The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous.Aims
Methods
The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous.Aims
Methods
Tibial tubercle osteotomy (TTO) facilitates surgical exposure and protects the extensor mechanism during revision total knee arthroplasty (rTKA). The purpose of this study was to determine the rates of bony union, complications, and reoperations following TTO during rTKA, to assess the functional outcomes of rTKA with TTO at two years’ minimum follow-up, and to identify the risk factors of failure. Between January 2010 and September 2020, 695 rTKAs were performed and data were entered into a prospective database. Inclusion criteria were rTKAs with concomitant TTO, without extensor mechanism allograft, and a minimum of two years’ follow-up. A total of 135 rTKAs were included, with a mean age of 65 years (SD 9.0) and a mean BMI of 29.8 kg/m2 (SD 5.7). The most frequent indications for revision were infection (50%; 68/135), aseptic loosening (25%; 34/135), and stiffness (13%; 18/135). Patients had standardized follow-up at six weeks, three months, six months, and annually thereafter. Complications and revisions were evaluated at the last follow-up. Functional outcomes were assessed using the Knee Society Score (KSS) and range of motion.Aims
Methods
Recognized anatomic variations that lead to patella instability include patella alta and trochlea dysplasia. Lateralization of the extensor mechanism relative to the trochlea is often considered to be a contributing factor; however, controversy remains as to the degree this contributes to instability and how this should be measured. As the tibial tuberosity-trochlear groove (TT-TG) is one of most common imaging measurements to assess lateralization of the extensor mechanism, it is important to understand its strengths and weaknesses. Care needs to be taken while interpreting the TT-TG value as it is affected by many factors. Medializing tibial tubercle osteotomy is sometimes used to correct the TT-TG, but may not truly address the underlying anatomical problem. This review set out to determine whether the TT-TG distance sufficiently summarizes the pathoanatomy, and if this assists with planning of surgery in patellar instability. Cite this article:
The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective. The OBC and the patellotrochlear index were used as part of the Oswestry Patellotrochlear Algorithm (OPTA) to guide the surgical treatment of patients with patellar instability. Patients were assigned to one of four treatment groups: medial patellofemoral ligament reconstruction (MPFLr); MPFLr + tibial tubercle distalization (TTD); trochleoplasty; or trochleoplasty + TTD. A prospective analysis of a longitudinal patellofemoral database was performed. Between 2012 and 2018, 202 patients (233 knees) with a mean age of 24.2 years (SD 8.1), with recurrent patellar instability were treated by two fellowship-trained consultant sports/knee surgeons at The Robert Jones and Agnes Hunt Orthopaedic Hospital. Clinical efficacy of each treatment group was assessed by Kujala, International Knee Documentation Committee (IKDC), and EuroQol five-dimension questionnaire (EQ-5D) scores at baseline, and up to 60 months postoperatively. Their safety was assessed by complication rate and requirement for further surgery. The pattern of clinical outcome over time was analyzed using mixed regression modelling.Aims
Methods
Joint registries classify all further arthroplasty procedures to a knee with an existing partial arthroplasty as revision surgery, regardless of the actual procedure performed. Relatively minor procedures, including bearing exchanges, are classified in the same way as major operations requiring augments and stems. A new classification system is proposed to acknowledge and describe the detail of these procedures, which has implications for risk, recovery, and health economics. Classification categories were proposed by a surgical consensus group, then ranked by patients, according to perceived invasiveness and implications for recovery. In round one, 26 revision cases were classified by the consensus group. Results were tested for inter-rater reliability. In round two, four additional cases were added for clarity. Round three repeated the survey one month later, subject to inter- and intrarater reliability testing. In round four, five additional expert partial knee arthroplasty surgeons were asked to classify the 30 cases according to the proposed revision partial knee classification (RPKC) system.Aims
Methods
Evaluating musculoskeletal conditions of the lower limb and understanding the pathophysiology of complex bone kinematics is challenging. Static images do not take into account the dynamic component of relative bone motion and muscle activation. Fluoroscopy and dynamic MRI have important limitations. Dynamic CT (4D-CT) is an emerging alternative that combines high spatial and temporal resolution, with an increased availability in clinical practice. 4D-CT allows simultaneous visualization of bone morphology and joint kinematics. This unique combination makes it an ideal tool to evaluate functional disorders of the musculoskeletal system. In the lower limb, 4D-CT has been used to diagnose femoroacetabular impingement, patellofemoral, ankle and subtalar joint instability, or reduced range of motion. 4D-CT has also been used to demonstrate the effect of surgery, mainly on patellar instability. 4D-CT will need further research and validation before it can be widely used in clinical practice. We believe, however, it is here to stay, and will become a reference in the diagnosis of lower limb conditions and the evaluation of treatment options. Cite this article:
