Matrix-induced autologous chondrocyte implantation
(MACI) is an established technique used to treat osteochondral lesions
in the knee. For larger osteochondral lesions (>
5 cm2)
deeper than approximately 8 mm we have combined the use of two MACI
membranes with impaction grafting of the subchondral bone. We report
our results of 14 patients who underwent the ‘bilayer collagen membrane’
technique (BCMT) with a mean follow-up of 5.2 years (2 to 8). There
were 12 men and two women with a mean age of 23.6 years (16 to 40).
The mean size of the defect was 7.2 cm2 (5.2 to 12 cm2)
and were located on the medial (ten) or lateral (four) femoral condyles.
The mean modified Cincinnati knee score improved from 45.1 (22 to
70) pre-operatively to 82.8 (34 to 98) at the most recent review
(p <
0.05). The visual analogue pain score improved from 7.3
(4 to 10) to 1.7 (0 to 6) (p <
0.05). Twelve patients were considered
to have a good or excellent clinical outcome. One graft failed at
six years. The BCMT resulted in excellent functional results and durable
repair of large and deep osteochondral lesions without a high incidence
of graft-related complications.
Most proximal humeral fractures are stable injuries of the ageing population, and can be successfully treated non-operatively. The management of the smaller number of more complex displaced fractures is more controversial and new fixation techniques have greatly increased the range of fractures that may benefit from surgery. This article explores current concepts in the classification and clinical aspects of these injuries, reviewing the indications, innovations and outcomes for the most common methods of treatment.
We examined the morphology of mammalian hips asking whether evolution can explain the morphology of impingement in human hips. We describe two stereotypical mammalian hips, coxa recta and coxa rotunda. Coxa recta is characterised by a straight or aspherical section on the femoral head or head-neck junction. It is a sturdy hip seen mostly in runners and jumpers. Coxa rotunda has a round femoral head with ample head-neck offset, and is seen mostly in climbers and swimmers. Hominid evolution offers an explanation for the variants in hip morphology associated with impingement. The evolutionary conflict between upright gait and the birth of a large-brained fetus is expressed in the female pelvis and hip, and can explain pincer impingement in a coxa profunda. In the male hip, evolution can explain cam impingement in coxa recta as an adaptation for running.
The Oxford unicompartmental knee replacement (UKR) was designed to minimise wear utilising a fully-congruent, mobile, polyethylene bearing. Wear of polyethylene is a significant cause of revision surgery in UKR in the first decade, and the incidence increases in the second decade. Our study used model-based radiostereometric analysis to measure the combined wear of the upper and lower bearing surfaces in 13 medial-compartment Oxford UKRs at a mean of 20.9 years (17.2 to 25.9) post-operatively. The mean linear penetration of the polyethylene bearing was 1.04 mm (0.307 to 2.15), with a mean annual wear rate of 0.045 mm/year (0.016 to 0.099). The annual wear rate of the phase-2 bearings (mean 0.022 mm/year) was significantly less (p = 0.01) than that of phase-1 bearings (mean 0.07 mm/year). The linear wear rate of the Oxford UKR remains very low into the third decade. We believe that phase-2 bearings had lower wear rates than phase-1 implants because of the improved bearing design and surgical technique which decreased the incidence of impingement. We conclude that the design of the Oxford UKR gives low rates of wear in the long term.
The best method of reconstruction after resection of malignant tumours of the tibial diaphysis is unknown. In the absence of any long-term studies analysing the results of intercalary endoprosthetic replacement, we present a retrospective review of 18 patients who underwent limb salvage using a tibial diaphyseal endoprosthetic replacement following excision of a malignant bone tumour. There were ten men and eight women with a mean age of 42.5 years (16 to 76). Mean follow-up was 58.5 months (20 to 141) for all patients and 69.3 months (20 to 141) for the 12 patients still alive. Cumulative patient survival was 59% (95% confidence interval (CI) 32 to 84) at five years. Implant survival was 63% (95% CI 35 to 90) at ten years. Four patients required revision to a proximal tibial replacement at a mean follow-up of 29 months (10 to 54). Complications included metastases in five patients, aseptic loosening in four, peri-prosthetic fracture in two, infection in one and local recurrence in one. The mean Musculoskeletal Tumor Society score and the mean Toronto Extremity Salvage Score were 23 (17 to 28) and 74% (53 to 91), respectively. Although rates of complication and revision were high, custom-made tibial diaphyseal replacement following resection of malignant bone tumours enables early return to function and provides an attractive alternative to other surgical options, without apparent compromise of patient survival.
