Abstract

The current study aims to ascertain the outcome of ACI with simultaneous transplantation of an autologous bone plug for the restoration of osteoarticular defects in the femoral condyle of the knee (‘Osplug’ technique).

Seventeen patients (mean age of 27±7 years), twelve with Osteochondritis dissecans (OD) and five with an osteochondral defect (OCD) was treated with unicortical autologous bone graft combined with ACI (‘Osplug’ technique). Functional outcome was assessed with Lysholm scores obtained for 5 years post-operatively. The repair site was evaluated with the Oswestry Arthroscopy Score (OAS), MOCART MRI score and ICRS II histology score.

The mean defect size was 4.5±2.6 SD cm² and mean depth was 11.3±5 SD mm. A significant improvement of Lysholm score from 45 (IQR 24, range 16–79) to 77 (IQR 28, range 41–100) at 1 year (p-value 0.001) and 70 (IQR 35, range 33–91) at 5 years (p-value 0.009). The mean OAS of the repair site was 6.2 (range 0–9) at a mean of 1.3 years. The mean MOCART score was 61 ± 22SD (range 20–85) at 2.6 ± 1.8SD years. Histology demonstrated generally good integration of the repair cartilage with the underlying bone. Poor lateral integration of the bone graft on MRI and low OAS were significantly associated with a poor outcome and failure.

The Osplug technique shows significant improvement of functional outcome for up to 5 years. This is the first report describing the association of bone graft integration with functional outcome after such a procedure.

Summary

Randomised controlled study evaluating new bone formation in vivo in fracture non-unions by bone marrow derived stromal cells (BMSC). These cells do not show statistically significant new bone formation. Age of the patient during fracture, diabetes and doubling time had been observed to be correlated with fracture healing.

Aim

To evaluate the efficacy of bone marrow derived stromal cells (BMSC) for the treatment of non-unions in fractures.

Introduction

Meniscus deficiency leads to the development of early arthritis. Total knee replacement may be the only available treatment option in certain situations. However it is generally best avoided in young patients. We hypothesized that a combination of the two procedures, Allograft Meniscal Transplantation (AMT) and Autologous Chondrocyte Implantation (ACI) would be a solution to treat bone-on-bone arthritis in meniscal deficient knees and postpone the need for a total knee replacement (TKR).

Introduction

Regenerative medicine is a rapidly expanding discipline. However due to a lack of validated outcome measures, clinical trials have been far few. This study aims to assess the validity, inter-observer reliability and intra-observer reproducibility of experimental fracture healing assessment on plain radiographies. This technique involves implantation of mesenchymal stem cell (MSC) seeded constructs on only one side of the fracture after randomisation.

Background

Autologous Chondrocyte Implantation (ACI) is frequently used to treat chondral defects in the knee with a good long-term outcome. This is contraindicatd in meniscal deficient knees. Allogenic Menicsal Transplantation (AMT) has been shown to give good symptomatic relief in meniscus deficient knees. However this is contraindicated in advanced cartilage degeneration. We hypothesized that combination of these two might be a solution for bone-on-bone arthritis in young individuals.

Background

Thrust plate prosthesis (TPP) is a bone conserving prosthesis in use for over thirty years. TPP is a stemless and uncemented femoral prosthesis fixed at the lateral femoral cortex with a bolt, plate and screw. This has a metal-on-metal articulation with a 28mm Metasul head and Allofit press fit acetabular cup. Our study aimed to assess the functional outcome of this prosthesis.

Background

Autologous Chondrocyte Implantation (ACI) is a procedure which is gaining acceptance for the treatment of cartilage defects in the knee with good results and a long term durable outcome. Its use in other joints has been limited, mainly to the ankle. We aimed to assess the outcome of ACI in the treatment of chondral and osteochondral defects in the hip.

Background

Hip resurfacing has resurged in the last decade due to a renewed interest in metal on metal bearing. One of the proposed advantages is ease of revision of the femoral component. Short term functional results after femoral revision are similar to those after conventional total hip replacement. Survival and function after revision of the acetabular component only or of both components have not been reported. We aimed to assess hip function and implant survival after revision of the acetabular component for failed Birmingham hip resurfacing (BHR).

