Patients with skeletal dysplasia are prone to
developing advanced osteoarthritis of the knee requiring total knee replacement
(TKR) at a younger age than the general population. TKR in this
unique group of patients is a technically demanding procedure owing
to the deformity, flexion contracture, generalised hypotonia and ligamentous
laxity. We retrospectively reviewed the outcome of 11 TKRs performed
in eight patients with skeletal dysplasia at our institution using
the Stanmore Modular Individualised Lower Extremity System (SMILES)
custom-made rotating-hinge TKR. There were three men and five women
with mean age of 57 years (41 to 79). Patients were followed clinically
and radiologically for a mean of seven years (3 to 11.5). The mean
Knee Society clinical and function scores improved from 24 (14 to
36) and 20 (5 to 40) pre-operatively, respectively, to 68 (28 to
80) and 50 (22 to 74), respectively, at final follow-up. Four complications
were recorded, including a patellar fracture following a fall, a
tibial peri-prosthetic fracture, persistent anterior knee pain,
and aseptic loosening of a femoral component requiring revision.
Our results demonstrate that custom primary rotating-hinge TKR in
patients with skeletal dysplasia is effective at relieving pain,
with a satisfactory range of movement and improved function. It compensates
for bony deformity and ligament deficiency and reduces the likelihood
of corrective osteotomy. Patellofemoral joint complications are
frequent and functional outcome is worse than with primary TKR in
the general population.
We carried out a prospective investigation into
the radiological outcomes of uncemented Oxford medial compartment
unicondylar replacement in 220 consecutive patients (231 knees)
performed in a single centre with a minimum two-year follow-up.
The functional outcomes using the mean Oxford knee score and the
mean high-activity arthroplasty score were significantly improved
over the pre-operative scores (p <
0.001). There were 196 patients
with a two-year radiological examination performed under fluoroscopic
guidance, aiming to provide images acceptable for analysis of the
bone–implant interface. Of the six tibial zones examined on each
knee on the anteroposterior radiograph, only three had a partial
radiolucent line. All were in the medial aspect of the tibial base plate
(zone 1) and all measured <
1 mm. All of these patients were
asymptomatic. There were no radiolucent lines seen around the femoral
component or on the lateral view. There was one revision for loosening
at one year due to initial inadequate seating of the tibial component.
These results confirm that the early uncemented Oxford medial unicompartmental
compartmental knee replacements were reliable and the incidence
of radiolucent lines was significantly decreased compared with the
reported results of cemented versions of this implant. These independent
results confirm those of the designing centre.
Bicruciate-stabilised total knee replacement (TKR) aims to restore normal kinematics by replicating the function of both cruciate ligaments. We performed a prospective, randomised controlled trial in which bicruciate- and posterior-stabilised TKRs were implanted in 13 and 15 osteo-arthritic knees, respectively. The mean age of the bicruciate-stabilised group was 63.9 years ( At near full extension during step-up, the bicruciate-stabilised TKR produced a higher mean PTA than the posterior-stabilised TKR, indicating that the bicruciate design at least partially restored the kinematic role of the anterior cruciate ligament. The bicruciate-stabilised TKR largely restored the pre-operative kinematics, whereas the posterior-stabilised TKR resulted in a consistently lower PTA at all activities. The PTA in the pre-operative knees was higher than in the control group during the step-up and at near full knee extension. Overall, both groups generated a more normal PTA than that seen in previous studies in high knee flexion. This suggested that both designs of TKR were more effective at replicating the kinematic role of the posterior cruciate ligament than those used in previous studies.