To assess the sensitivity and specificity of self-reported osteoporosis
compared with dual energy X-ray absorptiometry (DXA) defined osteoporosis,
and to describe medication use among participants with the condition. Data were obtained from a population-based longitudinal study
and assessed for the prevalence of osteoporosis, falls, fractures
and medication use. DXA scans were also undertaken.Objectives
Methods
We report the clinical and radiological outcome of total ankle replacement performed in conjunction with hindfoot fusion or in isolation. Between May 2003 and June 2008, 60 ankles were treated with total ankle replacement with either subtalar or triple fusion, and the results were compared with a control group of 288 ankles treated with total ankle replacement alone. After the mean follow-up of 39.5 months (12 to 73), the ankles with hindfoot fusion showed significant improvement in the mean visual analogue score for pain (p <
0.001), the mean American Orthopaedic Foot and Ankle Society score (p <
0.001), and the mean of a modified version of this score (p <
0.001). The mean visual analogue pain score (p = 0.304) and mean modified American Orthopaedic Foot and Ankle Society score (p = 0.119) were not significantly different between the hindfoot fusion and the control groups. However, the hindfoot fusion group had a significantly lower mean range of movement (p = 0.009) and a higher rate of posterior focal osteolysis (p = 0.04). Both groups showed various complications (p = 0.131) and failure occurring at a similar rate (p = 0.685). Subtalar or triple fusion is feasible and has minimal adverse effects on ankles treated with total ankle replacement up to midterm follow-up. The clinical outcome of total ankle replacement when combined with hindfoot fusion is comparable to that of ankle replacement alone. Thus, hindfoot fusion should be performed in conjunction with total ankle replacement when indicated.
An international faculty of orthopaedic surgeons
presented their work on the current challenges in hip surgery at
the London Hip Meeting which was attended by over
400 delegates. The topics covered included femoroacetabular impingement, thromboembolic
phenomena associated with hip surgery, bearing surfaces (including metal-on-metal
articulations), outcomes of hip replacement surgery and revision
hip replacement. We present a concise report of the current opinions
on hip surgery from this meeting with appropriate references to
the current literature.
The benefit of arthroscopy of the hip in the
treatment of femoroacetabular impingement (FAI) in terms of quality
of life (QoL) has not been reported. We prospectively collected
data on 612 patients (257 women (42%) and 355 men (58%)) with a
mean age at the time of surgery of 36.7 years (14 to 75) who underwent
arthroscopy of the hip for FAI under the care of a single surgeon.
The minimum follow-up was one year (mean 3.2 years (1 to 7)). The
responses to the modified Harris hip score were translated using
the Rosser Index Matrix in order to provide a QoL score. The mean
QoL score increased from 0.946 (-1.486 to 0.995) to 0.974 (0.7 to
1) at one year after surgery (p <
0.001). The mean QoL score
in men was significantly higher than in women, both before and one
year after surgery (both p <
0.001). However, the mean change
in the QoL score was not statistically different between men and
women (0.02 (-0.21 to 0.27) and 0.04 (-0.16 to 0.87), respectively;
p = 0.12). Linear regression analysis revealed that the significant predictors
of a change in QoL score were pre-operative QoL score (p <
0.001)
and gender (p = 0.04). The lower the pre-operative score, the higher
the gain in QoL post-operatively (ρ = -0.66; p <
0.001). One
year after surgery the QoL scores in the 612 patients had improved
in 469 (76.6%), remained unchanged in 88 (14.4%) and had deteriorated
in 55 (9.0%).
