was statistically significant (p < 0.05).

There was one acetabular cup revision at 5 years post implantation for aseptic loosening. At a mean of 11 years post THR, all other femoral and acetabular components remained clinically and radiographically well fixed. One patient with systemic ankylosing spondylitis and spontaneous bilateral bony hip ankylosis developed the unusual complication of Paget’s disease of the left hemipelvis and proximal femur two years after successful bilateral THR surgery. His symptoms resolved following medical therapy for Paget’s disease.

We conclude that a previously ankylosed hip can be effectively converted to a cementless total hip replacement with good long term results.

Previously ankylosed or surgically arthrodesed hip joints can be converted successfully to a Total Hip Replacement (THR) in order to improve patient mobility and function. We present a long term prospective cohort study of cementless revisions of previously ankylosed hips.

Sixteen hips (15 patients) with a mean age of 52 years (range 16 to 75) had ankylosed hips for a mean of 36 years (range 3.5 to 65 years). They all received a cement-less THR between August 1988 and January 2003 and were prospectively followed-up for a mean of 11 years (range 5.0 to 19 years). Two patients died during the study period of unrelated causes and none were lost to follow-up.

All patients showed improved mobility and function following the conversion of their ankylosed hips. The Harris Hip Score improved from a pre-operative mean value of 70 (Standard Error of Mean (SEM) 3.4) to a post-operative value of 83 (SEM 4.4) at the latest review, which was statistically significant (p < 0.05). There was one acetabular cup revision at 5 years post implantation for aseptic loosening. At a mean of 11 years post THR, all other femoral and acetabular components remained clinically and radiographically well fixed.

One patient with systemic ankylosing spondylitis and spontaneous bilateral bony hip ankylosis developed the unusual complication of Paget’s disease of the Left hemipelvis and proximal femur two years after successful bilateral THR surgery. His symptoms resolved following medical therapy for Paget’s disease.

We conclude that a previously ankylosed hip can be effectively converted to a cementless total hip replacement with good long term results.

Dislocation remains a common complication following total hip arthroplasty, second only to aseptic loosening as a cause of revision. Factors thought to play a role in dislocation include cup and stem alignment, soft tissue tension, surgical approach, patient factors, and design features of the prosthesis, including femoral head size.

We analysed all consecutive total hip replacements at one institution over a 17 year period. Criteria for study inclusion were hips replaced due to primary osteoarthritis with no previous surgery, femoral head sizes of 28mm and 32mm only, and at least one year from date of surgery. 3682 hips fulfilled these criteria. All procedures were carried out using a posterolateral approach with enhanced posterior repair, and a standard method of intraoperative soft tissue balance assessment.

The rate of dislocation was 1.6%. 32mm femoral head size was associated with a statistically significant lower rate of dislocation. However, after controlling for different follow-up times between 28mm and 32mm heads, this difference was no longer observed. Older age at time of surgery and decreased cup anteversion were shown to be significantly associated with an increased risk of dislocation. Ceramic on ceramic bearing surface was significantly associated with a decreased risk of dislocation, after controlling for age, bearing wear and time from surgery. Cup inclination, gender, BMI, and preoperative hip score were not related to dislocation risk.

Our dislocation rate may reflect current dislocation rates of surgeons using the posterolateral approach with posterior capsule and external rotator repair. The risk factors identified and excluded in this study are likely to be relevant to all surgeons who utilise this approach in total hip arthroplasty.

Dislocation remains a common complication following total hip arthroplasty, second only to aseptic loosening as a cause of revision. Factors thought to play a role in dislocation include cup and stem alignment, soft tissue tension, surgical approach, patient factors, and design features of the prosthesis, including femoral head size.

We analysed all consecutive total hip replacements at one institution over a 17 year period. Criteria for study inclusion were hips replaced due to primary osteoarthritis with no previous surgery, femoral head sizes of 28mm and 32mm only, and at least one year from date of surgery. 3682 hips fulfilled these criteria. All procedures were carried out using a posterolateral approach with enhanced posterior repair, and a standard method of intraoperative soft tissue balance assessment.

The rate of dislocation was 1.6%. 32mm femoral head size was associated with a statistically significant lower rate of dislocation. However, after controlling for different follow-up times between 28mm and 32mm heads, this difference was no longer observed. Older age at time of surgery and decreased cup anteversion were shown to be significantly associated with an increased risk of dislocation. Ceramic on ceramic bearing surface was significantly associated with a decreased risk of dislocation, after controlling for age, bearing wear and time from surgery. Cup inclination, gender, BMI, and preoperative hip score were not related to dislocation risk.

Our dislocation rate may reflect current dislocation rates of surgeons using the posterolateral approach with posterior capsule and external rotator repair. The risk factors identified and excluded in this study are likely to be relevant to all surgeons who utilise this approach in total hip arthroplasty.

We report a consecutive series of 200 patients who underwent Dynesys flexible stabilisation in the management of intractable lower back pain.

