The biomechanical function of the anteromedial
(AM) and posterolateral (PL) bundles of the anterior cruciate ligament
(ACL) remains controversial. Some studies report that the AM bundle
stabilises the knee joint in anteroposterior (AP) translation and
rotational movement (both internal and external) to the same extent
as the PL bundle. Others conclude that the PL bundle is more important
than the AM in controlling
Objectives. The objective of this study was to quantify the relative movement between the articular surfaces in the tibiotalar and subtalar joints during normal walking in asymptomatic individuals. Methods. 3D movement data of the ankle joint complex were acquired from 18 subjects using a biplanar fluoroscopic system and 3D-to-2D registration of bone models obtained from CT images. Surface relative velocity vectors (SRVVs) of the articular surfaces of the tibiotalar and subtalar joints were calculated. The relative movement of the articulating surfaces was quantified as the mean relative speed (RS) and synchronization index (SI. ENT. ) of the SRVVs. Results. SI. ENT. and mean RS data showed that the tibiotalar joint exhibited translational movement throughout the stance, with a mean SI. ENT. of 0.54 (. sd. 0.21). The mean RS of the tibiotalar joint during the 0% to 20% post heel-strike phase was 36.0 mm/s (. sd. 14.2), which was higher than for the rest of the stance period. The subtalar joint had a mean SI. ENT. value of 0.43 (. sd. 0.21) during the stance phase and exhibited a greater degree of
The objective of this study was to compare simulated range of motion (ROM) for reverse total shoulder arthroplasty (rTSA) with and without adjustment for scapulothoracic orientation in a global reference system. We hypothesized that values for simulated ROM in preoperative planning software with and without adjustment for scapulothoracic orientation would be significantly different. A statistical shape model of the entire humerus and scapula was fitted into ten shoulder CT scans randomly selected from 162 patients who underwent rTSA. Six shoulder surgeons independently planned a rTSA in each model using prototype development software with the ability to adjust for scapulothoracic orientation, the starting position of the humerus, as well as kinematic planes in a global reference system simulating previously described posture types A, B, and C. ROM with and without posture adjustment was calculated and compared in all movement planes.Aims
Methods
We determined the short-term clinical outcome
and migration within the bone of the humeral cementless component
of the Instrumented Bone Preserving (IBP) total elbow replacement
in a series of 16 patients. There were four men and 12 women with
a mean age at operation of 63 years (40 to 81). Migration was calculated
using radiostereometric analysis. There were no intra-operative
complications and no revisions. At two-year follow-up, all patients
showed a significant reduction in pain and functional improvement
of the elbow (both p <
0.001). Although ten components (63%)
showed movement or micromovement during the first six weeks, 14
(88%) were stable at one year post-operatively. Translation was
primarily found in the proximal direction (median 0.3 mm (interquartile range
(IQR) -0.09 to 0.8); the major
Manual impaction, with a mallet and introducer, remains the standard method of installing cementless acetabular cups during total hip arthroplasty (THA). This study aims to quantify the accuracy and precision of manual impaction strikes during the seating of an acetabular component. This understanding aims to help improve impaction surgical techniques and inform the development of future technologies. Posterior approach THAs were carried out on three cadavers by an expert orthopaedic surgeon. An instrumented mallet and introducer were used to insert cementless acetabular cups. The motion of the mallet, relative to the introducer, was analyzed for a total of 110 strikes split into low-, medium-, and high-effort strikes. Three parameters were extracted from these data: strike vector, strike offset, and mallet face alignment.Aims
Methods
Despite limited clinical scientific backing, an additional trochanteric stabilizing plate (TSP) has been advocated when treating unstable trochanteric fractures with a sliding hip screw (SHS). We aimed to explore whether the TSP would result in less post operative fracture motion, compared to SHS alone. Overall, 31 patients with AO/OTA 31-A2 trochanteric fractures were randomized to either a SHS alone or a SHS with an additional TSP. To compare postoperative fracture motion, radiostereometric analysis (RSA) was performed before and after weightbearing, and then at four, eight, 12, 26, and 52 weeks. With the “after weightbearing” images as baseline, we calculated translations and rotations, including shortening and medialization of the femoral shaft.Aims
Methods
