There has been debate about the role of unicompartmental knee replacement in the presence of radiologically identifiable
Aims. Patients with osteoarthritis of the knee commonly have degenerative
meniscal tears. Arthroscopic meniscectomy is frequently performed,
although the benefits are debatable. Recent studies have concluded
that there is no role for arthroscopic washout in osteoarthritis
of the knee. Our aim was to perform a systematic review to assess
the evidence for the efficacy of arthroscopic meniscectomy in patients
with meniscal tears and
Patellofemoral joint degeneration is often considered a contraindication to medial unicompartmental knee replacement. We examined the validity of this preconception using information gathered prospectively on the intra-operative status of the patellofemoral joint in 824 knees in 793 consecutive patients who underwent Oxford unicondylar knee replacement for anteromedial osteoarthritis. All operations were performed between January 1998 and September 2005. A five-point grading system classified degeneration of the patellofemoral joint from none to full-thickness cartilage loss. A subclassification of the presence or absence of any full-thickness cartilage loss was subsequently performed to test selected hypotheses. Outcome was evaluated independently by physiotherapists using the Oxford and the American Knee Society Scores with a minimum follow-up of one year. Full-thickness cartilage loss on the trochlear surface was observed in 100 of 785 knees (13%), on the medial facet of the patella in 69 of 782 knees (9%) and on the lateral facet in 29 of 784 knees (4%). Full-thickness cartilage loss at any location was seen in 128 knees (16%) and did not produce a significantly worse outcome than those with a normal or near-normal joint surface. The severity of the degeneration at any of the intra-articular locations also had no influence on outcome. We concluded that, provided there is not bone loss and grooving of the lateral facet, damage to the articular cartilage of the patellofemoral joint to the extent of full-thickness cartilage loss is not a contraindication to the Oxford mobile-bearing unicompartmental knee replacement.
Aims. It remains controversial whether patellofemoral joint pathology is a contraindication to lateral unicompartmental knee arthroplasty (UKA). This study aimed to evaluate the effect of preoperative radiological
We reviewed 183 patients who had undergone reconstruction of the anterior cruciate ligament. The incidence of meniscal tears and
We reviewed 87 patients who underwent revision reconstruction of the anterior cruciate ligament. The incidence of meniscal tears and
The purpose of this study was to evaluate the
long-term functional and radiological outcomes of arthroscopic removal
of unstable osteochondral lesions with subchondral drilling in the
lateral femoral condyle. We reviewed the outcome of 23 patients
(28 knees) with stage III or IV osteochondritis dissecans lesions
of the lateral femoral condyle at a mean follow-up of 14 years (10
to 19). The functional clinical outcomes were assessed using the Lysholm
score, which improved from a mean of 38.1 (. sd. 3.5) pre-operatively
to a mean of 87.3 (. sd. 5.4) at the most recent review (p
= 0.034), and the Tegner activity score, which improved from a pre-operative
median of 2 (0 to 3) to a median of 5 (3 to 7) at final follow-up
(p = 0.021). The radiological
Aim. Mesenchymal stem cells (MSCs) have several properties that may support their use as an early treatment option for osteoarthritis (OA). This study investigated the role of multiple injections of allogeneic bone marrow-derived stem cells (BMSCs) to alleviate the progression of osteoarthritic changes in the various structures of the mature rabbit knee in an anterior cruciate ligament (ACL)-deficient OA model. Materials and Methods. Two months after bilateral section of the ACL of Japanese white rabbits aged nine months or more, either phosphate buffered saline (PBS) or 1 x 10. 6. MSCs were injected into the knee joint in single or three consecutive doses. After two months, the articular cartilage and meniscus were assessed macroscopically, histologically, and immunohistochemically using collagen I and II. Results. Within the PBS injection (control group), typical progressive
Progressive
Adenosine, lidocaine, and Mg2+ (ALM) therapy exerts differential immuno-inflammatory responses in males and females early after anterior cruciate ligament (ACL) reconstruction (ACLR). Our aim was to investigate sex-specific effects of ALM therapy on joint tissue repair and recovery 28 days after surgery. Male (n = 21) and female (n = 21) adult Sprague-Dawley rats were randomly divided into ALM or Saline control treatment groups. Three days after ACL rupture, animals underwent ACLR. An ALM or saline intravenous infusion was commenced prior to skin incision, and continued for one hour. An intra-articular bolus of ALM or saline was also administered prior to skin closure. Animals were monitored to 28 days, and joint function, pain, inflammatory markers, histopathology, and tissue repair markers were assessed.Aims
Methods
We used single-photon emission computed tomography (SPECT) to determine the long-term risk of
The purpose of this study is to determine an individual’s age-specific prevalence of total knee arthroplasty (TKA) after cruciate ligament surgery, and to identify clinical and genetic risk factors associated with undergoing TKA. This study was a retrospective case-control study using the UK Biobank to identify individuals reporting a history of cruciate ligament surgery. Data from verbal history and procedural codes recorded through the NHS were used to identify instances of TKA. Patient clinical and genetic data were used to identify risk factors for progression from cruciate ligament surgery to TKA. Individuals without a history of cruciate ligament reconstruction were used for comparison.Aims
Methods
To identify unanswered questions about the prevention, diagnosis, treatment, and rehabilitation and delivery of care of first-time soft-tissue knee injuries (ligament injuries, patella dislocations, meniscal injuries, and articular cartilage) in children (aged 12 years and older) and adults. The James Lind Alliance (JLA) methodology for Priority Setting Partnerships was followed. An initial survey invited patients and healthcare professionals from the UK to submit any uncertainties regarding soft-tissue knee injury prevention, diagnosis, treatment, and rehabilitation and delivery of care. Over 1,000 questions were received. From these, 74 questions (identifying common concerns) were formulated and checked against the best available evidence. An interim survey was then conducted and 27 questions were taken forward to the final workshop, held in January 2023, where they were discussed, ranked, and scored in multiple rounds of prioritization. This was conducted by healthcare professionals, patients, and carers.Aims
Methods
To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration. The OCD lesion was created on the trochlear groove of left articular cartilage of femur per rat (40 rats in total). The experimental groups were Sham, OCD, and ESWT (0.25 mJ/mm2, 800 impulses, 4 Hz). The animals were euthanized at 2, 4, 8, and 12 weeks post-treatment, and histopathological analysis, micro-CT scanning, and immunohistochemical staining were performed for the specimens.Aims
Methods
