Osteoarthritis results in changes in the dimensions
of the glenoid. This study aimed to assess the size and radius of curvature
of arthritic glenoids. A total of 145 CT scans were analysed, performed
as part of routine pre-operative assessment before total shoulder
replacement in 91 women and 54 men. Only patients with primary osteoarthritis and
a concentric glenoid were included in the study. The CT scans underwent
three-dimensional (3D) reconstruction and were analysed using dedicated
computer software. The measurements consisted of maximum superoinferior height,
anteroposterior width and a best-fit sphere radius of curvature
of the glenoid. The mean height was 40.2 mm (. sd. 4.9), the mean width
was 29 mm (. sd. 4.3) and the mean
The August 2013 Trauma Roundup. 360 . looks at: reverse oblique fractures do better with a cephalomedullary device; locking screws confer no advantage in tibial plateau fractures; it’s all about the
Aims. The aim of this study was to analyze the association between the shape of the distal radius sigmoid notch and triangular fibrocartilage complex (TFCC) foveal tear. Methods. Between 2013 and 2018, patients were retrospectively recruited in two different groups. The patient group comprised individuals who underwent arthroscopic transosseous TFCC foveal repair for foveal tear of the wrist. The control group comprised individuals presenting with various diseases around wrist not affecting the TFCC. The study recruited 176 patients (58 patients, 118 controls). The sigmoid notch shape was classified into four types (flat-face, C-, S-, and ski-slope types) and three radiological parameters related to the sigmoid notch (namely, the
The survival of humeral hemiarthroplasties in patients with relatively intact glenoid cartilage could theoretically be extended by minimizing the associated postoperative glenoid erosion. Ceramic has gained attention as an alternative to metal as a material for hemiarthroplasties because of its superior tribological properties. The aim of this study was to assess the in vitro wear performance of ceramic and metal humeral hemiarthroplasties on natural glenoids. Intact right cadaveric shoulders from donors aged between 50 and 65 years were assigned to a ceramic group (n = 8, four male cadavers) and a metal group (n = 9, four male cadavers). A dedicated shoulder wear simulator was used to simulate daily activity by replicating the relevant joint motion and loading profiles. During testing, the joint was kept lubricated with diluted calf serum at room temperature. Each test of wear was performed for 500,000 cycles at 1.2 Hz. At intervals of 125,000 cycles, micro-CT scans of each glenoid were taken to characterize and quantify glenoid wear by calculating the change in the thickness of its articular cartilage.Aims
Methods
Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented femoral stem design on the risk of PFF. Cite this article:
Focal knee arthroplasty is an attractive alternative to knee arthroplasty for young patients because it allows preservation of a large amount of bone for potential revisions. However, the mechanical behaviour of cartilage has not yet been investigated because it is challenging to evaluate in vivo contact areas, pressure, and deformations from metal implants. Therefore, this study aimed to determine the contact pressure in the tibiofemoral joint with a focal knee arthroplasty using a finite element model. The mechanical behaviour of the cartilage surrounding a metal implant was evaluated using finite element analysis. We modelled focal knee arthroplasty with placement flush, 0.5 mm deep, or protruding 0.5 mm with regard to the level of the surrounding cartilage. We compared contact stress and pressure for bone, implant, and cartilage under static loading conditions.Aims
Methods
The Vantage Total Ankle System is a fourth-generation low-profile fixed-bearing implant that has been available since 2016. We aimed to describe our early experience with this implant. This is a single-centre retrospective review of patients who underwent primary total ankle arthroplasty (TAA) with a Vantage implant between November 2017 and February 2020, with a minimum of two years’ follow-up. Four surgeons contributed patients. The primary outcome was reoperation and revision rate of the Vantage implant at two years. Secondary outcomes included radiological alignment, peri-implant complications, and pre- and postoperative patient-reported outcomes.Aims
Methods
The aims were to assess whether joint-specific outcome after total knee arthroplasty (TKA) was influenced by implant design over a 12-year follow-up period, and whether patient-related factors were associated with loss to follow-up and mortality risk. Long-term follow-up of a randomized controlled trial was undertaken. A total of 212 patients were allocated a Triathlon or a Kinemax TKA. Patients were assessed preoperatively, and one, three, eight, and 12 years postoperatively using the Oxford Knee Score (OKS). Reasons for patient lost to follow-up, mortality, and revision were recorded.Aims
Methods
Bone defects are frequently observed in anterior shoulder instability. Over the last decade, knowledge of the association of bone loss with increased failure rates of soft-tissue repair has shifted the surgical management of chronic shoulder instability. On the glenoid side, there is no controversy about the critical glenoid bone loss being 20%. However, poor outcomes have been described even with a subcritical glenoid bone defect as low as 13.5%. On the humeral side, the Hill-Sachs lesion should be evaluated concomitantly with the glenoid defect as the two sides of the same bipolar lesion which interact in the instability process, as described by the glenoid track concept. We advocate adding remplissage to every Bankart repair in patients with a Hill-Sachs lesion, regardless of the glenoid bone loss. When critical or subcritical glenoid bone loss occurs in active patients (> 15%) or bipolar off-track lesions, we should consider anterior glenoid bone reconstructions. The techniques have evolved significantly over the last two decades, moving from open procedures to arthroscopic, and from screw fixation to metal-free fixation. The new arthroscopic techniques of glenoid bone reconstruction procedures allow precise positioning of the graft, identification, and treatment of concomitant injuries with low morbidity and faster recovery. Given the problems associated with bone resorption and metal hardware protrusion, the new metal-free techniques for Latarjet or free bone block procedures seem a good solution to avoid these complications, although no long-term data are yet available. Cite this article:
The purpose of this study was to report bone adaptive changes after anatomical total shoulder arthroplasty (TSA) using a standard-length hydroxyapatite (HA)-coated humeral component, and to report on a computer-based analysis of radiographs to determine changes in peri-implant bone density objectively. A total of 44 TSAs, performed between 2011 and 2014 using a cementless standard-length humeral component proximally coated with HA, were included. There were 23 males and 21 females with a mean age of 65 years (17 to 65). All shoulders had good quality radiographs at six weeks and five years postoperatively. Three observers graded bone adaptive changes. All radiographs were uploaded into a commercially available photographic software program. The grey value density of humeral radiological areas was corrected to the grey value density of the humeral component and compared over time.Aims
Methods
Surgeons commonly resect additional distal femur during primary total knee arthroplasty (TKA) to correct a flexion contracture, which leads to femoral joint line elevation. There is a paucity of data describing the effect of joint line elevation on mid-flexion stability and knee kinematics. Thus, the goal of this study was to quantify the effect of joint line elevation on mid-flexion laxity. Six computational knee models with cadaver-specific capsular and collateral ligament properties were implanted with a posterior-stabilized (PS) TKA. A 10° flexion contracture was created in each model to simulate a capsular contracture. Distal femoral resections of + 2 mm and + 4 mm were then simulated for each knee. The knee models were then extended under a standard moment. Subsequently, varus and valgus moments of 10 Nm were applied as the knee was flexed from 0° to 90° at baseline and repeated after each of the two distal resections. Coronal laxity (the sum of varus and valgus angulation with respective maximum moments) was measured throughout flexion.Aims
Methods
The aims of this study were to evaluate wear on the surface of cobalt-chromium (CoCr) femoral components used in total knee arthroplasty (TKA) and compare the wear of these components with that of ceramic femoral components. Optical profilometry was used to evaluate surface roughness and to examine the features created by the wear process in a knee wear simulator. We developed a method of measuring surface changes on five CoCr femoral components and quantifying the loss of material from the articular surface during the wear process. We also examined the articular surface of three ceramic femoral components from a previous test for evidence of surface damage, and compared it with that of CoCr components.Aims
Methods
The bony shoulder stability ratio (BSSR) allows for quantification of the bony stabilisers Four polyethylene balls (radii: 19.1 mm to 38.1 mm) were used to mould four fitting sockets in four different depths (3.2 mm to 19.1mm). The SR was measured in biomechanical congruent and incongruent experimental series. The experimental SR of a congruent system was compared with the calculated SR based on the BSSR approach. Differences in SR between congruent and incongruent experimental conditions were quantified. Finally, the experimental SR was compared with either calculated SR based on the socket concavity or plastic ball radius.Objectives
Methods
Restoring the pre-morbid anatomy of the proximal humerus is a
goal of anatomical shoulder arthroplasty, but reliance is placed
on the surgeon’s experience and on anatomical estimations. The purpose
of this study was to present a novel method, ‘Statistical Shape
Modelling’, which accurately predicts the pre-morbid proximal humeral anatomy
and calculates the 3D geometric parameters needed to restore normal
anatomy in patients with severe degenerative osteoarthritis or a
fracture of the proximal humerus. From a database of 57 humeral CT scans 3D humeral reconstructions
were manually created. The reconstructions were used to construct
a statistical shape model (SSM), which was then tested on a second
set of 52 scans. For each humerus in the second set, 3D reconstructions
of four diaphyseal segments of varying lengths were created. These
reconstructions were chosen to mimic severe osteoarthritis, a fracture
of the surgical neck of the humerus and a proximal humeral fracture
with diaphyseal extension. The SSM was then applied to the diaphyseal
segments to see how well it predicted proximal morphology, using
the actual proximal humeral morphology for comparison.Aims
Materials and Methods
Aims
Patients and Methods
The results of kinematic total knee arthroplasty (KTKA) have been reported in terms of limb and component alignment parameters but not in terms of gap laxities and differentials. In kinematic alignment (KA), balance should reflect the asymmetrical balance of the normal knee, not the classic rectangular flexion and extension gaps sought with gap-balanced mechanical axis total knee arthroplasty (MATKA). This paper aims to address the following questions: 1) what factors determine coronal joint congruence as measured on standing radiographs?; 2) is flexion gap asymmetry produced with KA?; 3) does lateral flexion gap laxity affect outcomes?; 4) is lateral flexion gap laxity associated with lateral extension gap laxity?; and 5) can consistent ligament balance be produced without releases? A total of 192 KTKAs completed by a single surgeon using a computer-assisted technique were followed for a mean of 3.5 years (2 to 5). There were 116 male patients (60%) and 76 female patients (40%) with a mean age of 65 years (48 to 88). Outcome measures included intraoperative gap laxity measurements and component positions, as well as joint angles from postoperative three-foot standing radiographs. Patient-reported outcome measures (PROMs) were analyzed in terms of alignment and balance: EuroQol (EQ)-5D visual analogue scale (VAS), Knee Injury and Osteoarthritis Outcome Score (KOOS), KOOS Joint Replacement (JR), and Oxford Knee Score (OKS).Aims
Patients and Methods
The Walch Type C dysplastic glenoid is characterized by excessive
retroversion. This anatomical study describes its morphology. A total of 29 shoulders with a dysplastic glenoid were analyzed.