We conducted a retrospective study to investigate the effect of femoral bowing on the placement of components in total knee replacement (TKR), with regard to its effect on reestablishing the correct mechanical axis, as we hypothesised that computer-assisted total knee replacement (CAS-TKR) would produce more accurate alignment than conventional TKR. Between January 2006 and December 2009, 212 patients (306 knees) underwent TKR. The conventional TKR was compared with CAS-TKR for accuracy of placement of the components and post-operative alignment, as determined by five radiological measurements. There were significant differences in the reconstructed mechanical axes between the bowed and the non-bowed group after conventional TKR (176.2° ( For patients with significant femoral bowing, the reconstructed mechanical axes were significantly closer to normal in the CAS group than in the conventional group (179.2° (
We conducted a longitudinal study including patients with the same type of primary hybrid total hip replacement and evaluated patient activity and femoral osteolysis at either five or ten years post-operatively. Activity was measured using the University of California, Los Angeles scale. The primary outcome was the radiological assessment of femoral osteolysis. Secondary outcomes were revision of the femoral component for aseptic loosening and the patients’ quality of life. Of 503 hip replacements in 433 patients with a mean age of 67.7 years (30 to 91), 241 (48%) were seen at five and 262 (52%) at ten years post-operatively. Osteolytic lesions were identified in nine of 166 total hip replacements (5.4%) in patients with low activity, 21 of 279 (7.5%) with moderate activity, and 14 of 58 (24.1%) patients with high activity. The risk of osteolysis increased with participation in a greater number of sporting activities. In multivariate logistic regression adjusting for age, gender, body mass index and the inclination angle of the acetabular component, the adjusted odds ratio for osteolysis comparing high In conclusion, of patients engaged in high activity, 24% had developed femoral osteolysis five to ten years post-operatively.
The painful subluxed or dislocated hip in adults
with cerebral palsy presents a challenging problem. Prosthetic dislocation
and heterotopic ossification are particular concerns. We present
the first reported series of 19 such patients (20 hips) treated
with hip resurfacing and proximal femoral osteotomy. The pre-operative
Gross Motor Function Classification System (GMFCS) was level V in
13 (68%) patients, level IV in three (16%), level III in one (5%) and
level II in two (11%). The mean age at operation was 37 years (13
to 57). The mean follow-up was 8.0 years (2.7 to 11.6), and 16 of the
18 (89%) contactable patients or their carers felt that the surgery
had been worthwhile. Pain was relieved in 16 of the 18 surviving
hips (89%) at the last follow-up, and the GMFCS level had improved
in seven (37%) patients. There were two (10%) early dislocations;
three hips (15%) required revision of femoral fixation, and two
hips (10%) required revision, for late traumatic fracture of the
femoral neck and extra-articular impingement, respectively. Hence
there were significant surgical complications in a total of seven
hips (35%). No hips required revision for instability, and there
were no cases of heterotopic ossification. We recommend hip resurfacing with proximal femoral osteotomy
for the treatment of the painful subluxed or dislocated hip in patients
with cerebral palsy.
Previously, radiostereometric analysis following hip revision performed using impacted morsellised allograft bone and a cemented Exeter stem has shown continuous subsidence of the stem for up to five years. It is not known whether the subsidence continues thereafter. In our study, 17 of 25 consecutive osteo-arthritic patients with aseptically loose stems who underwent first-time revision using impacted morsellised allograft bone and a cemented Exeter stem were followed by yearly radiostereometric examinations for nine years. The mean subsidence at six weeks was 1.1 mm (0.1 to 2.3), from six weeks to one year 1.3 mm (0 to 2.6), from one to five years 0.7 mm (0 to 2.0), and from five to nine years 0.7 mm (0.1 to 3.1). That from six weeks to nine years was 2.7 mm (0 to 6.4) (95% confidence interval 2.0 to 3.5). The Charnley pain score significantly improved after revision, and was maintained at nine years, but walking ability deteriorated slightly as follow-up extended. Of the eight patients who were not followed for nine years, two had early subsidence exceeding 11 mm. Our findings show that in osteo-arthritic patients who undergo revision for aseptic loosening of the stem using impacted morsellised allograft bone and a cemented Exeter stem, migration of the stem continues over nine years at a slower rate after the first year, but without clinical deterioration or radiological loosening.
We have previously described the mid- to long-term
results of conventional simple varus intertrochanteric osteotomy
for osteonecrosis of the femoral head, showing that 19 of the 26
hips had good or excellent results. We extended the follow-up to
a mean of 18.1 years (10.5 to 26) including a total of 34 hips in
28 patients, with a mean age at surgery of 33 years (19 to 53).