Thrust plate prosthesis (TPP) is a bone conserving prosthesis in use for over thirty years. TPP is a stemless and uncemented femoral prosthesis fixed at the lateral femoral cortex with a bolt, plate and screw. This has a metal-on-metal articulation with a 28mm Metasul head and Allofit press fit acetabular cup. Our study aimed to assess the survival of this prosthesis. At Oswestry 234 TTP's were implanted between 1995 and 2005. All patients completed a self-assessed questionnaire of Harris Hip Score pre-operatively and post-operatively at 2 months, 1 year, and then yearly. Only those who had a follow up was within the last two years were included in the analysis. 76 patients who had failed to satisfy the criteria were excluded. Of the 158 hips in the study 75 hips were in male patients and 83 were in female patients. The median age of patients was 52 years (range 15 to 82). 75 hips were on the right side and 83 on the left. All patients were operated by the senior author or a senior trainee under his supervision (seven hips). Revision of the implant or decision to revise was taken as the end point of our study. The median time to follow up was 7 years (range 1 to 15). The median pre-operative hip score was 43 (range 3 to 77) which rose to 83 points (range 11 to 100) at the latest follow up. Median hip score in females improved from 39 to 82 points and in males from 52 to 85 points. Twelve patients (5.1%) underwent revision surgery either for infection or aseptic loosening. The Thrust Plate Prosthesis had a good outcome with an increase in hip score of 40 points and 94.9 % survival at a median of 7 years.

A new surgical hybrid technique involving the combination of autologous bone plug(s) and autologous chondrocyte implantation (AOsP-ACI) was used and evaluated as a treatment option in 15 patients for repair of large osteochondral defects in knee (N=12) and hip joints (N=3). Autologous Osplugs were used to contour the articular surface and the autologous chondrocytes were injected underneath a biological membrane covering the plug. The average size of the osteochondral defects treated was 4.5cm². The average depth of the bone defect was 26mm. The patients had a significant improvement in their clinical symptoms at 12 months with significant increase in the Lysholm Score and Harris Hip Score (p = 0.031). The repaired tissue was evaluated using Magnetic Resonance Imaging, Computerised Tomography, arthroscopy, histology and immunohistochemistry (for expression of type I and II collagen). Magnetic Resonance Imaging, Computerised Tomography and histology at 12 months revealed that the bone plug became well integrated with the host bone and repair cartilage. Arthroscopic examination at 12 months revealed good lateral integration of the AOsP-ACI with the surrounding cartilage. Immunohistochemistry revealed mixed fibro-hyaline cartilage. We conclude that the hybrid AOsP-ACI technique provides a promising surgical approach for the treatment of patients with large osteochondral defects. This study highlights the use of this procedure in two different weightbearing joints and demonstrates good early results which are encouraging. The long term results need to be evaluated.

Hip resurfacing with metal-on-metal in patients with osteonecrosis (ON) raises concerns of early failure. This study addresses the hypothesis that osteonecrosis as a pre-operative diagnosis significantly increases the risk of failure following hip resurfacing. We analyzed data of 202 hips that underwent metal-on-metal hip resurfacing. In group 1 were 101 hips with a pre-operative diagnosis of osteonecrosis. In group 2 were 101 hips with other pre-operative diagnosis of osteoarthritis. Survival analysis with Cox regression was used to compare the revision risks of both groups. The mean age at operation was 42 years in osteonecrotic and 43 years in osteoarthritic group. The preoperative and postoperative hip scores were 62 and 96 for osteonecrotic group and 58 and 95 for osteoarthritic group, respectively. Survival analysis with revision for any reason as the endpoint was performed on the two groups which had identical follow-up periods. Survival at 10 years was 97.7% for osteonecrosis and 95.0% for osteoarthritis. The revision risk for patients with osteonecrosis was lower (0.37, 95% CI 0.07 – 1.82, Cox regression) but the difference was not significant (p = 0.19). Our study found no difference in revision risk in patients with osteonecrosis as compared to those with osteoarthritis

We aimed to assess the long term results of patients who underwent Autologous Chondrocyte Implantation (ACI) for osteochondral lesions of the talus. Between 1998 and 2006, 28 patients underwent ACI for osteochondral lesions of the talus. All these patients were prospectively reviewed and assessed for long term results. Outcomes were assessed using satisfaction scores, Mazur ankle score and the AOFAS score, and Lysholm knee score for donor site morbidity.

The 28 patients who underwent the procedure included 18 males and 10 females. Follow up ranged from 1–9 years. In all patients, there was an improvement in the Mazur and AOFAS ankle scores and the Lysholm scores showed minimal donor site morbidity. Improvement in ankle score was independent of age and gender. The better the pre-op score the less the difference in post-op ankle scores. Patients were unlikely to benefit with pre-op ankle scores over 75.

The mid to long term results of ACIs in the treatment of localised, contained cartilage defects of the talus are encouraging and prove that it is a satisfactory treatment modality for symptomatic osteochondral lesions of the talus. Complications are limited. However, in view of limited number of patients, a multi-centre randomised controlled study is required for further assessment.

Thirty-five patients were followed prospectively from their referral to the Problem Fracture Service with chronic osteomyelitis of diaphyseal bone between November 1994 and June 1999.