CT was used to measure retroversion, inclination, height, width,
radius-of-curvature, surface area, depth, subluxation of the humeral
head and the Goutallier classification of fatty infiltration. The
severity of dysplasia and deficiency of the posterior rim of the
glenoid were recorded.Aims
Patients and Methods
Controversy about the use of an anatomical total shoulder arthroplasty
(aTSA) in young arthritic patients relates to which is the ideal
form of fixation for the glenoid component: cemented or cementless.
This study aimed to evaluate implant survival of aTSA when used
in patients aged < 60 years with primary glenohumeral osteoarthritis (OA),
and to compare the survival of cemented all-polyethylene and cementless
metal-backed glenoid components. A total of 69 consecutive aTSAs were performed in 67 patients
aged < 60 years with primary glenohumeral OA. Their mean age
at the time of surgery was 54 years (35 to 60). Of these aTSAs,
46 were undertaken using a cemented polyethylene component and 23
were undertaken using a cementless metal-backed component. The age, gender,
preoperative function, mobility, premorbid glenoid erosion, and
length of follow-up were comparable in the two groups. The patients
were reviewed clinically and radiographically at a mean of 10.3
years (5 to 12, Aims
Materials and Methods
Total shoulder replacement is a successful procedure for degenerative or some inflammatory diseases of the shoulder. However, fixation of the glenoid seems to be the main weakness with a high rate of loosening. The results using all-polyethylene components have been better than those using metal-backed components. We describe our experience with 35 consecutive total shoulder replacements using a new metal-backed glenoid component with a mean follow-up of 75.4 months (48 to 154). Our implant differs from others because of its mechanism of fixation. It has a convex metal-backed bone interface and the main stabilising factor is a large hollow central peg. The patients were evaulated with standard radiographs and with the Constant Score, the Simple Shoulder Test and a visual analogue scale. All the scores improved and there was no loosening, no polyethylene-glenoid disassembly and no other implant-related complications. We conclude that a metal-backed glenoid component is a good option in total shoulder replacement with no worse results than of those using a cemented all-polyethylene prosthesis.
Posterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect of PCO and PTS on cruciate retaining TKA. We generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions.Objectives
Methods
There are theoretical and practical advantages to modular rather than monoblock designs of prostheses for shoulder arthroplasty, but there are no reported studies which specifically compare the clinical and radiological results of their use. We have compared the results of unconstrained total shoulder arthroplasty for osteoarthritis using both types of implant. The monoblock design was used between 1992 and 1995 and the modular design after 1995. Both had cemented all-polyethylene glenoids, the monoblock with matched and the modular with mismatched radii of curvature. There were 34 consecutive shoulders in each group with a mean follow-up of 6.1 years in the first and 5.2 years in the second. There were no significant differences in improvement of pain scores, active elevation, external rotation, internal rotation, patient satisfaction, or the Neer ratings between the two groups. Two of 28 glenoid components in the first group and six of 30 in the second met the criteria for being radiologically at risk for loosening (p = 0.25). There were no significant differences in clinical outcome or radiological changes between the first- and second-generation designs of implant for shoulder arthroplasty.