We compared the medium-term clinical and radiological results of hybrid total hip replacement (THR) with metal-on-metal Birmingham hip resurfacing (BHR) in two groups of 54 young patients matched for age, gender, body mass index and pre-operative levels of activity. The clinical outcome was assessed by the University of California, Los Angeles (UCLA) activity score, the Oxford Hip Score (OHS) and the EuroQol scores. Radiologically, all hips were assessed for migration and osteolysis, the hybrid THRs for polyethylene wear and the BHRs for a pedestal sign. The mean follow-up of the patients with a hybrid THR was ten years and for those with a BHR, nine years. Four patients with a hybrid THR and one with a BHR had died. In each group five were lost to follow-up. The revision rate of the hybrid THRs was 16.7% (9 of 54) and of the BHRs 9.3% (5 of 54) (p = 0.195). Radiographs of a further eight hybrid THRs demonstrated wear and osteolysis, and they await revision (p = 0.008). Of the unrevised BHRs 90% had radiological changes, of which approximately 50% had progressed over the previous four years. All hybrid THRs demonstrated linear polyethylene wear with a mean of 1.24 mm (0.06 to 3.03). The BHRs recorded superior OHS (p = 0.013), UCLA (p = 0.008), and EuroQol visual analogue scores (p = 0.009). After nine years, patients with BHRs remained more active and had a lower rate of revision than those with hybrid THRs. Both groups demonstrated progressive radiological changes at medium-term follow-up.
This prospective study compares the outcome of
157 hydroxyapatite (HA)-coated tibial components with 164 cemented
components in the ROCC Rotating Platform total knee replacement
in 291 patients. The mean follow-up was 7.6 years (5.2 to 11). There
were two revisions for loosening: one for an HA-coated and one for
a cemented tibial component. Radiological evaluation demonstrated
no radiolucent lines with the HA-coated femoral components. A total
of three HA-coated tibial components exhibited radiolucent lines
at three months post-operatively and these disappeared after three
further months of protected weight-bearing. With HA-coated components
the operating time was shorter (p <
0.006) and the radiological
assessment of the tibial interface was more stable (p <
0.01).
Using revision for aseptic loosening of the tibial component as
the end point, the survival rates at nine years was identical for
both groups at 99.1%. Our results suggest that HA-coated components perform at least
as well as the same design with cemented components and compare
favourably with those of series describing cemented or porous-coated
knee replacements, suggesting that fixation of both components with
hydroxyapatite is a reliable option in primary total knee replacement.
The use of passive stretching of the elbow after
arthrolysis is controversial. We report the results of open arthrolysis in
81 patients. Prospectively collected outcome data with a minimum
follow-up of one year were analysed. All patients had sustained
an intra-articular fracture initially and all procedures were performed
by the same surgeon under continuous brachial plexus block anaesthesia
and with continuous passive movement (CPM) used post-operatively
for two to three days. CPM was used to maintain the movement achieved
during surgery and passive stretching was not used at any time.
A senior physiotherapist assessed all the patients at regular intervals.
The mean range of movement (ROM) improved from 69° to 109° and the
function and pain of the upper limb improved from 32 to 16 and from
20 to 10, as assessed by the Disabilities of the Arm Shoulder and
Hand score and a visual analogue scale, respectively. The greatest
improvement was obtained in the stiffest elbows: nine patients with
a pre-operative ROM <
30° achieved a mean post-operative ROM
of 92° (55° to 125°). This study demonstrates that in patients with
a stiff elbow after injury, good results may be obtained after open
elbow arthrolysis without using passive stretching during rehabilitation.
This prospective study describes the outcome of the first 1000 phase 3 Oxford medial unicompartmental knee replacements (UKRs) implanted using a minimally invasive surgical approach for the recommended indications by two surgeons and followed up independently. The mean follow-up was 5.6 years (1 to 11) with 547 knees having a minimum follow-up of five years. At five years their mean Oxford knee score was 41.3 ( The incidence of implant-related re-operations was 2.9%; of these 29 re-operations two were revisions requiring revision knee replacement components with stems and wedges, 17 were conversions to a primary total knee replacement, six were open reductions for dislocation of the bearing, three were secondary lateral UKRs and one was revision of a tibial component. The most common reason for further surgical intervention was progression of arthritis in the lateral compartment (0.9%), followed by dislocation of the bearing (0.6%) and revision for unexplained pain (0.6%). If all implant-related re-operations are considered failures, the ten-year survival rate was 96% (95% confidence interval, 92.5 to 99.5). If only revisions requiring revision components are considered failures the ten-year survival rate is 99.8% (confidence interval 99 to 100). This is the largest published series of UKRs implanted through a minimally invasive surgical approach and with ten-year survival data. The survival rates are similar to those obtained with a standard open approach whereas the function is better. This demonstrates the effectiveness and safety of a minimally invasive surgical approach for implanting the Oxford UKR.
