The aim of this study was to evaluate the prosthesis characteristics and associated conditions that may modify the survival of total femoral endoprosthetic replacements (TFEPR). In all, 81 patients treated with TFEPR from 1976 to 2017 were retrospectively evaluated and failures were categorized according to the Henderson classification. There were 38 female patients (47%) and 43 male patients (53%) with a mean age at diagnosis of 43 years (12 to 86). The mean follow-up time was 10.3 years (0 to 31.7). A survival analysis was performed followed by univariate and multivariate Cox regression to identify independent implant survival factors.Aims
Patients and Methods
The aim of this study was to analyze the true costs associated with preoperative CT scans performed for robotic-assisted total knee arthroplasty (RATKA) planning and to determine the value of a formal radiologist’s report of these studies. We reviewed 194 CT reports of 176 sequential patients who underwent primary RATKA by a single surgeon at a suburban teaching hospital. CT radiology reports were reviewed for the presence of incidental findings that might change the management of the patient. Payments for the scans, including the technical and professional components, for 330 patients at two hospitals were also recorded and compared.Aims
Methods
The aim of this study was to analyse the gait
pattern, muscle force and functional outcome of patients who had undergone
replacement of the proximal tibia for tumour and alloplastic reconstruction
of the extensor mechanism using the patellar-loop technique. Between February 1998 and December 2009, we carried out wide
local excision of a primary sarcoma of the proximal tibia, proximal
tibial replacement and reconstruction of the extensor mechanism
using the patellar-loop technique in 18 patients. Of these, nine
were available for evaluation after a mean of 11.6 years (0.5 to
21.6). The strength of the knee extensors was measured using an
Isobex machine and gait analysis was undertaken in our gait assessment
laboratory. Functional outcome was assessed using the American Knee
Society (AKS) and Musculoskeletal Tumor Society (MSTS) scores. The gait pattern of the patients differed in ground contact time,
flexion heel strike, maximal flexion loading response and total
sagittal plane excursion. The mean maximum active flexion was 91°
(30° to 110°). The overall mean extensor lag was 1° (0° to 5°).
The mean extensor muscle strength was 25.8% (8.3% to 90.3%) of that
in the non-operated leg (p <
0.001). The mean functional scores
were 68.7% (43.4% to 83.3%) (MSTS) and 71.1 (30 to 90) (AKS functional
score). In summary, the results show that reconstruction of the extensor
mechanism using this technique gives good biomechanical and functional
results. The patients’ gait pattern is close to normal, except for
a somewhat stiff knee gait pattern. The strength of the extensor
mechanism is reduced, but sufficient for walking. Cite this article:
Many radiographic techniques have been described for measuring patellar height. They can be divided into two groups: those that relate the position of the patella to the femur (direct) and those that relate it to the tibia (indirect). This article looks at the methods that have been described, the logic behind their conception and the critical analyses that have been performed to test them.
Chronic patellofemoral instability can be a disabling condition. Management of patients with this condition has improved owing to our increased knowledge of the functional anatomy of the patellofemoral joint. Accurate assessment of the underlying pathology in the unstable joint enables the formulation of appropriate treatment. The surgical technique employed in patients for whom non-operative management has failed should address the diagnosed abnormality. We have reviewed the literature on the stabilising features of the patellofemoral joint, the recommended investigations and the appropriate forms of treatment.
An abnormal lateral position of the tibial tuberosity causes distal malalignment of the extensor mechanism of the knee and can lead to lateral tracking of the patella causing anterior knee pain or objective patellar instability, characterised by recurrent dislocation. Computer tomography is used for a precise pre-operative assessment of the tibial tubercle-trochlear groove distance. A distance of more than 15 mm is considered to be pathological and an indication for surgery in symptomatic patients. In a prospective study we performed a subtle transfer of the tibial tuberosity according to the information gained from the pre-operative CT scan. This method was applied to two groups of patients, those with painful lateral tracking of the patella, and those with objective patellar instability. We evaluated the clinical results in 30 patients in each group. The outcome was documented at 3, 12 and 24 months using the Lysholm scale, the Kujala score, and a visual analogue pain score. Post-operatively, all but one patient in the instability group who had a patellar dislocation requiring further surgery reported good improvement with no further subluxation or dislocation. All patients in both groups had a marked improvement in pain and functional score. Two patients sustained a tibial fracture six and seven weeks after surgery. One patient suffered a per-operative fracture of the tibial tubercle which later required further fixation. If carefully performed, this type of transfer of the tibial tubercle appears to be a satisfactory technique for the treatment of patients with an increased tibial tubercle-trochlear groove distance and who present with symptoms related to lateral maltracking of the patella.