The aim of this paper is to review the evidence relating to the
anatomy of the proximal femur, the geometry of the fracture and
the characteristics of implants and methods of fixation of intertrochanteric
fractures of the hip. Relevant papers were identified from appropriate clinical databases
and a narrative review was undertaken.Aims
Materials and Methods
Our aim was to examine the clinical and radiographic outcomes
in 257 consecutive Oxford unicompartmental knee arthroplasties (OUKAs)
(238 patients), five years post-operatively. A retrospective evaluation was undertaken of patients treated
between April 2008 and October 2010 in a regional centre by two
non-designing surgeons with no previous experience of UKAs. The
Oxford Knee Scores (OKSs) were recorded and fluoroscopically aligned
radiographs were assessed post-operatively at one and five years.Aims
Patients and Methods
To determine the effect of a change in design of a cementless
ceramic acetabular component in fixation and clinical outcome after
total hip arthroplasty We compared 342 hips (302 patients) operated between 1999 and
2005 with a relatively smooth hydroxyapatite coated acetabular component
(group 1), and 337 hips (310 patients) operated between 2006 and
2011 using a similar acetabular component with a macrotexture on
the entire outer surface of the component (group 2). The mean age of
the patients was 53.5 (14 to 70) in group 1 and 53.0 (15 to 70)
in group 2. The mean follow-up was 12.7 years (10 to 17) for group
1 and 7.2 years (4 to 10) for group 2.Aims
Patients and Methods
Patient-specific glenoid guides (PSGs) claim an improvement in
accuracy and reproducibility of the positioning of components in
total shoulder arthroplasty (TSA). The results have not yet been
confirmed in a prospective clinical trial. Our aim was to assess
whether the use of PSGs in patients with osteoarthritis of the shoulder
would allow accurate and reliable implantation of the glenoid component. A total of 17 patients (three men and 14 women) with a mean age
of 71 years (53 to 81) awaiting TSA were enrolled in the study.
Pre- and post-operative version and inclination of the glenoid were
measured on CT scans, using 3D planning automatic software. During
surgery, a congruent 3D-printed PSG was applied onto the glenoid
surface, thus determining the entry point and orientation of the
central guide wire used for reaming the glenoid and the introduction
of the component. Manual segmentation was performed on post-operative
CT scans to compare the planned and the actual position of the entry
point (mm) and orientation of the component (°).Aims
Patients and Methods
The aim of this study was to investigate differences in pain,
range of movement function and satisfaction at three months and
one year after total knee arthroplasty (TKA) in patients with an
oblique pattern of kinematic graph of the knee and those with a
varus pattern. A total of 91 patients who underwent TKA were included in this
retrospective study. Patients (59 women and 32 men with mean age
of 68.7 years; 38.6 to 88.4) were grouped according to kinematic
graphs which were generated during navigated TKA and the outcomes
between the groups were compared.Aims
Patients and Methods
Up to 40% of unicompartmental knee arthroplasty (UKA) revisions are performed for unexplained pain which may be caused by elevated proximal tibial bone strain. This study investigates the effect of tibial component metal backing and polyethylene thickness on bone strain in a cemented fixed-bearing medial UKA using a finite element model (FEM) validated experimentally by digital image correlation (DIC) and acoustic emission (AE). A total of ten composite tibias implanted with all-polyethylene (AP) and metal-backed (MB) tibial components were loaded to 2500 N. Cortical strain was measured using DIC and cancellous microdamage using AE. FEMs were created and validated and polyethylene thickness varied from 6 mm to 10 mm. The volume of cancellous bone exposed to < -3000 µε (pathological loading) and < -7000 µε (yield point) minimum principal (compressive) microstrain and > 3000 µε and > 7000 µε maximum principal (tensile) microstrain was computed.Objectives
Materials and Methods
The Advance Medial-Pivot total knee arthroplasty (TKA) was designed
to reflect contemporary data regarding the kinematics of the knee.
We wished to examine the long-term results obtained with this prosthesis
by extending a previous evaluation. We retrospectively evaluated prospectively collected data from
225 consecutive patients (41 men and 184 women; mean age at surgery
71 years, 52 to 84) who underwent 284 TKAs with a mean follow-up
of 13.4 years (11 to 15). Implant failure, complication rate, clinical (both
subjective and objective) and radiological outcome were assessed.
Pre- and post-operative clinical and radiographic data were available
at regular intervals for all patients. A total of ten patients (4.4%;
ten TKAs) were lost to follow-up.Aims
Patients and Methods
To assess the extent of osteointegration in two designs of shoulder
resurfacing implants. Bony integration to the Copeland cylindrical
central stem design and the Epoca RH conical-crown design were compared. Implants retrieved from six patients in each group were pair-matched.