The aim of this study was to assess and compare active rotation of the forearm in normal subjects after the application of a short-arm cast (SAC) in the semisupination position and a long-arm cast (LAC) in the neutral position. A clinical study was also conducted to compare the functional outcomes of using a SAC in the semisupination position with those of using a LAC in the neutral position in patients who underwent arthroscopic triangular fibrocartilage complex (TFCC) foveal repair. A total of 40 healthy right-handed volunteers were recruited. Active pronation and supination of the forearm were measured in each subject using a goniometer. In the retrospective clinical study, 40 patients who underwent arthroscopic foveal repair were included. The wrist was immobilized postoperatively using a SAC in the semisupination position (approximately 45°) in 16 patients and a LAC in 24. Clinical outcomes were assessed using grip strength and patient-reported outcomes. The degree of disability caused by cast immobilization was also evaluated when the cast was removed.Aims
Methods
1. The history of the genesis of the Putti-Platt operation for habitual dislocation of the shoulder is outlined so far as it is known. 2. The operation is described and briefly commented upon. 3. Since there is both gleno-labrial detachment and defect in the humeral head successful treatment depends upon: i) a block to the exit of the humeral head in front and ii) limitation of external
We examined 50 patients with diastrophic dysplasia both clinically and radiologically. Two legally aborted fetuses were dissected. The mean age of the patients was 16.2 years (newborn to 38) and the mean follow-up was 11.4 years (3 months to 34 years). The fetal hips and MRI of newborn infants showed congruity and no significant joint deformity. Flexion contracture of the hip became evident later in 93% and was progressive. The radiological appearance of the proximal femoral ossific nuclei was delayed and in 17% of males and 28% of females the ossific nuclei had not appeared by the age of 12 years. Radiological measurements differed considerably from reference values and were related to the rapid and progressive restriction of
An attempt has been made to describe some of the ways in which the element of rotation, which is so important a part of the function of the normal forearm, has a bearing upon the mechanism and treatment of forearm injuries. In particular, distinction is drawn between those injuries in which the shaft of the radius remains in continuity, and those in which there is a complete fracture of the bone. In the former, rotation of the hand in the reduction will be transmitted to the upper end of the radius, and extremes of
The aim of this study was to conduct the largest low contact stress (LCS) retrieval study to elucidate the failure mechanisms of the Porocoat and Duofix femoral component. The latter design was voluntarily recalled by the manufacturer. Uncemented LCS explants were divided into three groups: Duofix, Porocoat, and mixed. Demographics, polyethylene wear, tissue ingrowth, and metallurgical analyses were performed.Aims
Materials and Methods
Scapular notching is a frequently observed radiographic phenomenon
in reverse shoulder arthroplasty (RSA), signifying impingement of
components. The purposes of this study were to evaluate the effect
of glenoid component size and glenosphere type on impingement-free
range of movement (ROM) for extension and internal and external
rotation in a virtual RSA model, and to determine the optimal configuration
to reduce the incidence of friction-type scapular notching. Preoperative CT scans obtained in 21 patients (three male, 18
female) with primary osteoarthritis were analyzed using modelling
software. Two concurrent factors were tested for impingement-free
ROM and translation of the centre of rotation: glenosphere diameter
(36 mm Aims
Materials and Methods
Aims
Patients and Methods
To validate the precision of digitally reconstructed radiograph (DRR) radiostereometric analysis (RSA) and the model-based method (MBM) RSA with respect to benchmark marker-based (MM) RSA for evaluation of kinematics in the native hip joint. Seven human cadaveric hemipelves were CT scanned and bone models were segmented. Tantalum beads were placed in the pelvis and proximal femoral bone. RSA recordings of the hips were performed during flexion, adduction and internal rotation. Stereoradiographic recordings were all analyzed with DRR, MBM and MM. Migration results for the MBM and DRR with respect to MM were compared. Precision was assessed as systematic bias (mean difference) and random variation (Pitman’s test for equal variance).Objectives
Methods
The objective of this study was to investigate bone healing after
internal fixation of displaced femoral neck fractures (FNFs) with
the Dynamic Locking Blade Plate (DLBP) in a young patient population
treated by various orthopaedic (trauma) surgeons. We present a multicentre prospective case series with a follow-up
of one year. All patients aged ≤ 60 years with a displaced FNF treated
with the DLBP between 1st August 2010 and December 2014 were included.