Meniscal allograft transplantation (MAT) for patients with symptomatic meniscal loss has demonstrated good clinical results and survivorship. Factors that affect both functional outcome and survivorship have been reported in the literature. These are typically single-centre case series with relatively small numbers and conflicting results. Our aim was to describe an international, two-centre case series, and identify factors that affect both functional outcome and survival. We report factors that affect outcome on 526 patients undergoing MAT across two sites (one in the UK and one in Italy). Outcomes of interest were the Knee injury and Osteoarthritis Outcome Score four (KOOS4) at two years and failure rates. We performed multiple regression analysis to examine for factors affecting KOOS, and Cox proportional hazards models for survivorship.Aims
Methods
Platelet-rich plasma (PRP) intra-articular injections may provide a simple and minimally invasive treatment for early-stage knee osteoarthritis (OA). This has led to an increase in its adoption as a treatment for knee OA, although there is uncertainty about its efficacy and benefit. We hypothesized that patients with early-stage symptomatic knee OA who receive multiple PRP injections will have better clinical outcomes than those receiving single PRP or placebo injections. A double-blinded, randomized placebo-controlled trial was performed with three groups receiving either placebo injections (Normal Saline), one PRP injection followed by two placebo injections, or three PRP injections. Each injection was given one week apart. Outcomes were prospectively collected prior to intervention and then at six weeks, three months, six months, and 12 months post-intervention. Primary outcome measures were Knee Injury and Osteoarthritis Outcome Score (KOOS) and EuroQol five-dimension five-level index (EQ-5D-5L). Secondary outcomes included visual analogue scale for pain and patient subjective assessment of the injections.Aims
Methods
Previous studies support the important role of
vascular endothelial growth factor (VEGF) and syndecan-4 in the pathogenesis
of osteoarthritis (OA). Both VEGF and syndecan-4 are expressed by
chondrocytes and both are involved in the regulation of matrix metalloproteinase-3,
resulting in the activation of aggrecanase II (ADAMTS-5), which
is essential in the pathogenesis of OA. However, the relationship
between VEGF and syndecan-4 has not been established. As a pilot
study, we assayed the expression of VEGF and syndecan-4 in cartilage
samples and cultured chondrocytes from osteoarthritic knee joints
and analysed the relationship between these two factors. Specimens were collected from 21 female patients (29 knees) who
underwent total knee replacement due to severe medial OA of the
knee (Kellgren–Lawrence grade 4). Articular cartilage samples, obtained
from bone and cartilage excised during surgery, were analysed and
used for chondrocyte culture. We found that the levels of expression
of VEGF and syndecan-4 mRNA did not differ significantly between
medial femoral cartilage with severe
There is limited information on outcomes of revision ACL reconstruction (rACLR) in soccer (association football) athletes, particularly on return to sport and the rate of additional knee surgery. The purpose of this study was to report return to soccer after rACLR, and to test the hypothesis that patient sex and graft choice are associated with return to play and the likelihood of future knee surgery in soccer players undergoing rACLR. Soccer athletes enrolled in a prospective multicentre cohort were contacted to collect ancillary data on their participation in soccer and their return to play following rACLR. Information regarding if and when they returned to play and their current playing status was recorded. If they were not currently playing soccer, they were asked the primary reason they stopped playing. Information on any subsequent knee surgery following their index rACLR was also collected. Player demographic data and graft choice were collected from their baseline enrolment data at rACLR.Aims
Methods
We reviewed a single-surgeon series of 300 athletic patients who had undergone reconstruction of the anterior cruciate ligament in order to establish the relationship between the timing of the reconstruction and the incidence of meniscal and chondral pathology. The patients were divided into five groups according to the time from their injury to surgery as follows: less than two months, two to six months, six to 12 months, 12 to 18 months and more than 18 months. The presence of meniscal tears was recorded and chondral pathology was scored according to the system of the French Society of Arthroscopy. There was a significantly higher chance of a medial meniscal tear occurring in patients undergoing reconstruction after one year from their injury (odds ratio (7.99, p = 0.004). The odds of having a lateral meniscal tear did not change significantly with an increasing interval to reconstruction. The chance of patients developing
Anterior knee pain and/or radiological evidence of degeneration of the patellofemoral joint are considered to be contraindications to unicompartmental knee replacement. The aim of this study was to determine whether this is the case. Between January 2000 and September 2003, in 100 knees (91 patients) in which Oxford unicompartmental knee replacements were undertaken for anteromedial osteoarthritis, pre-operative anterior knee pain and the radiological status of the patellofemoral joint were defined using the Altman and Ahlback systems. Outcome was evaluated at two years with the Oxford knee score and the American Knee Society score. Pre-operatively 54 knees (54%) had anterior knee pain. The clinical outcome was independent of the presence or absence of pre-operative anterior knee pain.
We investigated the clinical and radiological outcome of trochleaplasty for recurrent patellar dislocation in association with trochlear dysplasia in 38 consecutive patients (45 knees) with a mean follow-up of 8.3 years (4 to 14). None had recurrence of dislocation after trochleaplasty. Post-operatively, patellofemoral pain, present pre-operatively in only 35 knees, became worse in 15 (33.4%), remained unchanged in four (8.8%) and improved in 22 (49%). Four knees which had no pain pre-operatively (8.8%) continued to have no pain. A total of 33 knees were available for radiological assessment. Post-operatively, all but two knees (93.9%) had correction of trochlear dysplasia radiologically but
To determine the relationship between articular cartilage status and clinical outcomes after medial opening-wedge high tibial osteotomy (MOHTO) for medial compartmental knee osteoarthritis at intermediate follow-up. We reviewed 155 patients (155 knees) who underwent MOHTO from January 2008 to December 2016 followed by second-look arthroscopy with a mean 5.3-year follow-up (2.0 to 11.7). Arthroscopic findings were assessed according to the International Cartilage Repair Society (ICRS) Cartilage Repair Assessment (CRA) grading system. Patients were divided into two groups based on the presence of normal or nearly normal quality cartilage in the medial femoral condyle: good (second-look arthroscopic) status (ICRS grade I or II; n = 70), and poor (second-look arthroscopic) status (ICRS grade III or IV; n = 85) groups at the time of second-look arthroscopy. Clinical outcomes were assessed using the International Knee Documentation Committee (IKDC) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 36-Item Short Form survey.Aims
Methods