Mean time to revision surgery of Copeland implants was 37 months
(standard deviation (Aims
Patients and Methods
Slipped capital femoral epiphysis (SCFE) may
lead to symptomatic femoroacetabular impingement (FAI). We report our
experience of arthroscopic treatment, including osteochondroplasty,
for the sequelae of SCFE. Data were prospectively collected on patients undergoing arthroscopy
of the hip for the sequelae of SCFE between March 2007 and February
2013, including demographic data, radiological assessment of the
deformity and other factors that may influence outcome, such as
the presence of established avascular necrosis. Patients completed
the modified Harris hip score (mHHS) and the non-arthritic hip score
(NAHS) before and after surgery. In total, 18 patients with a mean age of 19 years (13 to 42),
were included in the study. All patients presented with pain in
the hip and mechanical symptoms, and had evidence of FAI (cam or
mixed impingement) on plain radiographs. The patients underwent arthroscopic osteoplasty of the femoral
neck. The mean follow-up was 29 months (23 to 56). The mean mHHS and NAHS scores improved from 56.2 (27.5 to 100.1)
and 52.1 (12.5 to 97.5) pre-operatively to 75.1 (33.8 to 96.8, p
= 0.01) and 73.6 (18.8 to 100, p = 0.02) at final follow-up, respectively.
Linear regression analysis demonstrated a significant association
between poorer outcome scores and increased time to surgery following SCFE
(p <
0.05 for all parameters except baseline MHHS). Symptomatic FAI following (SCFE) may be addressed using arthroscopic
techniques, and should be treated promptly to minimise progressive
functional impairment and chondrolabral degeneration. Take home message: Arthroscopy of the hip can be used to treat
femoroacetabular impingement successfully following SCFE. However,
this should be performed promptly after presentation in order to
prevent irreversible progression and poorer clinical outcomes. Cite this article:
The lateral compartment is predominantly affected
in approximately 10% of patients with osteoarthritis of the knee. The
anatomy, kinematics and loading during movement differ considerably
between medial and lateral compartments of the knee. This in the
main explains the relative protection of the lateral compartment
compared with the medial compartment in the development of osteoarthritis.
The aetiology of lateral compartment osteoarthritis can be idiopathic,
usually affecting the femur, or secondary to trauma commonly affecting
the tibia. Surgical management of lateral compartment osteoarthritis
can include osteotomy, unicompartmental knee replacement and total
knee replacement. This review discusses the biomechanics, pathogenesis
and development of lateral compartment osteoarthritis and its management. Cite this article:
We evaluated clinical and radiographic outcomes of total shoulder
arthroplasty (TSA) using the second-generation Trabecular Metal
(TM) Glenoid component. The first generation component was withdrawn
in 2005 after a series of failures were reported. Between 2009 and
2012, 40 consecutive patients with unilateral TSA using the second-generation
component were enrolled in this clinical study. The mean age of
the patients was 63.8 years (40 to 75) and the mean follow-up was
38 months (24 to 42). Patients were evaluated using the Constant score (CS), the American
Shoulder and Elbow Surgeons (ASES) score and routine radiographs.Aims
Methods
In a prospective study between 2000 and 2005, 22 patients with primary osteoarthritis of the shoulder had a total shoulder arthroplasty with a standard five-pegged glenoid component, 12 with non-offset humeral head and ten with offset humeral head components. Over a period of 24 months the relative movement of the glenoid component with respect to the scapula was measured using radiostereometric analysis. Nine glenoids needed reaming for erosion. There was a significant increase in rotation about all three axes with time (p <
0.001), the largest occurring about the longitudinal axis (anteversion-retroversion), with mean values of 3.8° and 1.9° for the non-offset and offset humeral head eroded subgroups, respectively. There was also a significant difference in rotation about the anteversion-retroversion axis (p = 0.01) and the varus-valgus (p <
0.001) z-axis between the two groups. The offset humeral head group reached a plateau at early follow-up with rotation about the z-axis, whereas the mean of the non-offset humeral head group at 24 months was three times greater than that of the offset group accounting for the highly significant difference between them.
The Oxford Unicompartmental Knee replacement (UKR) was introduced as a design to reduce polyethylene wear. There has been one previous retrieval study involving this implant, which reported very low rates of wear in some specimens but abnormal patterns of wear in others. There has been no further investigation of these abnormal patterns. The bearings were retrieved from 47 patients who had received a medial Oxford UKR for anteromedial osteoarthritis of the knee. None had been studied previously. The mean time to revision was 8.4 years ( These results show that very low rates of polyethylene wear are possible if the device functions normally. However, if the bearing displays suboptimal function (extra-articular, intra-articular impingement or incongruous articulation) the rates of wear increase significantly.