We evaluated the outcome in a series of patients with recurrent patellar dislocation who had either medial transfer of the tibial tuberosity and lateral release or an isolated lateral release as the primary treatment. The decision to use one or other procedure was based on a pre-operative distance between the tibial tuberosity to the trochlear groove (TTTG) of less than 10 mm to include the tibial tuberosity transfer in addition to the lateral release. Between April 2002 and December 2006, 49 patients (63 knees) underwent one of these procedures. A total of 35 patients (46 knees) was evaluated at a mean of 38 months (13 to 71) post-operatively. Medial transfer of the tibial tuberosity was performed in 33 knees and isolated lateral release in the remaining 13. Evaluation included the International Knee Documentation Committee (IKDC), the Kujala and the Short-form 36 scores. From the tibial tuberosity group 23 knees also underwent radiological examination at follow-up. There were further episodes of patellar dislocation in six of the 46 knees available for review. Further dislocation was noted in five of 33 knees (15.2%) in the tibial tuberosity transfer group and in one of 13 knees (7.7%) in the lateral release group. The mean subjective IKDC score was 80.4 (
We describe our experience with the ‘four-in-one’ procedure for habitual dislocation of the patella in five children (six knees). All the patients presented with severe generalised ligamentous laxity and aplasia of the trochlear groove. All had a lateral release, proximal ‘tube’ realignment of the patella, semitendinosus tenodesis and transfer of the patellar tendon. The mean age at the time of the operation was 6.1 years (4.9 to 6.9), and the patients were followed up for a mean of 54.5 months (31 to 66). The clinical results were evaluated using the Kujala score. There has been no recurrence of dislocation. All the patients have returned to full activities and the parents and children were satisfied with the clinical results. The mean Kujala score was 95.3 (88 to 98). Two patients had marginal skin necrosis which healed after debridement and secondary closure. These early results in this small group have shown that the ‘four-in-one’ procedure is effective in the treatment of obligatory dislocation of the patella in children with severe ligamentous laxity and trochlear aplasia.
The outcome of high tibial osteotomy (HTO) deteriorates
with time, and additional procedures may be required. The aim of
this study was to compare the clinical and radiological outcomes
between unicompartmental knee replacement (UKR) and total knee replacement
(TKR) after HTO as well as after primary UKR. A total of 63 patients (63
knees) were studied retrospectively and divided into three groups:
UKR after HTO (group A; n = 22), TKR after HTO (group B; n = 18)
and primary UKR (group C; n = 22). The Oxford knee score (OKS),
Knee Society score (KSS), hip–knee–ankle angles, mechanical axis
and patellar height were evaluated pre- and post-operatively. At
a mean of 64 months (19 to 180) post-operatively the mean OKS was
43.8 (33 to 49), 43.3 (30 to 48) and 42.5 (29 to 48) for groups
A, B and C, respectively (p = 0.73). The mean KSS knee score was
88.8 (54 to 100), 88.11 (51 to 100) and 85.3 (45 to 100) for groups
A, B and C, respectively (p = 0.65), and the mean KSS function score
was 85.0 (50 to 100) in group A, 85.8 (20 to 100) in group B and
79.3 (50 to 100) in group C (p = 0.48). Radiologically the results
were comparable for all groups except for patellar height, with
a higher incidence of patella infra following a previous HTO (p
= 0.02). Cite this article:
The Bereiter trochleoplasty has been used in our unit for 12
years to manage recurrent patellar instability in patients with
severe trochlea dysplasia. The aim of this study was to document
the outcome of a large consecutive cohort of patients who have undergone
this operation. Between June 2002 and August 2013, 214 consecutive trochleoplasties
were carried out in 185 patients. There were 133 women and 52 men
with a mean age of 21.3 years (14 to 38). All patients were offered
yearly clinical and radiological follow-up. They completed the following
patient reported outcome scores (PROMs): International Knee Documentation
Committee subjective scale, the Kujala score, the Western Ontario
and McMaster Universities Arthritis Index score and the short-form
(SF)-12. Aims
Patients and Methods
The effect of weight-bearing on the height of the patellar using four radiological indices was studied in 25 healthy men using lateral radiographs of the knee in 30° of flexion non-weight-bearing and weight-bearing. The position of the patella was quantified using the Insall-Salvati, the modified Insall-Salvati, the Blackburne-Peel and the Caton indices. The contraction of the quadriceps on weight-bearing resulted in statistically significant proximal displacement of the patella with all four indices studied. The mean Insall-Salvati index was 0.919 ( The effect of quadriceps contraction should be considered in clinical studies where the patellar position indices are reported.