We investigated the stability of seven Schatzker type II fractures of the lateral tibial plateau treated by subchondral screws and a buttress plate followed by immediate partial weight-bearing. In order to assess the stability of the fracture, weight-bearing inducible displacements of the fracture fragments and their migration over a one-year period were measured by differentially loaded radiostereometric analysis and standard radiostereometric analysis, respectively. The mean inducible craniocaudal fracture fragment displacements measured −0.30 mm (−0.73 to 0.02) at two weeks and 0.00 mm (−0.12 to 0.15) at 52 weeks. All inducible displacements were elastic in nature under all loads at each examination during follow-up. At one year, the mean craniocaudal migration of the fracture fragments was −0.34 mm (−1.64 to 1.51). Using radiostereometric methods, this case series has shown that in the Schatzker type II fractures investigated, internal fixation with subchondral screws and a buttress plate provided adequate stability to allow immediate post-operative partial weight-bearing, without harmful consequences.
There is little information available at present regarding the mechanisms of failure of modern metallic radial head implants. Between 1998 and 2008, 44 consecutive patients (47 elbows) underwent removal of a failed metallic radial head replacement. In 13 patients (13 elbows) the initial operation had been undertaken within one week of a fracture of the radial head, at one to six weeks in seven patients (seven elbows) and more than six weeks (mean of 2.5 years (2 to 65 months)) in 22 patients (25 elbows). In the remaining two elbows the replacement was inserted for non-traumatic reasons. The most common indication for further surgery was painful loosening (31 elbows). Revision was undertaken for stiffness in 18 elbows, instability in nine, and deep infection in two. There were signs of over-lengthening of the radius in 11 elbows. Degenerative changes were found in all but one. Only three loose implants had been fixed with cement. Instability was not identified in any of the bipolar implants.
Surgical dislocation of the hip in the treatment of acetabular fractures allows the femoral head to be safely displaced from the acetabulum. This permits full intra-articular acetabular and femoral inspection for the evaluation and potential treatment of cartilage lesions of the labrum and femoral head, reduction of the fracture under direct vision and avoidance of intra-articular penetration with hardware. We report 60 patients with selected types of acetabular fracture who were treated using this approach. Six were lost to follow-up and the remaining 54 were available for clinical and radiological review at a mean follow-up of 4.4 years (2 to 9). Substantial damage to the intra-articular cartilage was found in the anteromedial portion of the femoral head and the posterosuperior aspect of the acetabulum. Labral lesions were predominantly seen in the posterior acetabular area. Anatomical reduction was achieved in 50 hips (93%) which was considerably higher than that seen in previous reports. There were no cases of avascular necrosis. Four patients subsequently required total hip replacement. Good or excellent results were achieved in 44 hips (81.5%). The cumulative eight-year survivorship was 89.0% (95% confidence interval 84.5 to 94.1). Significant predictors of poor outcome were involvement of the acetabular dome and lesions of the femoral cartilage greater than grade 2. The functional mid-term results were better than those of previous reports. Surgical dislocation of the hip allows accurate reduction and a predictable mid-term outcome in the management of these difficult injuries without the risk of the development of avascular necrosis.
In a randomised trial involving 598 patients
with 600 trochanteric fractures of the hip, the fractures were treated with
either a sliding hip screw (n = 300) or a Targon PF intramedullary
nail (n = 300). The mean age of the patients was 82 years (26 to
104). All surviving patients were reviewed at one year with functional
outcome assessed by a research nurse blinded to the treatment used.
The intramedullary nail was found to have a slightly increased mean
operative time (46 minutes ( In summary, both implants produced comparable results but there
was a tendency to better return of mobility for those treated with
the intramedullary nail.
Over recent years hip arthroscopic surgery has
evolved into one of the most rapidly expanding fields in orthopaedic surgery.
Complications are largely transient and incidences between 0.5%
and 6.4% have been reported. However, major complications can and
do occur. This article analyses the reported complications and makes recommendations
based on the literature review and personal experience on how to
minimise them.