Methods: Patients were only accepted for the study if exhaustive conservative management had failed. They underwent operation between September 2000 and March 2003. Patients were divided into two groups:

Group 1 - Cases where implantation was used as an adjunct to other procedures including decompression, discectomy, or posterior lumbar interbody fusion. (32 male, 36 female, Mean age 56years (range 31–85)).

Group 2 - Patients with back pain and/or sciatica in which no other procedure was used. (65 male 67 female, Mean age 58years (range 27–86))

All patients were profiled prospectively using the Oswestry Disability Index (ODI), SF36 and Visual Analogue Scale (VAS). Patients were reviewed post-operatively using the same measures at 3, 6 & 12 months, and yearly thereafter. Follow-up was 95% at 2 to 5 years.

Results: Group 1 – Mean ODI fell from 54 pre-op to 24 at four years

Group 2 – Mean ODI fell from 49 pre-op to 28 at four years

Similar trends were observed in both groups with a fall in VAS and improvement in SF36.

Discussion: Indications can only be defined following clinical outcome. Perceived indications were based on contemporary understanding of the biomechanical effects of the construct. Further investigation of these variables is clearly desirable. Screw failures (15%) have detracted from the overall success. The virtue of flexible stabilisation over fusion includes avoidance of domino effect, reversibility and possible healing of a painful segment. The key issue is whether it is as effective and this requires prospective randomised controlled investigation, both against fusion, and conservative management. We feel our results in this difficult group of patients are reasonable and continue to use it in our practice.

Introduction Dynesys flexible stabilisation was developed by Giles Dubois in 1992, and first used in 1994 (1). Our unit has undertaken 375 operations to date. We report a consecutive series of 200 patients who underwent Dynesys flexible stabilisation in the management of intractable lower back pain.

Methods Access to our spinal service is exclusively from a back assessment centre run by a triaging nurse practitioner who works closely with the senior author. Conservative treatment is arranged by the centre, and includes physiotherapy to the point of failure. Patients were only accepted for the study if exhaustive conservative management had failed. They underwent operation by the senior author between September 2000 and March 2003. Patients were divided into two groups: Group 1 – Cases where implantation was used as an adjunct to other procedures including decompression, discectomy, or posterior lumbar interbody fusion. (32 male, 36 female, Mean age 56years (range 31–85)) Group 2 – Patients with back pain and/or sciatica in which no other procedure was used. (65 male 67 female, Mean age 58years (range 27–86)) All patients were profiled prospectively using the Oswestry Disability Index (ODI), SF36 and Visual Analogue Scale (VAS). Patients were reviewed post-operatively using the same measures at 3, 6 and 12 months, and yearly thereafter. Follow-up was 95% at 2 to 5 years.

Results Group 1 – Mean ODI fell from 54 pre-op to 24 at four years. Mean SF36 improved from 43 pre-op to 56 at four years Group 2 – Mean ODI fell from 49 pre-op to 28 at four years. Mean SF36 improved from 40 pre-op to 62 at four years. Similar trends were observed in both groups at five years with these favourable scores tending back towards pre-operative levels. Screw failures, either loosening or fracture, occurred at a rate of 15% over the follow-up period.

Discussion Our results support the use of flexible stabilisation as an alternative to spinal fusion. There is currently no consensus on absolute indications for the procedure however. Such indications can only be defined following clinical outcome. Perceived indications were based on contemporary understanding of the biomechanical effects of the construct. Further investigation of these variables is clearly desirable. Screw failures (15%) have detracted from the overall success, although the relationship between such failures and poor outcomes is complex and difficult to elucidate at the current time. The virtue of flexible stabilisation over fusion includes avoidance of domino effect, reversibility and possible healing of a painful segment. The key issue is whether flexible stabilisation is as effective and this requires prospective randomised controlled investigation, both against fusion, and against conservative management. We feel our results in this difficult group of patients are reasonable and continue to use it in our practice.

Introduction: It is unknown what effect distraction osteogenesis has on bone blood flow to the affected limb. Our study analyzed in vivo measurement of tibial blood flow during distraction osteogenesis using Doppler ultrasonography.

Materials and Methods: Blood flow was measured in the femoral artery, with Doppler ultrasonography in five people treated with bi-focal tibial distraction osteogenesis. The normal leg was used as the control to correct for differences in cardiac output. Measurements for each leg were taken and means recorded preoperatively, at 1 week postoperatively, and at subsequent intervals up to 6 months.

Results: Preoperative blood flow varied from 0.5 – 2.25. All treated legs demonstrated increases in flow from 2.25 – 5.75, with peaks in the first weeks following osteotomy. Significant increases in blood flow during treatment with distraction osteogenesis, confirming previous experimental studies.

Discussion: Blood flow plays a significant role in the successful outcome of this treatment. Compression of the non-union at the time of peak blood flow gives more reliable union than bone transport methods, where docking takes place when blood flow has returned towards the control limb.

