Aims

Will Hydroxyapatite hip (HA) arthroplasty associated with ceramic bearings produce uncomplicated function in younger, active patients’ The incidence of aseptic loosening, dislocation and broken implants has been particularly investigated.

Debris disease from plastic debris contributes to aseptic loosening. Hard-Hard bearings should obviate this problem. Metal-metal will release ions which might be deleterious. Experience with metal-metal resurfacing has high lighted problems including pseudo-tumours. Ceramic bearings may fracture but otherwise appear free of complications.

We report the early results of a patello-femoral prosthesis with a more anatomical trochlear component than previously reported designs, and with a patella component, geometry and instrumentation that allows optimum tracking and coverage of the patella, prior to final fixation of the patella component.

The first 115 patello-femoral prostheses were implanted between April 2000 and October 2005, and were followed up in a Special Clinic by one observer, who was not the operating surgeon, using the Bristol Knee Score (BKS), and the Oxford Knee Score (OKS). 115 patello-femoral arthroplasties were performed in 86 patients, 28 bilateral procedures (24.3%). 20 (71%) of which were performed as a single procedure. There were 100 females and 15 males, a ratio of 6.6:1, with a mean age of 70.05 years. (range 57 – 79). There were 9 patients lost to follow up, giving a follow up rate of 89%. The mean period follow up was 36 months (range 12 – 78 months). The median OKS (maximum 12/60) was 40/60 pre-operatively (range 22-46) and 22/60 Post-operatively (range 12 – 38), and the BKS was 45 pre-operatively (range 35 – 65) and 85 post-operatively (range 55 – 100). The mean range of movement was 110° pre-operatively (range 90 – 120°), and 125° (range 90 – 130°) post-operatively.

There was 1 superficial wound infection. 2 knees were revised to total knee replacement for progression of arthritis. Four other patients had re-operations, 1 for bilateral subluxing patellae, 2 for soft tissue problems, 1 patient had a locked knee with displacement of the patella prosthesis, which was revised successfully.

Early results of the FPV prosthesis demonstrate, like other more recent designs, that there are fewer problems with mal alignment and mal tracking than with earlier prosthesis, giving 90% good or excellent results.

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.

Background: Spinal fusion for degenerative disc disease remains a controversial issue due to adjacent segment disease. Several alternatives have been evaluated; including Dynamic Neutralisation System for Spine and artificial disc arthroplasty. In our cohort study, we are highlighting advantages of DYNESYS over TDA and fusion as being a simple and reversible procedure if removal of implants is necessary.

Materials and Methods: Prospective cohort study on 415 patients underwent DYNESYS. The implant has to be removed in 43 patients. Patients were evaluated preoperatively using Oswestry Disability Index, SF 36 and Visual Analogue Scores together with plain imaging and MRI scanning. Preoperative discography was performed in 81% of patients. Questionnaires were evaluated on subsequent follow up at 3 & 6 months, 1 year then at annual intervals.

Results: Average treatment period was 26 months with a range from 3/12 to 60/12. The main reason for DYNE-SYS removal was screws’ failure or loosening followed by infections. The implant was used to treat single disc space in 20.9%, two spaces in 67.4% and three disc spaces in 9.3%. 81% of the screws were not Hydroxy-appetite coated. No loosening was detected among HA coated screws.

Outcome assessment revealed significant improvement in SF36 even after removal of stabilising system while no worsening of ODI or VAS in comparison with preoperative status.

Conclusions: DYNESYS can maintain disc height and restricts movements exceeding physiological limits. HA coated screws have superior biomechanical characteristics in preventing screw loosening and subsequent spinal spasms. If necessary, removal of implants is a simple procedure.

Background: Spinal fusion for degenerative disc disease remains a controversial issue due to adjacent segment disease. Several alternatives have been evaluated; including Dynamic Neutralisation System for Spine and artificial disc arthroplasty. In our cohort study, we are highlighting advantages of DYNESYS over TDA and fusion as being a simple and reversible procedure if removal of implants is necessary.

Material & Methods: Prospective cohort study on 415 patients underwent DYNESYS. The implant has to be removed in 43 patients. Patients were evaluated preoperatively using Oswestry Disability Index, SF 36 and Visual Analogue Scores together with plain imaging and MRI scanning. Preoperative discography was performed in 81% of patients. Questionnaires were evaluated on subsequent follow up at 3/12, 6/12 then at annual intervals.

Results: Average treatment period was 26 months with a range from 3/12 to 60/12. The main reason for DYNE-SYS removal was screws’ failure or loosening followed by infections. The implant was used to treat single disc space in 20.9%, two spaces in 67.4% and three disc spaces in 9.3%. 81% of the screws were not Hydroxy Appetite coated. No loosening was detected among HA coated screws.

Outcome assessment revealed significant improvement in SF36 even after removal of stabilising system while no worsening of ODI or VAS in comparison with preoperative status.

Conclusions: DYNESYS can maintain disc height and restricts movements exceeding physiological limits. HA coated screws have superior biomechanical characteristics in preventing screw loosening and subsequent spinal spasms. If necessary, removal of implants is a simple procedure.

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.