Patients with pathological fractures, concomitant fractures of the
lower limb, symptomatic arthritis, local infection or inflammation,
inadequate local tissue coverage, or any mental or neuromuscular
disorder were excluded. Primary outcome measure was failure in fracture
healing due to nonunion, avascular necrosis, or implant failure
requiring revision surgery.Aims
Patients and Methods
Computer hexapod assisted orthopaedic surgery (CHAOS), is a method
to achieve the intra-operative correction of long bone deformities
using a hexapod external fixator before definitive internal fixation
with minimally invasive stabilisation techniques. The aims of this study were to determine the reliability of this
method in a consecutive case series of patients undergoing femoral
deformity correction, with a minimum six-month follow-up, to assess
the complications and to define the ideal group of patients for
whom this treatment is appropriate. The medical records and radiographs of all patients who underwent
CHAOS for femoral deformity at our institution between 2005 and
2011 were retrospectively reviewed. Records were available for all
55 consecutive procedures undertaken in 49 patients with a mean
age of 35.6 years (10.9 to 75.3) at the time of surgery.Aims
Patients and Methods
This prospective multicentre study was undertaken
to determine segmental movement, disc height and sagittal alignment
after total disc replacement (TDR) in the lumbosacral spine and
to assess the correlation of biomechanical properties to clinical
outcomes. A total of 173 patients with degenerative disc disease and low
back pain for more than one year were randomised to receive either
TDR or multidisciplinary rehabilitation (MDR). Segmental movement
in the sagittal plane and disc height were measured using distortion
compensated roentgen analysis (DCRA) comparing radiographs in active flexion
and extension. Correlation analysis between the range of movement
or disc height and patient-reported outcomes was performed in both
groups. After two years, no significant change in movement in the
sagittal plane was found in segments with TDR or between the two
treatment groups. It remained the same or increased slightly in
untreated segments in the TDR group and in this group there was
a significant increase in disc height in the operated segments.
There was no correlation between segmental movement or disc height
and patient-reported outcomes in either group. In this study, insertion of an intervertebral disc prosthesis
TDR did not increase movement in the sagittal plane and segmental
movement did not correlate with patient-reported outcomes. This
suggests that in the lumbar spine the movement preserving properties
of TDR are not major determinants of clinical outcomes. Cite this article:
The interaction between the lumbosacral spine
and the pelvis is dynamically related to positional change, and
may be complicated by co-existing pathology. This review summarises
the current literature examining the effect of sagittal spinal deformity
on pelvic and acetabular orientation during total hip arthroplasty
(THA) and provides recommendations to aid in placement of the acetabular
component for patients with co-existing spinal pathology or long
spinal fusions. Pre-operatively, patients can be divided into four
categories based on the flexibility and sagittal balance of the
spine. Using this information as a guide, placement of the acetabular
component can be optimal based on the type and significance of co-existing
spinal deformity. Cite this article:
The use of hinged implants in primary total knee
replacement (TKR) should be restricted to selected indications and mainly
for elderly patients. Potential indications for a rotating hinge
or pure hinge implant in primary TKR include: collateral ligament
insufficiency, severe varus or valgus deformity (>
20°) with necessary
relevant soft-tissue release, relevant bone loss including insertions
of collateral ligaments, gross flexion-extension gap imbalance,
ankylosis, or hyperlaxity. Although data reported in the literature
are inconsistent, clinical results depend on implant design, proper
technical use, and adequate indications. We present our experience
with a specific implant type that we have used for over 30 years
and which has given our elderly patients good mid-term results.
Because revision of implants with long cemented stems can be very
challenging, an effort should be made in the future to use shorter stems
in modular versions of hinged implants. Cite this article:
We examined the reliability of radiological findings in predicting segmental instability in 112 patients (56 men, 56 women) with a mean age of 66.5 years (27 to 84) who had degenerative disease of the lumbar spine. They underwent intra-operative biomechanical evaluation using a new measurement system. Biomechanical instability was defined as a segment with a neutral zone >
2 mm/N. Risk factor analysis to predict instability was performed on radiographs (range of segmental movement, disc height), MRI (Thompson grade, Modic type), and on the axial CT appearance of the facet (type, opening, vacuum and the presence of osteophytes, subchondral erosion, cysts and sclerosis) using multivariate logistic regression analysis with a forward stepwise procedure. The facet type was classified as sagittally orientated, coronally orientated, anisotropic or wrapped. Stepwise multivariate regression analysis revealed that facet opening was the strongest predictor for instability (odds ratio 5.022, p = 0.009) followed by spondylolisthesis, MRI grade and subchondral sclerosis. Forward stepwise multivariate logistic regression indicated that spondylolisthesis, MRI grade, facet opening and subchondral sclerosis of the facet were risk factors. Symptoms evaluated by the Short-Form 36 and visual analogue scale showed that patients with an unstable segment were in significantly more pain than those without. Furthermore, the surgical procedures determined using the intra-operative measurement system were effective, suggesting that segmental instability influences the symptoms of lumbar degenerative disease.