Aims: Anterior knee pain is a common complaint of mixed aetiology, and in many cases no demonstrable cause is identified. For patients with persistant anterior knee pain, tibial tubercle transfer (TTT) can be a surgical option. The aim of this study is to assess the effectiveness of TTT for chronic anterior knee pain resistant to conservative treatment. Method: All patients with arthroscopically proven Chondromalacia patellae (CMP) without clinical evidence of patella instability, who have failed to respond to conservative treatment such as physiotherapy were included in the trial. They underwent TTT with a modified Fulkerson technique and then routine post-operative care with a cricket pad splint for 2–4 weeks. Pre and post-operative scores were obtained using a Kujala patello-femoral score, a visual analogue score for pain and a patient satisfaction score. The Outerbridge grading was used to score the severity of CMP at arthroscopy. Results: There were 50 TTT’s followed up (7 staged bilaterals) with a mean follow up of 32.4 months (5–88 months). There were significant improvement in the pre-operative and post-operative Kujala (p> 0.001) and visual analogue pain scores (p> 0.001). Of the 50 TTT’s 70% had an excellent or good result and 30% a fair or poor result. Moreover 76% claimed that they would have the same operation again for their condition. There was no significant correlation between Outerbridge grading and post-operative outcome. Complications include late anterior knee pain (10 cases), superficial wound infection (1 case), non-union of osteotomy (1 case) and tuberosity fracture (1 case). Conclusion: Anteromedial tibial tubercle transfer is a reliable and effective treatment for peristant anterior knee pain.

Introduction: We report a series of 90 patients enrolled in a prospective study of Dynesys stabilisation reviewed at 12 to 30 months.

The procedure involves, at each segment, cephalad and caudad pedicle screws connected with a polycarbourethane spacer and polyethylene cord. It achieves load relief and controlled flexion. Since 1996, 7000 procedures have been undertaken globally.

Method: Indications are analogous to consideration for fusion. Entry criteria included 1) Unresolved and unacceptable lumbar back pain despite protracted conservative management and 2) Definite pathology where symptoms could be abolished by anaesthetising the target segments.

Where root compression was present, a midline approach and posterior screw placement was used in conjunction with open decompression. With back pain alone a bilateral Wiltse approach and posterolateral placement was used.

All patients were assessed pre and post surgery with SF36, Oswestry Disability Index and pain analogue scores and modified Zung. Standing radiographs were obtained post surgery and at review. Follow up was at 6, 12, 24 and 52 weeks in addition to this review.

Results: Follow up was 100%. 89 patients survived. Mobilisation was achieved on day 1 and discharge usually by day 2.Based on the above outcome measures and patient satisfaction good to excellent results were achieved in 74%(66/89). Screw loosening or breakage occurred in 8%, and was associated with a poor result.

Discussion: Dynesys flexible stabilisation offers a simple alternative to fusion with less potential for adjacent ‘Domino’ failure. It differs from tension ligament systems such as Graf. At this stage the results appear at least as good as a comparable cohort of fusion patients.

The present series is early, but gives grounds for encouragement. Screw loosening and failure are technical problems detracting from the result and require further development.

We are continuing to use the technique.

INTRODUCTION: We report a series of 90 patients enrolled in a prospective study of Dynesys stabilisation reviewed at 12 to 30 months.

The procedure involves, at each segment, cephalad and caudad pedicle screws connected with a polycarbo-urethane spacer and polyethylene cord. It achieves load relief and controlled flexion. Since 1996, 7000 procedures have been undertaken globally.

METHOD: Indications are analogous to consideration for fusion. Entry criteria included (1) unresolved and unacceptable lumbar back pain despite protracted conservative management and (2) definite pathology where symptoms could be abolished by anaesthetising the target segments.

Where root compression was present, a midline approach and posterior screw placement was used in conjunction with open decompression. With back pain alone a bilateral Wiltse approach and posterolateral placement was used.

All patients were assessed pre- and post-surgery with SF36, Oswestry Disability Index and pain analogue scores and Modified Zung. Standing radiographs were obtained post- surgery and at review. Follow-up was at six, 12, 24 and 52 weeks in addition to this review.

RESULTS: Follow-up was 100%. 89 patients survived. Mobilisation was achieved on day 1 and discharge usually by day 2. Based on the above outcome measures and patient satisfaction good to excellent results were achieved in 74% (66/89). Screw loosening or breakage occurred in 8%, and was associated with a poor result.

DISCUSSION: Dynesys flexible stabilisation offers a simple alternative to fusion with less potential for adjacent ‘Domino’ failure. It differs from tension ligament systems such as Graf. At this stage the results appear at least as good as a comparable cohort of fusion patients.

The present series is early, but gives grounds for encouragement. Screw loosening and failure are technical problems detracting from the result and require further development.

We are continuing to use the technique.