The aim of this study was to compare the clinical outcomes of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) during the first six weeks and at one year postoperatively. A per protocol analysis of 76 patients, 43 of whom underwent TKA and 34 of whom underwent bi-UKA, was performed from a prospective, single-centre, randomized controlled trial. Diaries kept by the patients recorded pain, function, and the use of analgesics daily throughout the first week and weekly between the second and sixth weeks. Patient-reported outcome measures (PROMs) were compared preoperatively, and at three months and one year postoperatively. Data were also compared longitudinally and a subgroup analysis was conducted, stratified by preoperative PROM status.Aims
Methods
This study used an artificial neural network (ANN) model to determine the most important pre- and perioperative variables to predict same-day discharge in patients undergoing total knee arthroplasty (TKA). Data for this study were collected from the National Surgery Quality Improvement Program (NSQIP) database from the year 2018. Patients who received a primary, elective, unilateral TKA with a diagnosis of primary osteoarthritis were included. Demographic, preoperative, and intraoperative variables were analyzed. The ANN model was compared to a logistic regression model, which is a conventional machine-learning algorithm. Variables collected from 28,742 patients were analyzed based on their contribution to hospital length of stay.Aims
Methods
The aim of this study was to compare ten-year longitudinal healthcare costs and revision rates for patients undergoing unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). The Humana database was used to compare 2,383 patients undergoing UKA between 2007 and 2009, who were matched 1:1 from a cohort of 63,036 patients undergoing primary TKA based on age, sex, and Elixhauser Comorbidity Index. Medical and surgical complications were tracked longitudinally for one year following surgery. Rates of revision surgery and cumulative mean healthcare costs were recorded for this period of time and compared between the cohorts.Aims
Methods
In the last decade, interest in partial knee arthroplasties and bicruciate retaining total knee arthroplasties has increased. In addition, patient-related outcomes and functional results such as range of movement and ambulation may be more promising with less invasive procedures such as bicompartmental arthroplasty (BCA). The purpose of this study is to evaluate clinical and radiological outcomes after a third-generation patellofemoral arthroplasty (PFA) combined with a medial or lateral unicompartmental knee arthroplasty (UKA) at mid- to long-term follow-up. A total of 57 procedures were performed. In 45 cases, a PFA was associated with a medial UKA and, in 12, with a lateral UKA. Patients were followed with validated patient-reported outcome measures (Oxford Knee Score (OKS), EuroQol five-dimension questionnaire (EQ-5D), EuroQoL Visual Analogue Scale (EQ-VAS)), the Knee Society Score (KSS), the Forgotten Joint Score (FJS), and radiological analysis.Aims
Methods
This study aimed to identify the tibial component and femoral component coronal angles (TCCAs and FCCAs), which concomitantly are associated with the best outcomes and survivorship in a cohort of fixed-bearing, cemented, medial unicompartmental knee arthroplasties (UKAs). We also investigated the potential two-way interactions between the TCCA and FCCA. Prospectively collected registry data involving 264 UKAs from a single institution were analyzed. The TCCAs and FCCAs were measured on postoperative radiographs and absolute angles were analyzed. Clinical assessment at six months, two years, and ten years was undertaken using the Knee Society Knee score (KSKS) and Knee Society Function score (KSFS), the Oxford Knee Score (OKS), the 36-Item Short-Form Health Survey questionnaire (SF-36), and range of motion (ROM). Fulfilment of expectations and satisfaction was also recorded. Implant survivorship was reviewed at a mean follow-up of 14 years (12 to 16). Multivariate regression models included covariates, TCCA, FCCA, and two-way interactions between them. Partial residual graphs were generated to identify angles associated with the best outcomes. Kaplan-Meier analysis was used to compare implant survivorship between groups.Aims
Methods
We evaluated the outcome of partial lateral meniscectomy of 31 knees in 29 patients whose knees were otherwise normal. The mean follow-up was 10.3 years. According to the Lysholm score, 14 knees were rated as excellent, four as good, five as fair and eight as poor, with a mean score of 80.5 points. Radiologically, only one lateral compartment was classified as grade 0, eight as grade 1, nine as grade 2, 11 as grade 3, and two as grade 4 according to Tapper and Hoover. No significant (p <
0.05) correlation was found between the amount of tissue resected and the subjective, clinical and radiological outcome. Although early results of lateral meniscectomy may be satisfactory, we have demonstrated that in the long term there was a high incidence of
We have carried out a prospective, longitudinal 30-year review of 95 adolescents who underwent total meniscectomy in one knee, and have compared the results with those observed 13 years earlier. All the medical records were scrutinised. Of the 63 patients reviewed clinically, 47 reported decreased sporting activity, although subjective satisfaction rose by 3% to 71%. The scores on the WOMAC osteoarthritis index differed significantly between patients grouped by subjective global assessment. Satisfactory function scores increased from 48% to 60%. In the 53 patients consenting to bilateral radiography of the knee, the incidence of narrowing of the articular cartilage in the operated knee increased significantly between the reviews (19% to 36%). Progression of
Limited evidence is available on mid-term outcomes of robotic-arm assisted (RA) partial knee arthroplasty (PKA). Therefore, the purpose of this study was to evaluate mid-term survivorship, modes of failure, and patient-reported outcomes of RA PKA. A retrospective review of patients who underwent RA PKA between June 2007 and August 2016 was performed. Patients received a fixed-bearing medial or lateral unicompartmental knee arthroplasty (UKA), patellofemoral arthroplasty (PFA), or bicompartmental knee arthroplasty (BiKA; PFA plus medial UKA). All patients completed a questionnaire regarding revision surgery, reoperations, and level of satisfaction. Knee Injury and Osteoarthritis Outcome Scores (KOOS) were assessed using the KOOS for Joint Replacement Junior survey.Aims
Methods
In a prospective randomised trial 76 knees with isolated
We treated 90 patients with an isolated injury to the anterior cruciate ligament (ACL) by reconstruction using a patellar tendon autograft and interference screw fixation. Of these, 82 (91%) were available for review at 24 months. Two grafts and two contralateral ACLs had ruptured during sport and there was one case of atraumatic graft resorption. Using the assessment of the International Knee Documentation Committee (IKDC), 86% of the remaining patients were normal or nearly normal. The median Lysholm knee score was 95/100 and 84% of patients were participating in moderate to strenuous activity. All had grade-0 or grade-1 Lachman, pivot-shift and anterior-drawer tests. Measurement with the KT1000 arthrometer gave a side-to-side difference of <
3 mm of anterior tibial displacement in 90%. Sixty-six radiographs were IKDC grade A and one was grade B. Pain on kneeling was present in 31% and graft site pain in 44%. At 24 months after operation all patients had excellent knee stability, a high rate of return to sport and minimal radiological evidence of