There were 18 men and ten women and 25 hips (74%) had a satisfactory
result with a Harris hip score ≥ 80. In all, six hips needed total
hip replacement (THR) or hemiarthroplasty. The collapse of the femoral
head or narrowing of the joint space was found to have progressed
in nine hips (26%). Leg shortening after osteotomy was a mean of
19 mm (8 to 36). With conversion to THR or hemiarthroplasty as the
endpoint, the ten-year survival rate was 88.2% (95% confidence interval
(CI) 82.7 to 93.7) and the 20-year survival rate was 79.7% (95%
CI 72.1 to 87.3); four hips were converted at ten years and other
two hips were converted at 20 years. Shortening of the leg after osteotomy remains a concern; however,
the conventional varus half-wedge osteotomy provides favourable
long-term results in hips with less than two-thirds of the medial
part of the femoral head affected by necrotic bone and with normal
bone superolaterally.
Metal-on-metal (MoM) hip resurfacing was introduced into clinical
practice because it was perceived to be a better alternative to
conventional total hip replacement for young and active patients.
However, an increasing number of reports of complications have arisen
focusing on design and orientation of the components, the generation
of metallic wear particles and serum levels of metallic ions. The
procedure introduced a combination of two elements: large-dimension
components and hard abrasive particles of metal wear. The objective
of our study was to investigate the theory that microseparation
of the articular surfaces draws in a high volume of bursal fluid
and its contents into the articulation, and at relocation under
load would generate high pressures of fluid ejection, resulting
in an abrasive water jet. This theoretical concept using MoM resurfacing components (head
diameter 55 mm) was modelled mathematically and confirmed experimentally
using a material-testing machine that pushed the head into the cup
at a rate of 1000 mm/min until fully engaged.Objectives
Methods
The ideal acetabular component is characterised by reliable, long-term fixation with physiological loading of bone and a low rate of wear. Trabecular metal is a porous construct of tantalum which promotes bony ingrowth, has a modulus of elasticity similar to that of cancellous bone, and should be an excellent material for fixation. Between 2004 and 2006, 55 patients were randomised to receive either a cemented polyethylene or a monobloc trabecular metal acetabular component with a polyethylene articular surface. We measured the peri-prosthetic bone density around the acetabular components for up to two years using dual-energy x-ray absorptiometry. We found evidence that the cemented acetabular component loaded the acetabular bone centromedially whereas the trabecular metal monobloc loaded the lateral rim and behaved like a hemispherical rigid metal component with regard to loading of the acetabular bone. We suspect that this was due to the peripheral titanium rim used for the mechanism of insertion.
Compression and absolute stability are important in the management of intra-articular fractures. We compared tension band wiring with plate fixation for the treatment of fractures of the olecranon by measuring compression within the fracture. Identical transverse fractures were created in models of the ulna. Tension band wires were applied to ten fractures and ten were fixed with Acumed plates. Compression was measured using a Tekscan force transducer within the fracture gap. Dynamic testing was carried out by reproducing cyclical contraction of the triceps of 20 N and of the brachialis of 10 N. Both methods were tested on each sample. Paired The mean compression for plating was 819 N ( During simulated movements, the mean compression was reduced in both groups, with tension band wiring at −14 N ( Pre-contoured plates provide significantly greater compression than tension bands in the treatment of transverse fractures of the olecranon, both over the whole fracture and specifically at the articular side of the fracture. In tension band wiring the overall compression was reduced and articular compression remained negligible during simulated contraction of the triceps, challenging the tension band principle.
In this prospective study we studied the effect
of the inclination angle of the acetabular component on polyethylene wear
and component migration in cemented acetabular sockets using radiostereometric
analysis. A total of 120 patients received either a cemented Reflection
All-Poly ultra-high-molecular-weight polyethylene or a cemented
Reflection All-Poly highly cross-linked polyethylene acetabular
component, combined with either cobalt–chrome or Oxinium femoral
heads. Femoral head penetration and migration of the acetabular
component were assessed with repeated radiostereometric analysis
for two years. The inclination angle was measured on a standard
post-operative anteroposterior pelvic radiograph. Linear regression
analysis was used to determine the relationship between the inclination
angle and femoral head penetration and migration of the acetabular component. We found no relationship between the inclination angle and penetration
of the femoral head at two years’ follow-up (p = 0.9). Similarly,
our data failed to reveal any statistically significant correlation
between inclination angle and migration of these cemented acetabular
components (p = 0.07 to p = 0.9).