Impingement syndrome in the shoulder has generally been considered to be a clinical condition of mechanical origin. However, anomalies exist between the pathology in the subacromial space and the degree of pain experienced. These may be explained by variations in the processing of nociceptive inputs between different patients. We investigated the evidence for augmented pain transmission (central sensitisation) in patients with impingement, and the relationship between pre-operative central sensitisation and the outcomes following arthroscopic subacromial decompression. We recruited 17 patients with unilateral impingement of the shoulder and 17 age- and gender-matched controls, all of whom underwent quantitative sensory testing to detect thresholds for mechanical stimuli, distinctions between sharp and blunt punctate stimuli, and heat pain. Additionally Oxford shoulder scores to assess pain and function, and PainDETECT questionnaires to identify ‘neuropathic’ and referred symptoms were completed. Patients completed these questionnaires pre-operatively and three months post-operatively. A significant proportion of patients awaiting subacromial decompression had referred pain radiating down the arm and had significant hyperalgesia to punctate stimulus of the skin compared with controls (unpaired The presence of either hyperalgesia or referred pain pre-operatively resulted in a significantly worse outcome from decompression three months after surgery (unpaired These observations confirm the presence of central sensitisation in a proportion of patients with shoulder pain associated with impingement. Also, if patients had relatively high levels of central sensitisation pre-operatively, as indicated by higher levels of punctate hyperalgesia and/or referred pain, the outcome three months after subacromial decompression was significantly worse.
We obtained information from the Elective Orthopaedic
Centre on 1523 patients with baseline and six-month Oxford hip scores
(OHS) after undergoing primary hip replacement (THR) and 1784 patients
with Oxford knee scores (OKS) for primary knee replacement (TKR)
who completed a six-month satisfaction questionnaire. Receiver operating characteristic curves identified an absolute
change in OHS of 14 points or more as the point that discriminates
best between patients’ satisfaction levels and an 11-point change
for the OKS. Satisfaction is highest (97.6%) in patients with an
absolute change in OHS of 14 points or more, compared with lower
levels of satisfaction (81.8%) below this threshold. Similarly,
an 11-point absolute change in OKS was associated with 95.4% satisfaction
compared with 76.5% below this threshold. For the six-month OHS
a score of 35 points or more distinguished patients with the highest
satisfaction level, and for the six-month OKS 30 points or more identified
the highest level of satisfaction. The thresholds varied according
to patients’ pre-operative score, where those with severe pre-operative
pain/function required a lower six-month score to achieve the highest
levels of satisfaction. Our data suggest that the choice of a six-month follow-up to
assess patient-reported outcomes of THR/TKR is acceptable. The thresholds
help to differentiate between patients with different levels of
satisfaction, but external validation will be required prior to
general implementation in clinical practice.
The most frequent cause of failure after total
hip replacement in all reported arthroplasty registries is peri-prosthetic
osteolysis. Osteolysis is an active biological process initiated
in response to wear debris. The eventual response to this process
is the activation of macrophages and loss of bone. Activation of macrophages initiates a complex biological cascade
resulting in the final common pathway of an increase in osteolytic
activity. The biological initiators, mechanisms for and regulation
of this process are beginning to be understood. This article explores current
concepts in the causes of, and underlying biological mechanism resulting
in peri-prosthetic osteolysis, reviewing the current basic science
and clinical literature surrounding the topic.
Between April 2004 and July 2007, we performed 241 primary total knee replacements in 204 patients using the e.motion posterior cruciate-retaining, multidirectional mobile-bearing prosthesis. Of these, 100 were carried out using an image-free navigation system, and the remaining 141 with the conventional technique. We conducted a retrospective study from the prospectively collected data of these patients to assess the early results of this new mobile-bearing design. At a mean follow-up of 49 months (32 to 71), 18 knees (7.5%) had mechanical complications of which 13 required revision. Three of these had a peri-prosthetic fracture, and were removed from the study. The indication for revision in the remaining ten was loosening of the femoral component in two, tibiofemoral dislocation in three, disassociation of the polyethylene liner in four, and a broken polyethyene liner in one. There were eight further mechanically unstable knees which presented with recurrent disassociation of the polyethylene liner. There was no significant difference in the incidence of mechanical instability between the navigation-assisted procedures (8 of 99, 8.1%) and the conventionally implanted knees (10 of 139, 7.2%). In our view, the relatively high rate of mechanical complications and revision within 30 months precludes the further use of new design of knee replacement.