The patients were treated using a closed double-lumen suction irrigation system following reaming and arthroscopic debridement of the intramedullary canal; this is a modified system based on the work of Charles Lautenbach. Results of these procedures were regularly followed up in clinic, and between June and July 2007 the whole cohort was reviewed via postal questionnaire, telephone and case note review.

At a mean follow up of 101 months, 26 were living with no evidence of recurrence, 4 had died of unrelated causes with no evidence of recurrent infection. Four patients had persisting problems with sinus discharge requiring intermittent antibiotic therapy and 1 patient had his limb amputated for recurrent metaplastic change.

These results gave this cohort an 86% clearance of infection, with recurrence in 12%, which is comparable to the Papineau and Belfast techniques with significantly less surgical insult to the patient.

Conversion of failed femoral components of total hip resurfacing to conventional hip replacement is reportedly a straightforward procedure. There is little published to qualify this and what is available suffers from small study numbers and various combinations pre and post-operative implants.

Between 1997 and 2002, the Oswestry Outcome Centre prospectively collected data on 5000 Birmingham Hip Resurfacings (BHRs) performed by 141 surgeons, at 87 hospitals. To date 4526 have survived, 135 died and 165 are lost to follow-up. 174 have been revised, of which 60 were failures of the femoral component. We reviewed modes of failure and post-revision clinical outcomes in this sub-group.

Isolated femoral component failure accounted for 60 hips (1.2%). 28 femoral neck fractures, 14 femoral head collapses, 13 femoral component loosenings, 3 avascular necroses (AVN), 1 femoral loosening followed by fracture and 1 dislocation. Mean time to revision surgery was 2.6 years (1.8 years for neck fracture; 3.4 years femoral loosening, head collapse and AVN). All acetabular components were left in situ. At revision surgery 25 cemented, 25 uncemented and 10 unknown femoral prostheses were used with 56 BHR modular heads, 2 custom-made Exeter heads and 2 Thrust Plate heads. 47 patients completed outcome scores post-revision surgery. Median modified Harris Hip Score was 82 (IQ range=63–93) and Merle d’Aubigne score was 14 (IQ= 9.5–15) at a mean follow up of 3.9 years post-revision. The 4526 surviving resurfacings had a median hip score of 96 (IQ=87–100) p≤4.558x10-8 and median Merle score of 17 (IQ=14–18) p≤1.827x10-7. Mean 7.0 years follow up. There was no difference in outcomes between cemented and un-cemented revision components nor were there differences between fractured neck of femur and femoral loosening, head collapse or AVN.

Following revision of the femoral component to a conventional hip replacement, function is significantly worse than surviving resurfacings.

Introduction: Autologous chondrocyte implantation (ACI) has been used most commonly as a treatment for cartilage defects in the knee and there are few studies of its use in other joints. There is only one published report of its use in the hip. Is there a role for ACI of the hip?

Materials and Methods: We describe fourteen consecutive patients studied prospectively with chondral or osteochondral lesions of the femoral head that underwent ACI and were prospectively reviewed with a follow up of 5 years (mean 30 months).

Three patients presented with Perthes and five with AVN. Four had chondral loss following trauma and one presented with an area of bone loss in a hip with congenital dysplasia. Defect size was a mean 6.2 cm2.

Pre-operatively hip function was assessed by the patient using the Harris Hip Score and MRI. Postoperatively these were repeated at 1 year and hip scores repeated annually.

Hip arthroscopy and cartilage biopsy provided Cells for culture in a GMP laboratory where passage numbers were limited to two. Three weeks later by open surgery, all unstable cartilage was excised, the base was debrided or excised and bone graft applied, and suture of a membrane of periosteum or collagen membrane over the defect undertaken. A mean 5.2 million chon-drocytes were inserted beneath this patch following a test of the seal.

Results: Ten of the fourteen patients improved at one year, with a mean rise in Harris Hip score from 57 to 63 points. Five patients underwent arthroscopic examination at one year and in four there was evidence of good integration of the new cartilage. In one patient arthros-copy was difficult due to previous trauma. One patient developed AVN as a post-operative complication following a posterior approach. Four patients have progressed to hip replacement or resurfacing but it is of note that all these patients had cyst formation pre-operatively.

Conclusion: The short-term results of ACI for osteo-chondral lesions of the hip suggest that if good early results are obtained they are observed to continue out to 5 years. There is a high failure rate in those with pre-operative cyst formation in the hip

Introduction: Conversion of failed femoral components of total hip resurfacing to conventional hip replacement is reportedly a straightforward procedure. There is little published to qualify this and what is available suffers from small study numbers and various combinations pre and post-operative implants.