The objectives of this study were to assess the effect of anterior cruciate ligament (ACL) resection on flexion-extension gaps, mediolateral soft tissue laxity, maximum knee extension, and limb alignment during primary total knee arthroplasty (TKA). This prospective study included 140 patients with symptomatic knee osteoarthritis undergoing primary robotic-arm assisted TKA. All operative procedures were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess study outcomes pre- and post-ACL resection with knee extension and 90° knee flexion. This study included 76 males (54.3%) and 64 females (45.7%) with a mean age of 64.1 years (SD 6.8) at time of surgery. Mean preoperative hip-knee-ankle deformity was 6.1° varus (SD 4.6° varus).Aims
Methods
The natural history of spontaneous osteonecrosis of the medial tibial plateau remains controversial and incomplete. We have studied 21 patients (aged between 53 and 77 years) with clinical and scintigraphic features of spontaneous osteonecrosis of the medial tibial plateau who were observed prospectively for at least three years (37 months to 8.5 years). The mean duration of follow-up was 5.6 years. The mean duration of symptoms at presentation was 4.7 weeks (3 days to 12 weeks). Radiographs of the affected knee at the first visit were normal in 15 patients and mildly arthritic in six. The characteristic radiographic lesion of osteonecrosis was noted at presentation in five of the mildly arthritic knees and during the evolution of the disease in eight of the radiographically normal knees. During the follow-up, subchondral sclerosis of the affected medial tibial plateau was noted in 16 knees. There are three distinct patterns of outcome: 1) acute extensive collapse of the medial tibial plateau in two knees within three months of onset; 2) rapid progression to varying degrees of osteoarthritis in 12 knees, in eight within a year, in all within two years and deterioration of the pre-existing osteoarthritis in three; and 3) complete resolution in four knees, two of which were normal at presentation and two mildly osteoarthritic. The two patients with acute extensive collapse and three who had rapid progression to severe osteoarthritis required total knee arthroplasty. We conclude that osteonecrosis of the medial tibial plateau progresses in most cases to significant
Altered alignment and biomechanics are thought to contribute to the progression of osteoarthritis (OA) in the native compartments after medial unicompartmental knee arthroplasty (UKA). The aim of this study was to evaluate the bone activity and remodelling in the lateral tibiofemoral and patellofemoral compartment after medial mobile-bearing UKA. In total, 24 patients (nine female, 15 male) with 25 medial Oxford UKAs (13 left, 12 right) were prospectively followed with sequential 99mTc-hydroxymethane diphosphonate single photon emission CT (SPECT)/CT preoperatively and at one and two years postoperatively, along with standard radiographs and clinical outcome scores. The mean patient age was 62 years (40 to 78) and the mean body mass index (BMI) was 29.7 kg/m2 (23.6 to 42.2). Mean osteoblastic activity was evaluated using a tracer localization scheme with volumes of interest (VOIs). Normalized mean tracer values were calculated as the ratio between the mean tracer activity in a VOI and background activity in the femoral diaphysis.Aims
Patients and Methods
The aim of this study was to report the outcome of femoral condylar fresh osteochondral allografts (FOCA) with concomitant realignment osteotomy with a focus on graft survivorship, complications, reoperation, and function. We identified 60 patients (16 women, 44 men) who underwent unipolar femoral condylar FOCA with concomitant realignment between 1972 and 2012. The mean age of the patients was 28.9 years (10 to 62) and the mean follow-up was 11.4 years (2 to 35). Failure was defined as conversion to total knee arthroplasty, revision allograft, or graft removal. Clinical outcome was evaluated using the modified Hospital for Special Surgery (mHSS) score.Aims
Patients and Methods
There is little literature about total knee arthroplasty (TKA) after distal femoral osteotomy (DFO). Consequently, the purpose of this study was to analyze the outcomes of TKA after DFO, with particular emphasis on: survivorship free from aseptic loosening, revision, or any re-operation; complications; radiological results; and clinical outcome. We retrospectively reviewed 29 patients (17 women, 12 men) from our total joint registry who had undergone 31 cemented TKAs after a DFO between 2000 and 2012. Their mean age at TKA was 51 years (22 to 76) and their mean body mass index 32 kg/m2 (20 to 45). The mean time between DFO and TKA was ten years (2 to 20). The mean follow-up from TKA was ten years (2 to 16). The prostheses were posterior-stabilized in 77%, varus-valgus constraint (VVC) in 13%, and cruciate-retaining in 10%. While no patient had metaphyseal fixation (e.g. cones or sleeves), 16% needed a femoral stem.Aims
Patients and Methods
The aim of this study was to determine and compare the congruency of the articular surface contact area of the patellofemoral joint (PFJ) during both active and passive movement of the knee with the use of an MRI mapping technique in both the stable and unstable PFJ. A prospective case-control MRI imaging study of patients with a history of PFJ instability and a control group of volunteers without knee symptoms was performed. The PFJs were imaged with the use of an MRI scan during both passive and active movement from 0° through to 40° of flexion. The congruency through measurement of the contact surface area was mapped in 5-mm intervals on axial slices. In all, 40 patients were studied. The case group included 31 patients with symptomatic patellofemoral instability and the control group of nine asymptomatic volunteers. The ages were well matched between the case and control groups. The mean age was 25 years (16 to 42; Aims
Patients and Methods
Primary (or spontaneous) and secondary osteonecrosis of the knee
can lead to severe joint degeneration, for which either total or
unicompartmental arthroplasty may be considered. However, there
are limited studies analyzing outcomes of unicompartmental knee arthroplasties
(UKAs) for osteonecrosis involving an isolated compartment of the
knee. The aims of this study were to analyze outcomes of UKAs for
osteonecrosis with specific focus on 1) survivorship free of any
revision or reoperation, 2) risk factors for failure, 3) clinical outcomes,
and 4) complications. A total of 45 patients underwent 46 UKAs for knee osteonecrosis
between 2002 and 2014 at our institution (The Mayo Clinic, Rochester,
Minnesota). Twenty patients (44%) were female; the mean age of the
patients was 66 years, and mean body mass index (BMI) was 31 kg/m2. Of
the 46 UKAs, 44 (96%) were medial UKAs, and 35 (76%) were fixed-bearing
design. Mean mechanical axis postoperatively was 1.5° varus (0°
to 5° varus); 41 UKAs (89%) were performed for primary osteonecrosis.
Mean follow-up was five years (2 to 12)Aims
Patients and Methods
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
The aim of this study was to investigate the long-term clinical
and radiological outcome of patients who suffer recurrent injuries
to the anterior cruciate ligament (ACL) after reconstruction and
require revision surgery. From a consecutive series of 200 patients who underwent primary
reconstruction following rupture of the ACL, we identified 36 who
sustained a further rupture, 29 of whom underwent revision surgery.