We present the ten- to 15-year follow-up of 31
patients (34 knees), who underwent an Elmslie-Trillat tibial tubercle osteotomy
for chronic, severe patellar instability, unresponsive to non-operative
treatment. The mean age of the patients at the time of surgery was
31 years (18 to 46) and they were reviewed post-operatively, at
four years (2 to 8) and then at 12 years (10 to 15). All patients
had pre-operative knee radiographs and Cox and Insall knee scores. Superolateral
portal arthroscopy was performed per-operatively to document chondral
damage and after the osteotomy to assess the stability of the patellofemoral
joint. A total of 28 knees (82%) had a varying degree of damage
to the articular surface. At final follow-up 25 patients (28 knees)
were available for review and underwent clinical examination, radiographs
of the knee, and Cox and Insall scoring. Six patients who had no
arthroscopic chondral abnormality showed no or only early signs
of osteoarthritis on final radiographs; while 12 patients with lower
grade chondral damage (grade 1 to 2) showed early to moderate signs
of osteoarthritis and six out of ten knees with higher grade chondral
damage (grade 3 to 4) showed marked evidence of osteoarthritis;
four of these had undergone a knee replacement. In the 22 patients
(24 knees) with complete follow-up, 19 knees (79.2%) were reported
to have a good or excellent outcome at four years, while 15 knees
(62.5%) were reported to have the same at long-term follow-up. The
functional and radiological results show that the extent of pre-operatively
sustained chondral damage is directly related to the subsequent
development of patellofemoral osteoarthritis. Cite this article:
Seven stiff total knee arthroplasties are presented
to illustrate the roles of: 1) manipulation under general anesthesia;
2) multiple concurrent diagnoses in addition to stiffness; 3) extra-articular
pathology; 4) pain as part of the stiffness triad (pain and limits
to flexion or extension); 5) component internal rotation; 6) multifactorial
etiology; and 7) surgical exposure in this challenging clinical
problem.
The management of osteoarthritis of the knee associated with patellar instability secondary to external tibial torsion >
45° is challenging. Patellofemoral biomechanics in these patients cannot be achieved by intra-articular correction using standard techniques of total knee replacement. We reviewed seven patients (eight knees) with recurrent patellar dislocation and one with bilateral irreducible lateral dislocation who had undergone simultaneous total knee replacement and internal tibial derotational osteotomy. All had osteoarthritis and severe external tibial torsion. The mean follow-up was for 47.2 months (24 to 120). The mean objective and functional Knee Society scores improved significantly (p = 0.0001) from 29.7 and 41.5 pre-operatively to 71.4 and 73.5 post-operatively, respectively. In all patients the osteotomies healed and patellar stability was restored. Excessive external tibial torsion should be identified and corrected in patients with osteoarthritis and patellar instability. Simultaneous internal rotation osteotomy of the tibia and total knee replacement is a technically demanding but effective treatment for such patients.