There were 47 patients with congenital muscular torticollis who underwent operative release. After a mean follow-up of 74 months (60 to 90), they were divided into two groups, one aged one to four years (group 1) and the other aged five to 16 years (group 2). The outcomes were assessed by evaluating the following parameters: deficits of lateral flexion and rotation, craniofacial asymmetry, surgical scarring, residual contracture, subjective evaluation and degree of head tilt. The craniofacial asymmetry, residual contracture, subjective evaluation and overall scores were similar in both groups. However, group 2 showed superior results to group 1 in terms of the deficits of movement, surgical scarring and degree of head tilt. It is recommended that operative treatment for congenital muscular torticollis is postponed until the patient can comply successfully with post-operative bracing and an exercise programme.
Mobile-bearing (MB) total knee replacement (TKR)
was introduced to reduce the risk of aseptic loosening and wear of
polyethylene inserts. However, no consistent clinical advantages
of mobile- over fixed-bearing (FB) TKR have been found. In this
study we evaluated whether mobile bearings have an advantage over
fixed bearings with regard to revision rates and clinical outcome
scores. Furthermore, we determined which modifying variables affected
the outcome. A systematic search of the literature was conducted to collect
clinical trials comparing MB and FB in primary TKR. The primary
outcomes were revision rates for any reason, aseptic loosening and
wear. Secondary outcomes included range of movement, Knee Society
score (KSS), Oxford knee score (OKS), Short-Form 12 (SF-12) score
and radiological parameters. Meta-regression techniques were used
to explore factors modifying the observed effect. Our search yielded 1827 publications, of which 41 studies met
our inclusion criteria, comprising over 6000 TKRs. Meta-analyses
showed no clinically relevant differences in terms of revision rates,
clinical outcome scores or patient-reported outcome measures between
MB and FB TKRs. It appears that theoretical assumptions of superiority
of MB over FB TKR are not borne out in clinical practice. Cite this article:
Radiostereometric analysis (RSA) can detect early
micromovement in unstable implant designs which are likely subsequently
to have a high failure rate. In 2010, the Articular Surface Replacement
(ASR) was withdrawn because of a high failure rate. In 19 ASR femoral
components, the mean micromovement over the first two years after implantation
was 0.107 mm ( We conclude that the ASR femoral component achieves initial stability
and that early migration is not the mode of failure for this resurfacing
arthroplasty.
Components from 73 failed knee replacements (TKRs) consisting of rotating-platform, mobile-bearing and fixed-bearing implants were examined to assess the patterns of wear. The patterns were divided into low-grade (burnishing, abrasion and cold flow) and high-grade (scratching, pitting/metal embedding and delamination) to assess the severity of the wear of polyethylene. The rotating-platform group had a higher incidence of low-grade wear on the upper surface compared with the fixed-bearing group. By contrast, high-grade wear comprising scratching, pitting and third-body embedding was seen on the lower surface. Linear regression analysis showed a significant correlation of the wear scores between the upper and lower surfaces of the tibial insert (R2 = 0.29, p = 0.04) for the rotating-platform group, but no significant correlation was found for the fixed-bearing counterpart. This suggests that high-grade wear patterns on the upper surface are reduced with the rotating-platform design. However, the incidence of burnishing, pitting/third-body embedding and scratching wear patterns on the lower surface was higher compared with that in the fixed-bearing knee.
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.
Osteoarthritis is extremely common and many different causes for it have been described. One such cause is abnormal morphology of the affected joint, the hip being a good example of this. For those joints with femoroacetabular impingement (FAI) or developmental dysplasia of the hip (DDH), a link with subsequent osteoarthritis seems clear. However, far from being abnormal, these variants may be explained by evolution, certainly so for FAI, and may actually be normal rather than representing deformity or disease. The animal equivalent of FAI is coxa recta, commonly found in species that run and jump. It is rarely found in animals that climb and swim. In contrast are the animals with coxa rotunda, a perfectly spherical femoral head, and more in keeping with the coxa profunda of mankind. This article describes the evolutionary process of the human hip and its link to FAI and DDH. Do we need to worry after all?