Total knee arthroplasty (TKA) is an established
and successful procedure. However, the design of prostheses continues
to be modified in an attempt to optimise the functional outcome
of the patient. The aim of this study was to determine if patient outcome after
TKA was influenced by the design of the prosthesis used. A total of 212 patients (mean age 69; 43 to 92; 131 female (62%),
81 male (32%)) were enrolled in a single centre double-blind trial
and randomised to receive either a Kinemax (group 1) or a Triathlon
(group 2) TKA. Patients were assessed pre-operatively, at six weeks, six months,
one year and three years after surgery. The outcome assessments
used were the Oxford Knee Score; range of movement; pain numerical
rating scales; lower limb power output; timed functional assessment
battery and a satisfaction survey. Data were assessed incorporating
change over all assessment time points, using repeated measures
analysis of variance longitudinal mixed models. Implant group 2
showed a significantly greater range of movement (p = 0.009), greater
lower limb power output (p = 0.026) and reduced report of ‘worst
daily pain’ (p = 0.003) over the three years of follow-up. Differences
in Oxford Knee Score (p = 0.09), report of ‘average daily pain’
(p = 0.57) and timed functional performance tasks (p = 0.23) did
not reach statistical significance. Satisfaction with outcome was
significantly better in group 2 (p = 0.001). These results suggest that patient outcome after TKA can be influenced
by the prosthesis used. Cite this article:
We report the clinical and radiological outcome
of subcapital osteotomy of the femoral neck in the management of symptomatic
femoroacetabular impingement (FAI) resulting from a healed slipped
capital femoral epiphysis (SCFE). We believe this is only the second
such study in the literature. We studied eight patients (eight hips) with symptomatic FAI after
a moderate to severe healed SCFE. There were six male and two female
patients, with a mean age of 17.8 years (13 to 29). All patients underwent a subcapital intracapsular osteotomy of
the femoral neck after surgical hip dislocation and creation of
an extended retinacular soft-tissue flap. The mean follow-up was
41 months (20 to 84). Clinical assessment included measurement of
range of movement, Harris Hip Score (HHS) and Western Ontario and McMaster
Universities Osteoarthritis score (WOMAC). Radiological assessment
included pre- and post-operative calculation of the anterior slip
angle (ASA) and lateral slip angle (LSA), the anterior offset angle
(AOA) and centre head–trochanteric distance (CTD). The mean HHS
at final follow-up was 92.5 (85 to 100), and the mean WOMAC scores
for pain, stiffness and function were 1.3 (0 to 4), 1.4 (0 to 6)
and 3.6 (0 to 19) respectively. There was a statistically significant
improvement in all the radiological measurements post-operatively.
The mean ASA improved from 36.6° (29° to 44°) to 10.3° (5° to 17°)
(p <
0.01). The mean LSA improved from 36.6° (31° to 43°) to 15.4°
(8° to 21°) (p <
0.01). The mean AOA decreased from 64.4° (50°
to 78°) 32.0° (25° to 39°) post-operatively (p <
0.01). The mean
CTD improved from -8.2 mm (-13.8 to +3.1) to +2.8 mm (-7.6 to +11.0)
(p <
0.01). Two patients underwent further surgery for nonunion.
No patient suffered avascular necrosis of the femoral head. Subcapital osteotomy for patients with a healed SCFE is more
challenging than subcapital re-orientation in those with an acute
or sub-acute SCFE and an open physis. An effective correction of
the deformity, however, can be achieved with relief of symptoms
related to impingement. Cite this article:
The most common reasons for revision of unicompartmental
knee arthroplasty (UKA) are loosening and pain. Cementless components
may reduce the revision rate. The aim of this study was to compare
the fixation and clinical outcome of cementless and cemented Oxford
UKAs. A total of 43 patients were randomised to receive either a cemented
or a cementless Oxford UKA and were followed for two years with
radiostereometric analysis (RSA), radiographs aligned with the bone–implant
interfaces and clinical scores. The femoral components migrated significantly during the first
year (mean 0.2 mm) but not during the second. There was no significant
difference in the extent of migration between cemented and cementless
femoral components in either the first or the second year. In the
first year the cementless tibial components subsided significantly
more than the cemented components (mean 0.28 mm ( As second-year migration is predictive of subsequent loosening,
and as radiolucency is suggestive of reduced implant–bone contact,
these data suggest that fixation of the cementless components is
at least as good as, if not better than, that of cemented devices. Cite this article:
The effects of disease progression and common tendinopathy treatments
on the tissue characteristics of human rotator cuff tendons have
not previously been evaluated in detail owing to a lack of suitable
sampling techniques. This study evaluated the structural characteristics
of torn human supraspinatus tendons across the full disease spectrum,
and the short-term effects of subacromial corticosteroid injections
(SCIs) and subacromial decompression (SAD) surgery on these structural
characteristics. Samples were collected inter-operatively from supraspinatus tendons
containing small, medium, large and massive full thickness tears
(n = 33). Using a novel minimally invasive biopsy technique, paired
samples were also collected from supraspinatus tendons containing
partial thickness tears either before and seven weeks after subacromial
SCI (n = 11), or before and seven weeks after SAD surgery (n = 14).
Macroscopically normal subscapularis tendons of older patients (n
= 5, mean age = 74.6 years) and supraspinatus tendons of younger
patients (n = 16, mean age = 23.3) served as controls. Ultra- and
micro-structural characteristics were assessed using atomic force
microscopy and polarised light microscopy respectively. Objectives
Methods
We have evaluated the clinical effectiveness
of a metal resurfacing inlay implant for osteochondral defects of
the medial talar dome after failed previous surgical treatment.