Peripheral nerve injury is an uncommon but serious
complication of hip surgery that can adversely affect the outcome.
Several studies have described the use of electromyography and intra-operative
sensory evoked potentials for early warning of nerve injury. We
assessed the results of multimodal intra-operative monitoring during
complex hip surgery. We retrospectively analysed data collected
between 2001 and 2010 from 69 patients who underwent complex hip
surgery by a single surgeon using multimodal intra-operative monitoring
from a total pool of 7894 patients who underwent hip surgery during
this period. In 24 (35%) procedures the surgeon was alerted to a
possible lesion to the sciatic and/or femoral nerve. Alerts were
observed most frequently during peri-acetabular osteotomy. The surgeon
adapted his approach based on interpretation of the neurophysiological changes.
From 69 monitored surgical procedures, there was only one true positive
case of post-operative nerve injury. There were no false positives
or false negatives, and the remaining 68 cases were all true negative.
The sensitivity for predicting post-operative nerve injury was 100%
and the specificity 100%. We conclude that it is possible and appropriate
to use this method during complex hip surgery and it is effective
for alerting the surgeon to the possibility of nerve injury.
Symptomatic and asymptomatic deep-vein thrombosis
(DVT) is a common complication of knee replacement, with an incidence
of up to 85% in the absence of prophylaxis. National guidelines
for thromboprophylaxis in knee replacement are derived from total
knee replacement (TKR) data. No guidelines exist specific to unicompartmental knee
replacement (UKR). We investigated whether the type of knee arthroplasty
(TKR or UKR) was related to the incidence of DVT and discuss the
applicability of existing national guidelines for prophylaxis following
UKR. Data were collected prospectively on 3449 knee replacements,
including procedure type, tourniquet time, surgeon, patient age,
use of drains and gender. These variables were related to the incidence
of symptomatic DVT. The overall DVT rate was 1.6%. The only variable that had an
association with DVT was operation type, with TKR having a higher
incidence than UKR (2.2% TKR and UKR patients have different risk profiles for symptomatic
DVT. The risk-benefit ratio for TKR that has been used to produce
national guidelines may not be applicable to UKR. Further research
is required to establish the most appropriate form of prophylaxis
for UKR.
Traditional techniques for the insertion of femoral stems in arthroplasty of the hip in osteopetrosis carry a considerable risk of penetration of the femoral cortex and intra-operative fractures, due to obliteration of the intramedullary cavity and greatly increased stiffness and brittleness of the bone. In order to reduce the risk of such complications we manufactured a customised stem and a computer-based guiding device for the preparation of a cavity within the proximal femur. This system was used successfully in three hips in two patients. We describe the system and the operative technique.
This study reports the mid-term results of a large-bearing hybrid metal-on-metal total hip replacement in 199 hips (185 patients) with a mean follow-up of 62 months (32 to 83). Two patients died of unrelated causes and 13 were lost to follow-up. In all, 17 hips (8.5%) have undergone revision, and a further 14 are awaiting surgery. All revisions were symptomatic. Of the revision cases, 14 hips showed evidence of adverse reactions to metal debris. The patients revised or awaiting revision had significantly higher whole blood cobalt ion levels (p = 0.001), but no significant difference in acetabular component size or position compared with the unrevised patients. Wear analysis (n = 5) showed increased wear at the trunnion-head interface, normal levels of wear at the articulating surfaces and evidence of corrosion on the surface of the stem. The cumulative survival rate, with revision for any reason, was 92.4% (95% confidence interval 87.4 to 95.4) at five years. Including those awaiting surgery, the revision rate would be 15.1% with a cumulative survival at five years of 89.6% (95% confidence interval 83.9 to 93.4). This hybrid metal-on-metal total hip replacement series has shown an unacceptably high rate of failure, with evidence of high wear at the trunnion-head interface and passive corrosion of the stem surface. This raises concerns about the use of large heads on conventional 12/14 tapers.