This study compared the outcome of total knee
replacement (TKR) in adult patients with fixed- and mobile-bearing prostheses
during the first post-operative year and at five years’ follow-up,
using gait parameters as a new objective measure. This double-blind
randomised controlled clinical trial included 55 patients with mobile-bearing (n
= 26) and fixed-bearing (n = 29) prostheses of the same design,
evaluated pre-operatively and post-operatively at six weeks, three
months, six months, one year and five years. Each participant undertook
two walking trials of 30 m and completed the EuroQol questionnaire,
Western Ontario and McMaster Universities osteoarthritis index,
Knee Society score, and visual analogue scales for pain and stiffness.
Gait analysis was performed using five miniature angular rate sensors
mounted on the trunk (sacrum), each thigh and calf. The study population
was divided into two groups according to age (≤ 70 years Improvements in most gait parameters at five years’ follow-up
were greater for fixed-bearing TKRs in older patients (>
70 years),
and greater for mobile-bearing TKRs in younger patients (≤ 70 years).
These findings should be confirmed by an extended age controlled
study, as the ideal choice of prosthesis might depend on the age
of the patient at the time of surgery.
We describe the long-term results in ten patients with obstetric brachial plexus palsy of anterior shoulder release combined with transfer of teres major and latissimus dorsi posteriorly and laterally to allow them to act as external rotators. Eight patients had a lesion of the superior trunk and two some involvement of the entire brachial plexus. The mean age at operation was six years, and the mean follow-up was 30 years. Before operation, the patients were unable actively to rotate the arm externally beyond neutral, although this movement was passively normal. All showed decreased strength of the external rotator, but had normal strength of the internal rotator muscles. Radiologically, no severe bony changes were seen in the glenohumeral joint. No clinically detectable improvement of active abduction was noted in any patient. The mean active external rotation after operation was 36.5°. This was maintained for a mean of ten years, and then deteriorated in eight patients. At the latest follow-up the mean active external rotation was 10.5°. The early satisfactory results of the procedure were not maintained. In the long term there was loss of active external rotation, possibly because of gradual degeneration of the transferred muscles, contracture of the surrounding soft tissues and degenerative changes in the glenohumeral joint.
Metallosis is a rare cause of failure after total knee replacement and has only previously been reported when there has been abnormal metal-on-metal contact. We describe 14 patients (15 knees) whose total knee replacement required revision for a new type of early failure caused by extensive metallosis. A modification of a cementless rotating platform implant, which had previously had excellent long-term survival, had been used in each case. The change was in the form of a new porous-beaded surface on the femoral component to induce cementless fixation, which had been used successfully in the fixation of acetabular and tibial components. This modification appeared to have resulted in metallosis due to abrasive two-body wear. The component has subsequently been recalled and is no longer in use. The presentation, investigation, and findings at revision are described and a possible aetiology and its implications are discussed.
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.
Valgus high tibial osteotomy for osteoarthritis of the medial compartment of the knee can be performed using medial opening- and lateral closing-wedge techniques. The latter have been thought to offer greater initial stability. We measured and compared the stability of opening- and closing-wedge osteotomies fixed by TomoFix plates using radiostereometry in a series of 42 patients in a prospective, randomised clinical trial. There were no differences between the opening- and closing-wedge groups in the time to regain knee function and full weight-bearing. Pain and knee function were significantly improved in both groups without any differences between them. All the osteotomies united within one year. Radiostereometry showed no clinically relevant movement of bone or differences between either group. Medial opening-wedge high tibial osteotomy secured by a TomoFix plate offers equal stability to a lateral closing-wedge technique. Both give excellent initial stability and provide significantly improved knee function and reduction in pain, although the opening-wedge technique was more likely to produce the intended correction.
We describe 14 patients who underwent transfer of latissimus dorsi using a new technique through a single-incision. Their mean age was 61 years (47 to 76) and the mean follow-up was 32 months (19 to 42). The mean Constant score improved from 46.5 to 74.6 points. The mean active flexion increased from 119° to 170°, mean abduction from 118° to 169° and mean external rotation from 19° to 33°. The Hornblower sign remained positive in three patients (23%) as did the external rotation lag sign also in three patients (23%). No patient had a positive drop-arm sign at follow-up. No significant difference was noted between the mean pre- and postoperative acromiohumeral distance as seen on radiographs. An increased grade of osteoarthritis was found in three patients (23%). Electromyographic analysis showed activity of the transferred muscle in all patients.