Patients were reviewed prospectively at one, two, seven, 15 and
about 20 years after their original surgery. Primary outcome measures
were the number of further ruptures, the posterior tibial slope
(PTS), and functional and radiological outcomes. These were compared
with a gender and age matched cohort of patients who underwent primary
ACL reconstruction only.Aims
Patients and Methods
The lack of effective treatment for cartilage defects has prompted investigations using tissue engineering techniques for their regeneration and repair. The success of tissue-engineered repair of cartilage may depend on the rapid and efficient adhesion of transplanted cells to a scaffold. Our aim in this study was to repair full-thickness defects in articular cartilage in the weight-bearing area of a porcine model, and to investigate whether the CD44 monoclonal antibody biotin-avidin (CBA) binding technique could provide satisfactory tissue-engineered cartilage. Cartilage defects were created in the load-bearing region of the lateral femoral condyle of mini-type pigs. The defects were repaired with traditional tissue-engineered cartilage, tissue-engineered cartilage constructed with the biotin-avidin (BA) technique, tissue-engineered cartilage constructed with the CBA technique and with autologous cartilage. The biomechanical properties, Western blot assay, histological findings and immunohistochemical staining were explored.Objectives
Methods
We aimed to investigate factors related to the technique of medial
opening wedge high tibial osteotomy which might predispose to the
development of a lateral hinge fracture. A total of 71 patients with 82 osteotomies were included in the
study. Their mean age was 62.9 years (37 to 80). The classification
of the type of osteotomy was based on whether it extended beyond
the fibular head. The level of the osteotomy was classified according
to the height of its endpoint.Aims
Patients and Methods
Static radiostereometric analysis (RSA) using implanted markers is considered the most accurate system for the evaluation of prosthesis migration. By using CT bone models instead of markers, combined with a dynamic RSA system, a non-invasive measurement of joint movement is enabled. This method is more accurate than current 3D skin marker-based tracking systems. The purpose of this study was to evaluate the accuracy of the CT model method for measuring knee joint kinematics in static and dynamic RSA using the marker method as the benchmark. Bone models were created from CT scans, and tantalum beads were implanted into the tibia and femur of eight human cadaver knees. Each specimen was secured in a fixture, static and dynamic stereoradiographs were recorded, and the bone models and marker models were fitted to the stereoradiographs.Objectives
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 MPFL may impart the lowest risk to the physis. If minor growth
remains image intensifier guided placement of femoral intraosseous
fixation may impart a small, but acceptable, risk to the physis. This paper presents and discusses the literature relating to
adolescent instability and provides a framework for management of
these patients. Cite this article:
The aim of the current study was to analyse the effects of posterior cruciate ligament (PCL) deficiency on forces of the posterolateral corner structure and on tibiofemoral (TF) and patellofemoral (PF) contact force under dynamic-loading conditions. A subject-specific knee model was validated using a passive flexion experiment, electromyography data, muscle activation, and previous experimental studies. The simulation was performed on the musculoskeletal models with and without PCL deficiency using a novel force-dependent kinematics method under gait- and squat-loading conditions, followed by probabilistic analysis for material uncertain to be considered.Objectives
Methods
It is widely held that most Baker’s cysts resolve after treatment
of the intra-articular knee pathology. The present study aimed to
evaluate the fate of Baker’s cysts and their associated symptoms
after total knee arthroplasty (TKA). In this prospective cohort study, 102 patients with (105 were
included, however three were lost to follow-up) an MRI-verified
Baker’s cyst, primary osteoarthritis and scheduled for TKA were
included. Ultrasound was performed to evaluate the existence and
the gross size of the cyst before and at one year after TKA. Additionally,
associated symptoms of Baker's cyst were recorded pre- and post-operatively.Aims
Patients and Methods
The interest in unicompartmental knee arthroplasty (UKA) for
medial osteoarthritis has increased rapidly but the long-term follow-up
of the Oxford UKAs has yet to be analysed in non-designer centres.
We have examined our ten- to 15-year clinical and radiological follow-up
data for the Oxford Phase III UKAs. Between January 1999 and January 2005 a total of 138 consecutive
Oxford Phase III arthroplasties were performed by a single surgeon
in 129 patients for medial compartment osteoarthritis (71 right
and 67 left knees, mean age 72.0 years (47 to 91), mean body mass
index 28.2 (20.7 to 52.2)). Both clinical data and radiographs were
prospectively recorded and obtained at intervals. Of the 129 patients,
32 patients (32 knees) died, ten patients (12 knees) were not able
to take part in the final clinical and radiological assessment due
to physical and mental conditions, but via telephone interview it
was confirmed that none of these ten patients (12 knees) had a revision
of the knee arthroplasty. One patient (two knees) was lost to follow-up.Aims
Patients and Methods
The aim of this study was to review the early
outcome of the Femoro-Patella Vialla (FPV) joint replacement. A
total of 48 consecutive FPVs were implanted between December 2007
and June 2011. Case-note analysis was performed to evaluate the
indications, operative histology, operative findings, post-operative
complications and reasons for revision. The mean age of the patients
was 63.3 years (48.2 to 81.0) and the mean follow-up was
25.0 months (6.1 to 48.9). Revision was performed in seven (14.6%)
at a mean of 21.7 months, and there was one re-revision. Persistent
pain was observed in three further patients who remain unrevised.
The reasons for revision were pain due to progressive tibiofemoral
disease in five, inflammatory arthritis in one, and patellar fracture following
trauma in one. No failures were related to the implant or the technique.
Trochlear dysplasia was associated with a significantly lower rate
of revision (5.9% Focal patellofemoral osteoarthritis secondary to trochlear dysplasia
should be considered the best indication for patellofemoral replacement.
Standardised radiological imaging, with MRI to exclude overt tibiofemoral
disease should be part of the pre-operative assessment, especially
for the non-dysplastic knee. Cite this article:
The significance of weight in the indications
for unicompartmental knee replacement (UKR) is unclear. Our hypothesis was
that weight does not affect the long-term rate of survival of UKRs. We undertook a retrospective study of 212 UKRs at a mean follow-up
of 12 years (7 to 22). The patients were distributed according to
body mass index (BMI; <
The ten-year rates of survival were similar in the two weight
subgroups (≥ 82 kg: 93.5% (95% confidence interval (CI) 66.5 to
96.3); <
82 kg: 92.5% (95% CI 82.5 to 94.1)) and also in the
two BMI subgroups (≥ 30 kg/m2: 92% (95% CI 82.5 to 95.3);
<
30 kg/m2: 94% (95% CI 78.4 to 95.9)). Multimodal
regression analysis revealed that weight plays a part in reducing
the risk of revision with a relative risk of 0.387, although this
did not reach statistical significance (p = 0.662). The results
relating weight and BMI to the clinical outcome were not statistically
significant. Thus, this study confirms that weight does not influence
the long-term rate of survival of UKR. Cite this article:
The purpose of this study was to report the outcome
of ‘isolated’ anterior cruciate ligament (ACL) ruptures treated with
anatomical endoscopic reconstruction using hamstring tendon autograft
at a mean of 15 years (14.25 to 16.9). A total of 100 consecutive
men and 100 consecutive women with ‘isolated’ ACL rupture underwent
four-strand hamstring tendon reconstruction with anteromedial portal
femoral tunnel drilling and interference screw fixation by a single
surgeon. Details were recorded pre-operatively and at one, two,
seven and 15 years post-operatively. Outcomes included clinical
examination, subjective and objective scoring systems, and radiological
assessment. At 15 years only eight of 118 patients (7%) had moderate
or severe osteo-arthritic changes (International Knee Documentation
Committee Grades C and D), and 79 of 152 patients (52%) still performed
very strenuous activities. Overall graft survival at 15 years was
83% (1.1% failure per year). Patients aged <
18 years at the
time of surgery and patients with >
2 mm of laxity at one year had
a threefold increase in the risk of suffering a rupture of the graft
(p = 0.002 and p = 0.001, respectively). There was no increase in
laxity of the graft over time. ACL reconstructive surgery in patients with an ‘isolated’ rupture
using this technique shows good results 15 years post-operatively
with respect to ligamentous stability, objective and subjective
outcomes, and does not appear to cause osteoarthritis.
Medium-term survivorship of the Oxford phase
3 unicompartmental knee replacement (UKR) has not yet been established
in an Asian population. We prospectively evaluated the outcome of
400 phase 3 Oxford UKRs in 320 Korean patients with a mean age at
the time of operation of 69 years (48 to 82). The mean follow-up
was 5.2 years (1 to 10). Clinical and radiological assessment was
carried out pre- and post-operatively. At five years, the mean Knee
Society knee and functional scores had increased significantly from
56.2 (30 to 91) pre-operatively to 87.2 (59 to 98) (p = 0.034) and
from 59.2 (30 to 93) to 88.3 (50 to 100) (p = 0.021), respectively.