Single-event multilevel surgery (SEMLS) has been used as an effective
intervention in children with bilateral spastic cerebral palsy (BSCP)
for 30 years. To date there is no evidence for SEMLS in adults with
BSCP and the intervention remains focus of debate. This study analysed the short-term outcome (mean 1.7 years, standard
deviation 0.9) of 97 ambulatory adults with BSCP who performed three-dimensional
gait analysis before and after SEMLS at one institution. Aims
Methods
Trochlear dysplasia is a developmental condition characterised by an abnormally flat or dome-shaped trochlea and is an important contributory factor to patellofemoral instability and recurrent dislocation. We studied prospectively a series of 54 consecutive patients (59 knees) with patellofemoral instability secondary to trochlear dysplasia, who were treated by a trochleoplasty by a single surgeon between June 2002 and June 2007. Pre- and post-operative scores were assessed by the patients and a satisfaction questionnaire was completed. Of the 54 patients (59 knees) in the series, 39 (44 knees) were female and 15 (15 knees) were male. Their mean age at surgery was 21 years and 6 months (14 years 4 months to 33 years 11 months). In 40 patients (42 knees) the mean follow-up was for 24 months (12 to 58). One patient was unable to attend for follow-up. An analysis of the results of those patients followed up for at least 12 months showed a statistically significant improvement in outcome (p <
0.001 for all scores). Overall, 50 patients (92.6%) were satisfied with the outcome of their procedure. The early results of trochleoplasty are encouraging in this challenging group of patients.
Trochlear dysplasia is an important anatomical abnormality in symptomatic patellar instability. Our study assessed the mismatch between the bony and cartilaginous morphology in patients with a dysplastic trochlea compared with a control group. MRI scans of 25 knees in 23 patients with trochlear dysplasia and in 11 patients in a randomly selected control group were reviewed retrospectively in order to assess the morphology of the cartilaginous and bony trochlea. Inter- and intra-observer error was assessed. In the dysplastic group there were 15 women and eight men with a mean age of 20.4 years (14 to 30). The mean bony sulcus angle was 167.9° (141° to 203°), whereas the mean cartilaginous sulcus angle was 186.5° (152° to 214°; p <
0.001). In 74 of 75 axial images (98.7%) the cartilaginous contour was different from the osseous contour on subjective assessment, the cartilage exacerbated the abnormality. Our study shows that the morphology of the cartilaginous trochlea differs markedly from that of the underlying bony trochlea in patients with trochlear dysplasia. MRI is necessary in order to demonstrate the pathology and to facilitate surgical planning.
An increased tibial tubercle–trochlear groove
(TT-TG) distance is related to patellar maltracking and instability.
Tibial tubercle transfer is a common treatment option for these
patients with good short-term results, although the results can
deteriorate over time owing to the progression of osteoarthritis.
We present a ten-year follow-up study of a self-centring tibial
tubercle osteotomy in 60 knees, 30 with maltracking and 30 with
patellar instability. Inclusion criteria were a TT-TG ≥ 15 mm and
symptoms for >
one year. One patient (one knee) was lost to follow-up
and one required total knee arthroplasty because of progressive
osteoarthritis. Further patellar dislocations occurred in three
knees, all in the instability group, one of which required further
surgery. The mean visual analogue scores for pain, and Lysholm and
Kujala scores improved significantly and were maintained at the
final follow-up (repeated measures, p = 0.000, intergroup differences
p = 0.449). Signs of maltracking were found in only a minority of
patients, with no difference between groups (p >
0.05). An increase
in patellofemoral osteoarthritis was seen in 16 knees (31%) with
a maximum of grade 2 on the Kellgren–Lawrence scale. The mean increase
in grades was 0.31 (0 to 2) and 0.41 (0 to 2) in the maltracking
and instability groups respectively (p = 0.2285) This self-centring tibial tubercle osteotomy provides good results
at ten years’ follow-up without inducing progressive osteoarthritis. 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:
The advent of computer-assisted knee replacement surgery has focused interest on the alignment of the components. However, there is confusion at times between the alignment of the limb as a whole and that of the components. The interaction between them is discussed in this article. Alignment is expressed relative to some reference axis or plane and measurements will vary depending on what is selected as the reference. The validity of different reference axes is discussed. Varying prosthetic alignment has direct implications for surrounding soft-tissue tension. In this context the interaction between alignment and soft-tissue balance is explored and the current knowledge of the relationship between alignment and outcome is summarised.