Method: Between 1997 and 2002, the Oswestry Outcome Centre prospectively collected data on 5000 Birmingham Hip Resurfacings (BHRs) performed by 141 surgeons, at 87 hospitals. To date 4526 have survived, 135 died and 165 are lost to follow-up.

174 have been revised, of which 60 were failures of the femoral component.

We reviewed modes of failure and post-revision clinical outcomes in this sub-group.

Results: Isolated femoral component failure accounted for 60 hips (1.2%). 28 femoral neck fractures, 14 femoral head collapses, 13 femoral component loosenings, 3 avascular necroses (AVN), 1 femoral loosening followed by fracture and 1 dislocation. Mean time to revision surgery was 2.6years (1.8years for neck fracture; 3.4years femoral loosening, head collapse and AVN).

All acetabular components were left in situ. At revision surgery 25 cemented, 25 uncemented and 10 unknown femoral prostheses were used with 56 BHR modular heads, 2 custom-made Exeter heads and 2 Thrust Plate heads.

47 patients completed outcome scores post-revision surgery. Median modified Harris Hip Score was 82 (IQ range=63–93) and Merle d’Aubigne score was 14 (IQ= 9.5–15) at a mean follow up of 3.9years post-revision.

The 4526 surviving resurfacings had a median hip score of 96 (IQ=87–100) p≥4.558x10-8 and median Merle score of 17 (IQ=14–18) p≥1.827x10-7. Mean 7.0 years follow up.

There was no difference in outcomes between cemented and uncemented revision components nor were there differences between fractured neck of femur and femoral loosening, head collapse or AVN.

Discussion: Following revision of the femoral component to a conventional hip replacement, function is significantly worse than surviving resurfacings.

Introduction: Hip resurfacing is a renaissance of metal on metal hip arthroplasty. It preserves bone stock and a large head allows greater range of motion. This new technique is gaining popularity among patients and surgeons alike. We present a nine year follow up in the context of survival, function and complications.

Methods: We analysed follow up data of 4778 patients who have had hip resurfacing using Birmingham Hip resurfacing (Smith & Nephew, UK) in 37 countries. Patients were followed up annually using Oswestry hip score and any revisions were updated on the database at the Oswestry Outcome Centre. Function was analysed using multilevel modelling and Kaplan-Meier method used for survival analysis.

Results: There were 3193 males and 1585 females operated by 138 surgeons in 37 countries. The mean age was 52.8 years (13 – 87.8). Using hierarchical regression the annual hip scores were analysed. Overall function was significantly affected by pre op score and gender (p< 0.01). Age at operation had no effect on outcome score (p =.462).

We observed similar effect in individual domains of pain, mobility and range of motion. Survival of the implant at nine years with revision due to any reason was 93.5%. We observed a significant difference in survival of procedures done by pioneer surgeons and by non pioneering surgeons (p < 0.01) (log rank test). There were 119 complications of which there were 30 fractures, 21 occurring within the first six months of operation.

Conclusion: Nine year results of hip resurfacing arthroplasty look promising and are comparable to traditional hip arthroplasty. The difference between two surgeon groups could be due to a learning curve in the technique. Further follow up would be necessary to ascertain the long-term clinical effectiveness of this technique.

Introduction: Total hip replacement in one of the most commonly performed operation in orthopaedics in the UK with similar numbers being operated in other parts of the world (2). The main reasons for this magnitude are marked improvement in function and the quality of life. The hip prosthesis has evolved significantly over half a century and better prostheses are available today. These newer implants are required to have a survival of 90% for a minimum of 10 years. The improved survival of the implant tends to have effect on the quality of life as well as the life expectancy. There has been a continuous attempt to quantify this increased life expectancy and survival following total hip arthroplasty.

Materials and Methods: We compared the mortality figures of 3947 patients who had hip resurfacing arthroplasty with the national mortality figures of the UK. The cause of death was determined by telephone call to the next of kin and from the national death register.

Results: The average standardized mortality ratio of hip resurfacing patients compared to national figures over the nine year period was 0.524(99 percent C.I. 0.39 to 0.69). Individual SMR for each year is shown in Table. The number of observed deaths were 86 as compared to the expected deaths number 164. Out of the total 86 deaths over a nine year period, 36 deaths were due to cancer, 25 due to cardiovascular causes, eight due to respiratory conditions, four following accidents and 13 due to other causes such as suicide, old age. In the cancer group 7 patients died of lung cancer and 8 died of blood cell neoplasms. National figures for year 2007 were not yet compiled so SIR for cancer was not calculated.

Conclusion: The results of this study are comparable to other follow up studies on mortality following total hip replacement. This indicates that increased activity following hip resurfacing may help the patients maintain better fitness.

The incidence of cancer needs to be interpreted with caution and can only be ascertained by a prospective study.