We prospectively studied 20 consecutive patients with a mean age
of 38 years (20 to 60), for a mean of three years (2 to 5) post-surgery.
There was statistically significant reduction of pain in each of
four situations (i.e., rest, walking, stair climbing and running;
p ≤ 0.01). The median American Orthopaedic Foot and Ankle Society
ankle-hindfoot score improved from 62 (interquartile range (IQR)
46 to 72) pre-operatively to 87 (IQR 75 to 95) at final follow-up
(p <
0.001). The Foot and Ankle Outcome Score improved on all
subscales (p ≤ 0.03). The mean Short-Form 36 physical component
scale improved from 36 (23 to 50) pre-operatively to 45 (29 to 55)
at final follow-up (p = 0.001); the mental component scale did not
change significantly. On radiographs, progressive degenerative changes
of the opposing tibial plafond were observed in two patients. One
patient required additional surgery for the osteochondral defect.
This study shows that a metal implant is a promising treatment for
osteochondral defects of the medial talar dome after failed previous
surgery. Cite this article:
The radiological evaluation of the anterolateral femoral head is an essential tool for the assessment of the cam type of femoroacetabular impingement. CT, MRI and frog lateral plain radiographs have all been suggested as imaging options for this type of lesion. The alpha angle is accepted as a reliable indicator of the cam type of impingement and may also be used as an assessment for the successful operative correction of the cam lesion. We studied the alpha angles of 32 consecutive patients with femoroacetabular impingement. The angle measured on frog lateral radiographs using templating tools was compared with that measured on CT scans in order to assess the reliability of the frog lateral view in analysing the alpha angle in cam impingement. A high interobserver reliability was noted for the assessment of the alpha angle on the frog lateral view with an intraclass correlation coefficient of 0.83. The mean alpha angle measured on the frog lateral view was 58.71° (32° to 83.3°) and that by CT was 65.11° (30° to 102°). A poor intraclass correlation coefficient (0.08) was noted between the measurements using the two systems. The frog lateral plain radiograph is not reliable for measuring the alpha angle. Various factors may be responsible for this such as the projection of the radiograph, the positioning of the patient and the quality of the image. CT may be necessary for accurate measurement of the alpha angle.
We report the long-term clinical and radiological outcomes of the Aequalis total shoulder replacement with a cemented all-polyethylene flat-back keeled glenoid component implanted for primary osteoarthritis between 1991 and 2003 in nine European centres. A total of 226 shoulders in 210 patients were retrospectively reviewed at a mean of 122.7 months (61 to 219) or at revision. Clinical outcome was assessed using the Constant score, patient satisfaction score and range of movement. Kaplan-Meier survivorship analysis was performed with glenoid revision for loosening and radiological glenoid loosening ( Younger patient age and the curettage technique for glenoid preparation correlated with loosening. The rate of glenoid revision and radiological loosening increased with duration of follow-up, but not until a follow-up of five years. Therefore, we recommend that future studies reporting radiological outcomes of new glenoid designs should report follow-up of at least five to ten years.
This paper describes the presence of tenodesis effects in normal physiology and explores the uses of operative tenodesis in surgery of the upper limb.
Varus malalignment after total knee replacement is associated with a poor outcome. Our aim was to determine whether the same was true for medial unicompartmental knee replacement (UKR). The anatomical leg alignment was measured prospectively using a long-arm goniometer in 160 knees with an Oxford UKR. Patients were then grouped according to their mechanical leg alignment as neutral (5° to 10° of valgus), mild varus (0° to 4° of valgus) and marked varus (>
0° of varus). The groups were compared at five years in terms of absolute and change in the Oxford Knee score, American Knee Society score and the incidence of radiolucent lines. Post-operatively, 29 (18%) patients had mild varus and 13 (8%) had marked varus. The mean American Knee Society score worsened significantly (p <
0.001) with increasing varus. This difference disappeared if a three-point deduction for each degree of malalignment was removed. No other score deteriorated with increasing varus, and the frequency of occurrence of radiolucent lines was the same in each group. We therefore conclude that after Oxford UKR, about 25% of patients have varus alignment, but that this does not compromise their clinical or radiological outcome. Following UKR the deductions for malalignment in the American Knee Society score are not justified.