The Oswestry-Bristol Classification (OBC) was recently described as an MRI-based classification tool for the femoral trochlear. The authors demonstrated better inter- and intraobserver agreement compared to the Dejour classification. As the OBC could potentially provide a very useful MRI-based grading system for trochlear dysplasia, it was the aim to determine the inter- and intraobserver reliability of the classification system from the perspective of the non-founder. Two orthopaedic surgeons independently assessed 50 MRI scans for trochlear dysplasia and classified each according to the OBC. Both observers repeated the assessments after six weeks. The inter- and intraobserver agreement was determined using Cohen’s kappa statistic and S-statistic nominal and linear weights.Aims
Methods
To evaluate the donor site morbidity and tendon morphology after harvesting whole length, full-thickness peroneus longus tendon (PLT) proximal to the lateral malleolus for ligament reconstructions or tendon transfer. A total of 21 eligible patients (mean age 34.0 years (standard deviation (SD) 11.2); mean follow-up period 31.8 months (SD 7.7), and 12 healthy controls (mean age, 26.8 years (SD 5.9) were included. For patients, clinical evaluation of the donor ankle was performed preoperatively and postoperatively. Square hop test, ankle strength assessment, and MRI of distal calf were assessed bilaterally in the final follow-up. The morphological symmetry of peroneal tendons bilaterally was evaluated by MRI in healthy controls.Aims
Methods
Trochlear dysplasia is a significant risk factor for patellofemoral instability. The Dejour classification is currently considered the standard for classifying trochlear dysplasia, but numerous studies have reported poor reliability on both plain radiography and MRI. The severity of trochlear dysplasia is important to establish in order to guide surgical management. We have developed an MRI-specific classification system to assess the severity of trochlear dysplasia, the Oswestry-Bristol Classification (OBC). This is a four-part classification system comprising normal, mild, moderate, and severe to represent a normal, shallow, flat, and convex trochlear, respectively. The purpose of this study was to assess the inter- and intraobserver reliability of the OBC and compare it with that of the Dejour classification. Four observers (two senior and two junior orthopaedic surgeons) independently assessed 32 CT and axial MRI scans for trochlear dysplasia and classified each according to the OBC and the Dejour classification systems. Assessments were repeated following a four-week interval. The inter- and intraobserver agreement was determined by using Fleiss’ generalization of Cohen’s kappa statistic and S-statistic nominal and linear weights.Aims
Methods
The aim of this study was to evaluate cartilaginous patellotrochlear congruence and patellofemoral alignment parameters after deepening trochleoplasty in severe trochlear dysplasia. The study group comprised 20 patients (two male, 18 female; mean age 24 years (16 to 39)) who underwent deepening trochleoplasty and medial patellofemoral ligament (MPFL) reconstruction for the treatment of recurrent lateral patellar dislocation due to severe trochlear dysplasia (Dejour type B to D). Pre- and postoperative MRI investigations of the study group were compared with MRI data of 20 age- and gender-matched control patients (two male, 18 female; mean age 27 years (18 to 44)) regarding the patellotrochlear contact ratio, patellotrochlear contact area, posterior patellar edge-trochlear groove ratio, and patellar tilt.Aims
Patients and Methods
The aim of this study was to investigate the changes in femoral
trochlear morphology following surgical correction of recurrent
patellar dislocation associated with trochlear dysplasia in children. A total of 23 patients with a mean age of 9.6 years (7 to 11)
were included All had bilateral recurrent patellar dislocation associated
with femoral trochlear dysplasia. The knee with traumatic dislocation
at the time of presentation or that had dislocated most frequently
was treated with medial patellar retinacular plasty (Group S). The
contralateral knee served as a control and was treated conservatively
(Group C). All patients were treated between October 2008 and August
2013. The mean follow-up was 48.7 months (43 to 56). Axial CT scans
were undertaken in all patients to assess the trochlear morphological
characteristics on a particular axial image which was established
at the point with the greatest epicondylar width based on measurements
preoperatively and at the final follow-up.Aims
Patients and Methods
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
Patellar instability most frequently presents
during adolescence. Congenital and infantile dislocation of the
patella is a distinct entity from adolescent instability and measurable
abnormalities may be present at birth. In the normal patellofemoral
joint an increase in quadriceps angle and patellar height are matched
by an increase in trochlear depth as the joint matures. Adolescent
instability may herald a lifelong condition leading to chronic disability
and arthritis. Restoring normal anatomy by trochleoplasty, tibial tubercle transfer
or medial patellofemoral ligament (MPFL) reconstruction in the young
adult prevents further instability. Although these techniques are
proven in the young adult, they may cause growth arrest and deformity
where the physis is open. A vigorous non-operative strategy may
permit delay of surgery until growth is complete. Where non-operative
treatment has failed a modified MPFL reconstruction may be performed
to maintain stability until physeal closure permits anatomical reconstruction.