The Oxford knee score increased from a mean of 25.8 (12 to 39) pre-operatively
to 39.8 (25 to 58) at five years (p = 0.038). The ten-year survival
rate was 94% (95% confidence interval 90.1 to 98.0). A total of
14 UKRs (3.5%) required revision. The most common reason for revision
was dislocation of the bearing in 12 (3%). Conversion to a total
knee replacement was required in two patients who developed osteoarthritis
of the lateral compartment. This is the largest published series of UKR in Korean patients.
It shows that the mid-term results after a minimally invasive Oxford
phase 3 UKR can yield satisfactory clinical and functional results
in this group of patients.
Focal femoral inlay resurfacing has been developed
for the treatment of full-thickness chondral defects of the knee. This
technique involves implanting a defect-sized metallic or ceramic
cap that is anchored to the subchondral bone through a screw or
pin. The use of these experimental caps has been advocated in middle-aged
patients who have failed non-operative methods or biological repair
techniques and are deemed unsuitable for conventional arthroplasty
because of their age. This paper outlines the implant design, surgical
technique and biomechanical principles underlying their use. Outcomes
following implantation in both animal and human studies are also reviewed. Cite this article:
We evaluated the long-term outcome of isolated endoscopically-assisted posterior cruciate ligament reconstruction in 26 patients using hamstring tendon autografts after failure of conservative management. At ten years after surgery the mean International Knee Documentation Committee subjective knee score was 87 ( At ten years endoscopic reconstruction of the posterior cruciate ligament with hamstring tendon autograft is effective in reducing knee symptoms. Of the series, 22 patients underwent radiological assessment for the development of osteoarthritis using the Kellgren-Lawrence grading scale. In four patients, grade 2 changes with loss of joint space was observed and another four patients showed osteophyte formation with moderate joint space narrowing (grade 3). These findings compared favourably with non-operatively managed injuries of the posterior cruciate ligament. This procedure for symptomatic patients with posterior cruciate ligament laxity who have failed conservative management offers good results.
We continued a prospective longitudinal follow-up
study of 53 remaining patients who underwent open total meniscectomy
as adolescents and who at that time had no other intra-articular
pathology of the knee. Their clinical, radiological and patient-reported
outcomes are described at a mean follow-up of 40 years (33 to 50).
The cohort of patients who had undergone radiological evaluation
previously after 30 years were invited for clinical examination,
radiological evaluation and review using two patient-reported outcome
measures. A total of seven patients (13.2%) had already undergone total
knee replacement at the time of follow-up. A significant difference
was observed between the operated and non-operated knee in terms
of range of movement and osteoarthritis of the tibiofemoral joint,
indicating a greater than fourfold relative risk of osteoarthritis
at 40 years post-operatively. All patients were symptomatic as defined
by the Knee Injury and Osteoarthritis Outcome Score. This study represents the longest follow-up to date and it can
be concluded that meniscectomy leads to symptomatic osteoarthritis
of the knee later in life, with a resultant 132-fold increase in
the rate of total knee replacement in comparison to their geographical
and age-matched peers.
This review considers the surgical treatment
of displaced fractures involving the knee in elderly, osteoporotic patients.
The goals of treatment include pain control, early mobilisation,
avoidance of complications and minimising the need for further surgery.
Open reduction and internal fixation (ORIF) frequently results in
loss of reduction, which can result in post-traumatic arthritis
and the occasional conversion to total knee replacement (TKR). TKR
after failed internal fixation is challenging, with modest functional
outcomes and high complication rates. TKR undertaken as treatment
of the initial fracture has better results to late TKR, but does
not match the outcome of primary TKR without complications. Given
the relatively infrequent need for late TKR following failed fixation,
ORIF is the preferred management for most cases. Early TKR can be
considered for those patients with pre-existing arthritis, bicondylar
femoral fractures, those who would be unable to comply with weight-bearing restrictions,
or where a single definitive procedure is required.
There is little evidence examining the relationship between anatomical landmarks, radiological placement of the tunnels and long-term clinical outcomes following anterior cruciate ligament (ACL) reconstruction. The aim of this study was to investigate the reproducibility of intra-operative landmarks for placement of the tunnels in single-bundle reconstruction of the ACL using four-strand hamstring tendon autografts. Isolated reconstruction of the ACL was performed in 200 patients, who were followed prospectively for seven years with use of the International Knee Documentation Committee forms and radiographs. Taking 0% as the anterior and 100% as the posterior extent, the femoral tunnel was a mean of 86% ( The use of intra-operative landmarks resulted in reproducible placement of the tunnels and an excellent clinical outcome seven years after operation. Vertical inclination was associated with increased rotational instability and degenerative radiological changes, while rupture of the graft was associated with posterior placement of the tibial tunnel. If the osseous tunnels are correctly placed, single-bundle reconstruction of the ACL adequately controls both anteroposterior and rotational instability.
From a search of MRI reports on knees, 20 patients were identified with evidence of early anteromedial osteoarthritis without any erosion of bone and a control group of patients had an acute rupture of the anterior cruciate ligament. The angle formed between the extension and flexion facets of the tibia, which is known as the extension facet angle, was measured on a sagittal image at the middle of the medial femoral condyle. The mean extension facet angle in the control group was 14° (3° to 25°) and was unrelated to age (Spearman’s rank coefficient, p = 0.30, r = 0.13). The mean extension facet angle in individuals with MRI evidence of early anteromedial osteoarthritis was 19° (13° to 26°, SD 4°). This difference was significant (Mann-Whitney U test, p <
0.001). A wide variation in the extension facet angle was found in the normal control knees and an association between an increased extension facet angle and MRI evidence of early anteromedial osteoarthritis. Although a causal link has not been demonstrated, we postulate that a steeper extension facet angle might increase the duration of loading on the extension facet during the stance phase of gait, and that this might initiate failure of the articular cartilage.
We reviewed 5086 patients with a mean age of
30 years (9 to 69) undergoing primary reconstruction of the anterior cruciate
ligament (ACL) in order to determine the incidence of secondary
pathology with respect to the time between injury and reconstruction.