Narrow, well-defined radiolucent lines commonly observed at the bone-implant interface of unicompartmental knee replacement tibial components have been referred to as physiological radiolucencies. These should be distinguished from pathological radiolucencies, which are poorly defined, wide and progressive, and associated with loosening and infection. We studied the incidence and clinical significance of tibial radiolucent lines in 161 Oxford unicondylar knee replacements five years after surgery. All the radiographs were aligned with fluoroscopic control to obtain views parallel to the tibial tray to reveal the tibial bone-implant interface. We found that 49 knees (30%) had complete, 52 (32%) had partial and 60 (37%) had no radiolucent lines. There was no relationship between the incidence of radiolucent lines and patient factors such as gender, body mass index and activity, or operative factors including the status of the anterior cruciate ligament and residual varus deformity. Nor was any statistical relationship established between the presence of radiolucent lines and clinical outcome, particularly pain, assessed by the Oxford Knee score and the American Knee Society score. We conclude that radiolucent lines are common after Oxford unicompartmental knee replacement but that their aetiology remains unclear. Radiolucent lines were not a source of adverse symptoms or pain. Therefore, when attempting to identify a source of postoperative pain after Oxford unicompartmental knee replacement the presence of a physiological radiolucency should be ignored.
Wear of polyethylene is associated with aseptic loosening of orthopaedic implants and has been observed in hip and knee prostheses and anatomical implants for the shoulder. The reversed shoulder prostheses have not been assessed as yet. We investigated the volumetric polyethylene wear of the reversed and anatomical Aequalis shoulder prostheses using a mathematical musculoskeletal model. Movement and joint stability were achieved by EMG-controlled activation of the muscles. A non-constant wear factor was considered. Simulated activities of daily living were estimated from After one year of use, the volumetric wear was 8.4 mm3 for the anatomical prosthesis, but 44.6 mm3 for the reversed version. For the anatomical prosthesis the predictions for contact pressure and wear were consistent with biomechanical and clinical data. The abrasive wear of the polyethylene in reversed prostheses should not be underestimated, and further analysis, both experimental and clinical, is required.
We describe the survivorship of the Medial Rotation total knee replacement (TKR) at ten years in 228 cemented primary replacements implanted between October 1994 and October 2006, with their clinical and radiological outcome. This implant has a highly congruent medial compartment, with the femoral component represented by a portion of a sphere which articulates with a matched concave surface on the medial side of the tibial insert. There were 78 men (17 bilateral TKRs) and 111 women (22 bilateral TKRs) with a mean age of 67.9 years (28 to 90). All the patients were assessed clinically and radiologically using the American Knee Society scoring systems. The mean follow-up was for six years (1 to 13) with only two patients lost to follow-up and 34 dying during the period of study, one of whom had required revision for infection. There were 11 revisions performed in total, three for aseptic loosening, six for infection, one for a periprosthetic fracture and one for a painful but well-fixed replacement performed at another centre. With revision for any cause as the endpoint, the survival at ten years was 94.5% (95% CI 85.1 to 100), and with aseptic loosening as the endpoint 98.4% (95% CI 93 to 100). The mean American Knee Society score improved from 47.6 (0 to 88) to 72.2 (26 to 100) and for function from 45.1 (0 to 100) to 93.1 (45 to 100). Radiological review failed to detect migration in any of the surviving knees. The clinical and radiological results of the Medial Rotation TKR are satisfactory at ten years. The increased congruence of the medial compartment has not led to an increased rate of loosening and continued use can be supported.
One of the most controversial issues in total knee replacement is whether or not to resurface the patella. In order to determine the effects of different designs of femoral component on the conformity of the patellofemoral joint, five different knee prostheses were investigated. These were Low Contact Stress, the Miller-Galante II, the NexGen, the Porous-Coated Anatomic, and the Total Condylar prostheses. Three-dimensional models of the prostheses and a native patella were developed and assessed by computer. The conformity of the curvature of the five different prosthetic femoral components to their corresponding patellar implants and to the native patella at different angles of flexion was assessed by measuring the angles of intersection of tangential lines. The Total Condylar prosthesis had the lowest conformity with the native patella (mean 8.58°; 0.14° to 29.9°) and with its own patellar component (mean 11.36°; 0.55° to 39.19°). In the other four prostheses, the conformity was better (mean 2.25°; 0.02° to 10.52°) when articulated with the corresponding patellar component. The Porous-Coated Anatomic femoral component showed better conformity (mean 6.51°; 0.07° to 9.89°) than the Miller-Galante II prosthesis (mean 11.20°; 5.80° to 16.72°) when tested with the native patella. Although the Nexgen prosthesis had less conformity with the native patella at a low angle of flexion, this improved at mid (mean 3.57°; 1.40° to 4.56°) or high angles of flexion (mean 4.54°; 0.91° to 9.39°), respectively. The Low Contact Stress femoral component had the best conformity with the native patella (mean 2.39°; 0.04° to 4.56°). There was no significant difference (p >
0.208) between the conformity when tested with the native patella or its own patellar component at any angle of flexion. The geometry of the anterior flange of a femoral component affects the conformity of the patellofemoral joint when articulating with the native patella. A more anatomical design of femoral component is preferable if the surgeon decides not to resurface the patella at the time of operation.