If significant growth remains an extraosseous reconstruction of
the
The December 2015 Children’s orthopaedics Roundup360 looks at: Paediatric femoral fractures: a single incision nailing?; Lateral condylar fractures: open or percutaneous?; Forearm refracture: the risks; Tibial spine fractures; The child’s knee in MRI; The mechanics of SUFE; Idiopathic clubfoot
The August 2015 Children’s orthopaedics Roundup360 looks at: Learning the Pavlik; MRI and patellar instability; Cerebral palsy and hip dysplasia; ‘Pick your poison’: elastic nailing under the spotlight; Club feet and surgery; Donor site morbidity in vascularised fibular grafting; Cartilage biochemistry with hip dysplasia; SUFE and hip decompression: a good option?
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 October 2013 Children’s orthopaedics Roundup360 looks at: Half a century of Pavlik treatment; Step away from the child!: trends in fracture management; Posterolateral rotatory elbow instability in children; Osteochondral lesions undiagnosed in patellar dislocations; Oral bisphosphonates in osteogenesis imperfecta; Crossed or parallel pins in supracondylar fractures?; Not too late nor too early: getting epiphysiodesis right; Fixation of supramalleolar osteotomies.
Medial patellofemoral ligament (MPFL) reconstruction
is used to treat patellar instability and recurrent patellar dislocation.
Anatomical studies have found the
Hypermobility is an acknowledged risk factor
for patellar instability. In this case control study the influence
of hypermobility on clinical outcome following medial patellofemoral
ligament (MPFL) reconstruction for patellar instability was studied. A total of 25 patients with hypermobility as determined by the
Beighton criteria were assessed and compared with a control group
of 50 patients who were matched for age, gender, indication for
surgery and degree of trochlear dysplasia. The patients with hypermobility
had a Beighton Score of ≥ 6; the control patients had a score of <
4. All patients underwent MPFL reconstruction performed using semitendinosus
autograft and a standardised arthroscopically controlled technique.
The mean age of the patients was 25 years (17 to 49) and the mean
follow-up was 15 months (6 to 30). Patients with hypermobility had a significant improvement in
function following surgery, with reasonable rates of satisfaction,
perceived improvement, willingness to repeat and likelihood of recommendation.
Functional improvements were significantly less than in control
patients (p <
0.01). Joint hypermobility is not a contraindication to
We report a prospective analysis of clinical
outcome in patients treated with medial patellofemoral ligament
(MPFL) reconstruction using an autologous semitendinosus graft.
The technique includes superolateral portal arthroscopic assessment
before and after graft placement to ensure correct graft tension
and patellar tracking before fixation. Between October 2005 and
October 2010, a total of 201 consecutive patients underwent 219 procedures.
Follow-up is presented for 211 procedures in 193 patients with a
mean age of 26 years (16 to 49), and mean follow-up of 16 months
(6 to 42). Indications were atraumatic recurrent patellar dislocation
in 141 patients, traumatic recurrent dislocation in 50, pain with
subluxation in 14 and a single dislocation with persistent instability
in six. There have been no recurrent dislocations/subluxations.
There was a statistically significant improvement between available pre-
and post-operative outcome scores for 193 patients (all p <
0.001).
Female patients with a history of atraumatic recurrent dislocation
and all patients with history of previous surgery had a significantly
worse outcome (all p <
0.05). The indication for surgery, degree
of dysplasia, associated patella alta, time from primary dislocation
to surgery and evidence of associated cartilage damage at operation
did not result in any significant difference in outcome. This series adds considerably to existing evidence that MPFL
reconstruction is an effective surgical procedure for selected patients
with patellofemoral instability.
The August 2012 Children’s orthopaedics Roundup360 looks at: whether 3D-CT gives a better idea of coverage than plain radiographs; forearm fractures after trampolining accidents; forearm fractures and the Rush pin; the fractured distal radius; elastic stable intramedullary nailing for long-bone fractures; aponeurotic recession for the equinus foot; the torn medial patellofemoral ligament and the adductor tubercle; slipped capital femoral epiphysis; paediatric wrist arthroscopy; and Pirani scores and clubfoot.
The June 2012 Children’s orthopaedics Roundup360 looks at; open reduction for DDH; growing rod instrumentation for scoliosis; acute patellar dislocation; management of the relapsed clubfoot; clubfoot in Iran; laughing gas and fracture manipulation; vascularised periosteal fibular grafting for nonunion; slipped upper femoral epiphysis; intramedullary leg lengthening and orthopaedic imaging and defensive medicine.
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.
The tensile strength of the medial patellofemoral ligament (MPFL), and of surgical procedures which reconstitute it, are unknown. Ten fresh cadaver knees were prepared by isolating the patella, leaving only the