There was an increasing incidence of medial meniscal tears and chondral damage,
but not lateral meniscal tears, with increasing intervals before
surgery. The chances of requiring medial meniscal surgery was increased
by a factor of two if ACL reconstruction was delayed more than five
months, and increased by a factor of six if surgery was delayed
by >
12 months. The effect of delaying surgery on medial meniscal injury
was also pronounced in the patients aged <
17 years, where a
delay of five to 12 months doubled the odds of medial meniscal surgery
(odds ratio (OR) 2.0, p = 0.001) and a delay of >
12 months quadrupled
the odds (OR 4.3, p = 0.001). Increasing age was associated with
a greater odds of chondral damage (OR 4.6, p = 0.001) and medial meniscal
injury (OR 2.9, p = 0.001), but not lateral meniscal injury. The
gender split (3251 men, 1835 women) revealed that males had a greater
incidence of both lateral (34% (n = 1114) Cite this article:
The outcome of arthroscopic medial release of 255 knees in 173 patients for varying grades of osteoarthritis involving the medial compartment is reported. All operations were performed by a single surgeon between January 2001 and May 2003. The Knee Society score for pain and the patient’s subjective satisfaction were used for the outcome evaluation. Overall, satisfactory outcome was reported for 197 knees (77.3%) and the mean Knee Society score for pain improved from 17.6 (95% confidence interval, 16.7 to 18.5), pre-operatively to 39.4 (95% confidence interval, 37.9 to 41.1) (p <
0.001). There were minor manageable complications of persistent effusion in 16 knees and prolonged wound discomfort in 11. In total, 15 of the 21 knees with poor results were converted to total knee replacements and two other patients (three knees) were offered this option after a mean period of 16 months. Based on these observations arthroscopic medial release is an effective treatment for osteoarthritis of the medial compartment of the knee joint and can be expected to reduce the pain in the majority of patients for at least four years post-operatively.
We systematically reviewed the published literature
on the complications of closing wedge high tibial osteotomy for
the treatment of unicompartmental osteoarthritis of the knee. Publications
were identified using the Cochrane Library, MEDLINE, EMBASE and
CINAHL databases up to February 2012. We assessed randomised (RCTs), controlled
group clinical (CCTs) trials, case series in publications associated
with closing wedge osteotomy of the tibia in patients with osteoarthritis
of the knee and finally a Cochrane review. Many of these trials
included comparative studies (opening wedge
A total of 445 consecutive primary total knee
replacements (TKRs) were followed up prospectively at six and 18 months
and three, six and nine years. Patients were divided into two groups:
non-obese (body mass index (BMI) <
30 kg/m2) and obese
(BMI ≥ 30 kg/m2). The obese group was subdivided into
mildly obese (BMI 30 to 35 kg/m2) and highly obese (BMI ≥ 35
kg/m2) in order to determine the effects of increasing
obesity on outcome. The clinical data analysed included the Knee
Society score, peri-operative complications and implant survival.
There was no difference in the overall complication rates or implant
survival between the two groups. Obesity appears to have a small but significant adverse effect
on clinical outcome, with highly obese patients showing lower function
scores than non-obese patients. However, significant improvements
in outcome are sustained in all groups nine years after TKR. Given
the substantial, sustainable relief of symptoms after TKR and the low
peri-operative complication and revision rates in these two groups,
we have found no reason to limit access to TKR in obese patients.
Radiological assessment of total and unicompartmental
knee replacement remains an essential part of routine care and follow-up.
Appreciation of the various measurements that can be identified
radiologically is important. It is likely that routine plain radiographs
will continue to be used, although there has been a trend towards
using newer technologies such as CT, especially in a failing knee,
where it provides more detailed information, albeit with a higher
radiation exposure. The purpose of this paper is to outline the radiological parameters
used to evaluate knee replacements, describe how these are measured
or classified, and review the current literature to determine their
efficacy where possible.
This prospective study used magnetic resonance imaging to record sagittal plane tibiofemoral kinematics before and after anterior cruciate ligament reconstruction using autologous hamstring graft. Twenty patients with anterior cruciate ligament injuries, performed a closed-chain leg-press while relaxed and against a 150 N load. The tibiofemoral contact patterns between 0° to 90° of knee flexion were recorded by magnetic resonance scans. All measurements were performed pre-operatively and repeated at 12 weeks and two years. Following reconstruction there was a mean passive anterior laxity of 2.1 mm (
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 management of nonunion following high tibial osteotomy by total knee replacement (TKR) has been reported previously. We have extended the treatment to embrace cases with an infected high tibial osteotomy by performing an initial debridement with a period of antibiotic treatment followed by TKR. We have reviewed the results of seven knees in six patients with a mean follow-up of 40.5 months (20 to 57) after the staged TKR. At the latest follow-up, all the pseudarthroses had healed and there had been no recurrence of infection. The mean Hospital for Special Surgery knee score improved from 51.2 (35 to 73) to a mean of 91.7 (84 to 98) at final review. Management of nonunion following high tibial osteotomy with a TKR can be extended to infected cases when treated in two stages with a debridement and antibiotic therapy prior to TKR.
The purpose of this study was to examine the effect of posterior
cruciate ligament (PCL) retention, PCL recession, and PCL excision
during cruciate-retaining total knee replacement. A total of 3018 anatomic graduated component total knee replacements
were examined; 1846 of these retained the PCL, 455 PCLs were partially
recessed, and in 717 the PCL was completely excised from the back
of the tibia.Objectives
Methods
We retrospectively reviewed the operative treatment carried out between 1988 and 1994 of eight patients with habitual patellar dislocation. In four the condition was bilateral. All patients had recurrent dislocation with severe functional disability. The surgical technique involved distal advancement of the patella by complete mobilisation of the patellar tendon, lateral release and advancement of vastus medialis obliquus. The long-term results were assessed radiologically, clinically and functionally using the Lysholm knee score, by an independent observer. The mean age at operation was 10.3 years (7 to 14) with a mean follow-up of 13.5 years (11 to 16). One patient required revision. At the latest follow-up, all patellae were stable and knees functional with a mean Lysholm knee score of 98 points (95 to 100). In those aged younger than ten years at operation there was a statistically significant improvement in the sulcus angle at the latest follow-up (Student’s This technique offers a satisfactory treatment for the immature patient presenting with habitual patellar dislocation associated with patella alta. If performed early, we believe that remodelling of the shallow trochlea may occur, adding intrinsic patellofemoral stability.
Our aims were to map the tibial footprint of the posterior cruciate ligament (PCL) using MRI in patients undergoing PCL-preserving total knee replacement, and to document the disruption of this footprint as a result of the tibial cut. In 26 consecutive patients plain radiography and MRI of the knee were performed pre-operatively, and plain radiography post-operatively. The lower margin of the PCL footprint was located a mean of 1 mm (−10 to 8) above the upper aspect of the fibular head. The mean surface area was 83 mm2 (49 to 142). One-third of patients (8 of 22) had tibial cuts made below the lowest aspect of the PCL footprint (complete removal) and one-third (9 of 22) had cuts extending into the footprint (partial removal). The remaining patients (5 of 22) had footprints unaffected by the cuts, keeping them intact. Our study highlights the wide variation in the location of the tibial PCL footprint when referenced against the fibula. Proximal tibial cuts using conventional jigs resulted in the removal of a significant portion, if not all of the PCL footprint in most of the patients in our study. Our findings suggest that when performing PCL-retaining total knee replacement the tibial attachment of the PCL is often removed.
