Aims

The primary aim of this independent prospective randomised trial was to compare serum metal ion levels for ceramic-on-metal (CoM) and metal-on-metal (MoM) bearing surfaces in total hip arthroplasty (THA). Our one-year results demonstrated elevation in metal ion levels above baseline with no significant difference between the CoM and MoM groups. This paper reviews the five-year data.

In a double-blinded randomised controlled trial, 83 patients with primary osteoarthritis of the hip received either a ceramic-on-metal (CoM) or metal-on-metal (MoM) total hip replacement (THR). The implants differed only in the bearing surfaces used. The serum levels of cobalt and chromium and functional outcome scores were compared pre-operatively and at six and 12 months post-operatively.

Data were available for 41 CoM and 36 MoM THRs (four patients were lost to follow-up, two received incorrect implants). The baseline characteristics of both cohorts were similar. Femoral head size measured 36 mm in all but two patients who had 28 mm heads. The mean serum cobalt and chromium levels increased in both groups, with no difference noted between groups at six months (cobalt p = 0.67, chromium p = 0.87) and 12 months (cobalt p = 0.76, chromium p = 0.76) post-operatively. Similarly, the mean Oxford hip scores, Western Ontario and McMaster Universities Osteoarthritis index and University of California, Los Angeles activity scores showed comparable improvement at 12 months.

Our findings indicate that CoM and MoM couplings are associated with an equivalent increase in serum cobalt and chromium levels, and comparable functional outcome scores at six and 12-months follow-up.

Despite a large body of literature the optimal choice of bearing surface for total hip arthoplasty (THA) remains controversial. To avoid the brittleness and squeaking noted with ceramic-on-ceramic and the metal ion release associated with metal-on-metal (MOM) articulations, a novel hybrid coupling of ceramic-on-metal (COM) has been introduced. The purpose of this study was to compare changes in serum metal ion levels and the functional performance of COM and MOM bearing combinations.

Eighty-six patients (86 hips) undergoing THA between April 2009 and October 2010 were randomized to COM or MOM bearing couplings. All received identical uncemented acetabular shells and femoral components from two experienced surgeons using the same operative technique.

Demographic and peri-operative data were recorded. Serum cobalt and chromium levels, renal function and disease specific outcome scores (Oxford Hip, Harris Hip, UCLA activity) were assessed at baseline, 6 and 12 months post-operatively. Patients and outcome assessors remained blinded.

Mean age of the total cohort was 62.5 years. Randomization successfully matched groups for age, Body Mass Index, baseline serum Cobalt and Chromium levels, and pre-operative functional performance scores. One-year data is currently available for 25 of 44 COM and 26 of 42 MOM patients. No significant difference in serum cobalt (P value = 0.81) and chromium (P value = 0.66) levels between groups was noted. Improvements in outcome scores (Oxford Hip, Harris Hip, UCLA activity) were equivalent (P values 0.16 – 0.46).

At 1-year, COM and MOM hip arthroplasty articulations appear equivalent in terms of function and serum metal ion levels. Data collection out to 5-years post-surgery continues.

The aim of this study is to determine evidence-based guidelines on functional outcomes following common thoracolumbar injuries using a synthesis of systematic literature reviews and consensus expert opinion

A questionnaire was created comprising five cases representative of common thoracolumbar injuries (a thoracic compression fracture, a flexion distraction injury and burst fractures each with varied location, patient demographics and treatment strategies). For each scenario five questions about expected functional outcomes were posed. Questionnaires were distributed to the Spine Trauma Study Group. Responses were combined with available data from a systematic review of the same injuries and outcomes to create consensus evidence based guidelines.

The survey was completed by 31 (57%) of 53 surgeons representing 20 centres across North America. The systematic reviews identified 49 appropriate studies. One year following a L1 burst fracture, a heavy laborer, treated with protective mobilization (cast or brace) has a 40% chance of being pain free, 70% chance of regaining pre-injury range of motion, can expect to be re-employed within 4–6 months and be able to participate in high impact exercise and contact sport with no or minimal limitation. Length of inpatient stay averages 4–5 days. One year following posterior short segment stabilization of a L1 bust fracture in a college football player, there is an expected 45% chance of being pain free and 55% chance of regaining pre-injury ROM. While an ultimate return to high impact exercise and contact sports is anticipated, 32% of experts expect the injury to end a college football career.

Results for the other trauma scenarios are included.

This combination of literature and expert opinion represents the best available evidence on functional prognosis after thoracolumbar trauma. By providing consistent, accurate information surgeons and other care path providers will help patients develop realistic expectations, which may shape and improve their ultimate outcome.

The aim of this study was to evaluate the results of a consecutive series of distal tibial fractures treated by percutaneous plating.

85 patients with distal tibial fractures were treated using minimally invasive medial plate fixation. 18 patients had open fractures. Eight had displaced intra-articular fractures (AO type 43C). The majority had extra-articular fractures (AO type 42 or 43A). Patients ranged in age from 16–89 years. All were followed to union with a minimum follow-up period of 6 months (average 47 months). Outcome measures assessed retrospectively were alignment, time to full weight bearing and complications including infection, delayed or non-union and secondary surgery.

The mean time to surgery after injury was 5 days (range 0–22). 51 patients had unlocked pre-contoured plates and the remaining 34 had locking plates. The fibula was plated in 41 cases. Post-operative mal-alignment greater than 5 degrees varus or valgus occurred in 3 cases (3.5%). The average time to full weight bearing was 11 weeks. Superficial infection occurred in 6 patients (7%) and deep infections in 4 cases (4.7%). There was one case of plate fracture. 4 patients, including this case, required further surgery to achieve union. There was a high rate of metalware symptoms that prompted plate removal.

Percutaneous plate fixation of distal tibial fractures is a reliable method of treatment with complication rates lower than reported for open techniques.

The aim of this study was to examine the results of medial opening wedge high tibial osteotomies in which TRISOITE (hydroxyapatite tricalcium phosphate composite) wedges have been used as bone graft substitute and to compare the histological results with the clinical outcome.

There were 36 medial opening wedge high tibial osteotomy performed in 33 patients with a mean age of 45 years. Medial compartment osteoarthritis with varus alignment was the indication in 32 patients. All were followed to union with a minimum follow up of 6 months (average 50 months).

The surgical technique involved creating an oblique upper tibial osteotomy at an angle of 60 degrees from distal-medial to proximal lateral, passing distal to the insertion of the patellar ligament and preserving the lateral cortex. The osteotomy was opened to the desired angle of correction and preformed Triosite wedges were inserted. Stabilisation was obtained with a contoured titanium T-plate (ENZTEC). Re-operation was required for metal removal or conversion to total knee replacement in 10 cases. All of these patients had a biopsy of the osteotomy site.

The clinical notes and x-rays were retrospectively reviewed. One patient developed a superficial infection post-operatively which was successfully treated with intravenous antibiotics. Bone grafting was required to achieve union in 1 case (2.8%). There were no cases of varus deformity recurrence as a result of graft collapse. Biopsies provided microscopic evidence of bony incorporation around the tricalcium phosphate with bone healing. Three patients were converted to total knee replacement with no problems at the osteotomy site.

Triosite wedges appear to be a reliable synthetic bone graft substitute to act as a scaffold for bone healing in opening wedge osteotomies. They reduce the morbidity associated with iliac crest bone graft.