Between January 1984 and January 1986, 131 porous-coated anatomic total hip replacements were performed in 119 consecutive patients. Of these, 100 patients (110 hips) who were alive at a minimum of 18 years after replacement were included in the study. The mean age of the patients at surgery was 48.4 years and that of surviving patients at the latest follow-up was 67.8 years. The mean duration of the clinical and radiological follow-up was 19.4 years (18 to 20). The mean Harris hip score initially improved from 55 points before to 95 points at two years after operation, but subsequently decreased to 91 points after six years, 87 points after 11.2 years, and 85 points after 19.4 years. At the final follow-up, 23 hips (18%) of the entire cohort and 21% of survivors had undergone revision because of loosening or osteolysis of the acetabular component and eight hips (6%) of the entire cohort and 7% of survivors for loosening or osteolysis of the femoral component. Only four femoral components (4%) were revised for isolated aseptic loosening without osteolysis and two (2%) for recurrent dislocation. On the basis of these long-term results, the porous-coated anatomic femoral component survived for a minimum of 18 years after operation while the acetabular component was less durable. The findings identify the principles of uncemented joint replacement which can be applied to current practice.
We studied retrospectively the results of revision arthroplasty of the elbow using a linked Coonrad-Morrey implant in 23 patients (24 elbows) after a mean follow-up period of 55 months. According to the Mayo Elbow Performance Score, 19 elbows were satisfactory, nine were excellent and ten good. The median total score had improved from 35 points (20 to 75) before the primary arthroplasty to 85 points (40 to 100) at the latest follow-up. There was a marked relief of pain, but the range of movement showed no overall improvement. Two patients had a second revision because of infection and two for aseptic loosening. The estimated five-year survival rate of the prosthesis was 83.1% (95% confidence interval 61.1 to 93.3). Revision elbow arthroplasty using the Coonrad-Morrey implant provided satisfactory results but with complications occurring in 13 cases.
The treatment of fractures of the proximal tibia is complex and makes great demands on the implants used. Our study aimed to identify what levels of primary stability could be achieved with various forms of osteosynthesis in the treatment of diaphyseal fractures of the proximal tibia. Pairs of human tibiae were investigated. An unstable fracture was simulated by creating a defect at the metaphyseal-diaphyseal junction. Six implants were tested in a uniaxial testing device (Instron) using the quasi-static and displacement-controlled modes and the force-displacement curve was recorded. The movements of each fragment and of the implant were recorded video-optically (MacReflex, Qualysis). Axial deviations were evaluated at 300 N. The results show that the nailing systems tolerated the highest forces. The lowest axial deviations in varus and valgus were also found for the nailing systems; the highest axial deviations were recorded for the buttress plate and the less invasive stabilising system (LISS). In terms of rotational displacement the LISS was better than the buttress plate. In summary, it was found that higher loads were better tolerated by centrally placed load carriers than by eccentrically placed ones. In the case of the latter, it appears advantageous to use additive procedures for medial buttressing in the early phase.
Over an eight-month period we prospectively enrolled 122 patients who underwent arthroscopic surgery of the hip for femoroacetabular impingement and met the inclusion criteria for this study. Patients with bilateral hip arthroscopy, avascular necrosis and previous hip surgery were excluded. Ten patients refused to participate leaving 112 in the study. There were 62 women and 50 men. The mean age of the patients was 40.6 yrs (95% confidence interval (CI) 37.7 to 43.5). At arthroscopy, 23 patients underwent osteoplasty only for cam impingement, three underwent rim trimming only for pincer impingement, and 86 underwent both procedures for mixed-type impingement. The mean follow-up was 2.3 years (2.0 to 2.9). The mean modified Harris hip score (HHS) improved from 58 to 84 (mean difference = 24 (95% CI 19 to 28)) and the median patient satisfaction was 9 (1 to 10). Ten patients underwent total hip replacement at a mean of 16 months (8 to 26) after arthroscopy. The predictors of a better outcome were the pre-operative modified HHS (p = 0.018), joint space narrowing ≥ 2 mm (p = 0.005), and repair of labral pathology instead of debridement (p = 0.032). Hip arthroscopy for femoroacetabular impingement, accompanied by suitable rehabilitation, gives a good short-term outcome and high patient satisfaction.