We report a retrospective analysis of the results of combined arthroscopically-assisted posterior cruciate ligament reconstruction and open reconstruction of the posterolateral corner in 19 patients with chronic (three or more months) symptomatic instability and pain in the knee. All the operations were performed between 1996 and 2003 and all the patients were assessed pre- and post-operatively by physical examination and by applying three different ligament rating scores. All also had weight-bearing radiographs, MR scans and an examination under anaesthesia and arthroscopy pre-operatively. The posterior cruciate ligament reconstruction was performed using an arthroscopically-assisted single anterolateral bundle technique and the posterolateral corner structures were reconstructed using an open Larson type of tenodesis. The mean follow up was 66.8 months (24 to 110). Pre-operatively, all the patients had a grade III posterior sag according to Clancy and demonstrated more than 20° of external rotation compared with the opposite normal knee on the Dial test. Post-operatively, seven patients (37%) had no residual posterior sag, 11 (58%) had a grade I posterior sag and one (5%) had a grade II posterior sag. In five patients (26%) there was persistent minimal posterolateral laxity. The Lysholm score improved from a mean of 41.2 (28 to 53) to 76.5 (57 to 100) (p = 0.0001) and the Tegner score from a mean of 2.6 (1 to 4) to 6.4 (4 to 9) (p = 0.0001). We conclude that while a combined reconstruction of chronic posterior cruciate ligament and posterolateral corner instability improves the function of the knee, it does not restore complete stability.
Twenty patients underwent simultaneous bilateral medial unicompartmental knee arthroplasty. Pre-operative hip-knee-ankle alignment and valgus stress radiographs were used to plan the desired post-operative alignment of the limb in accordance with established principles for unicompartmental arthroplasty. In each patient the planned alignment was the same for both knees. Overall, the mean planned post-operative alignment was to 2.3° of varus (0° to 5°). The side and starting order of surgery were randomised, using conventional instrumentation for one knee and computer-assisted surgery for the opposite side. The mean variation between the pre-operative plan and the achieved correction in the navigated and the non-navigated limb was 0.9° ( Assessment of lower limb alignment in the non-navigated group revealed that 12 (60%) were within ± 2° of the pre-operative plan, compared to 17 (87%) of the navigated cases. Computer-assisted surgery significantly improves the post-operative alignment of medial unicompartmental knee arthroplasty compared to conventional techniques in patients undergoing bilateral simultaneous arthroplasty. Improved alignment after arthroplasty is associated with better function and increased longevity.
We identified a series of 128 patients who had unilateral open reconstruction of the anterior cruciate ligament (ACL) by a single surgeon between 1993 and 2000. In all, 79 patients were reviewed clinically and radiologically eight to 15 years after surgery. Assessment included measurement of the Lysholm and Tegner scores, the ACL quality-of-life score and the Short Form-12 score, as well as the International Knee Documentation Committee clinical assessment, measurement of laxity by the KT-1000 arthrometer, a single-leg hop test and standardised radiography of both knees using the uninjured knee as a control. Of the injured knees, 46 (57%) had definite radiological evidence of osteoarthritis (Kellgren-Lawrence grade 2 or 3), with a mean difference between the injured and non-injured knees of 1.2 grades. The median ACL quality-of-life score was 80 (interquartile range (IQR) 60 to 90), the Lysholm score 84 (IQR 74 to 95), the Short Form-12 physical component score 54 (IQR 49 to 56) and the mean Hop Index 0.94 (0.52 to 1.52). In total 58 patients were graded as normal, 20 as nearly normal and one as abnormal on the KT-1000 assessment and pivot-shift testing. Taking the worst-case scenario of assuming all non-attenders (n = 48), two septic failures and one identified unstable knee found at review to be failures, the failure rate was 40%. Only two of the patients reviewed stated that they would not have similar surgery again. Open reconstruction of the ACL gives good, durable functional results, but with a high rate of radiologically evident osteoarthritis.
Intra-articular resection of bone with soft-tissue balancing and total knee replacement (TKR) has been described for the treatment of patients with severe osteoarthritis of the knee associated with an ipsilateral malunited femoral fracture. However, the extent to which deformity in the sagittal plane can be corrected has not been addressed. We treated 12 patients with severe arthritis of the knee and an extra-articular malunion of the femur by TKR with intra-articular resection of bone and soft-tissue balancing. The femora had a mean varus deformity of 16° (8° to 23°) in the coronal plane. There were seven recurvatum deformities with a mean angulation of 11° (6° to 15°) and five antecurvatum deformities with a mean angulation of 12° (6° to 15°). The mean follow-up was 93 months (30 to 155). The median Knee Society knee and function scores improved from 18.7 (0 to 49) and 24.5 (10 to 50) points pre-operatively to 93 (83 to 100) and 90 (70 to 100) points at the time of the last follow-up, respectively. The mean mechanical axis of the knee improved from 22.6° of varus (15° to 27° pre-operatively to 1.5° of varus (3° of varus to 2° of valgus) at the last follow-up. The recurvatum deformities improved from a mean of 11° (6° to 15°) pre-operatively to 3° (0° to 6°) at the last follow-up. The antecurvatum deformities in the sagittal plane improved from a mean of 12° (6° to 16°) pre-operatively to 4.4° (0° to 8°) at the last follow-up. Apart from varus deformities, TKR with intra-articular bone resection effectively corrected the extra-articular deformity of the femur in the presence of antecurvatum of up to 16° and recurvatum of up to 15°.
Haemophilia is an x-linked inherited bleeding disorder which can cause severe arthropathy. We have reviewed the results of 70 primary total knee replacements (TKR) performed in 57 haemophilic patients between 1983 and 2007. The functional results were assessed using the Hospital for Special Surgery (HSS) knee scoring system and Kaplan-Meier survivorship analysis. Six patients died. HSS scores were available for 60 TKRs at a mean follow-up of 9.2 years (2 to 23); 57 (95%) had good or excellent results. Deep infection was recorded in one patient. Kaplan-Meier analysis using infection and aseptic loosening as endpoints showed the survival rate at 20 years to be 94.0%. A reduction in infection, spontaneous haemarthrosis and improvement in the quality of life were noted to justify surgery in our series of patients with a mean age of 43 (25 to 70). We have found that using the latest techniques of continuous infusion of clotting Factor have significantly helped to reduce the complication rates and have achieved results which match those of the non-haemophilic population undergoing TKR.
Isolated patellofemoral osteoarthritis can be a disabling disease. When conservative treatment fails, surgical options can be unpredictable and may be considered too aggressive for middle-aged and active people. We analysed the clinical and radiological results of a new coronal osteotomy involving thinning of the patella in a selected group of patients with isolated patellofemoral osteoarthritis. Since 1991, 31 patients (35 knees) have been treated, of whom 34 were available for follow-up at a mean of 9.1 years. The Knee Society Score, the Patellar score and the Short-form-36 questionnaire were used for clinical evaluation. We also examined the radiological features to confirm bone consolidation and assess the progression of osteoarthritis. A significant improvement in the functional scores and radiological parameters was noted. All patients except one were satisfied with the operation. Radiological progression of the patellofemoral osteoarthritis was slowed but radiological femorotibial osteoarthritis progressed in 23 (65%) cases, with a total knee replacement becoming necessary in four cases without technical problems in resurfacing the patella. We compared the results with other forms of surgical treatment reported in the literature. This treatment offers good clinical and radiological results, presenting an alternative method of managing patellofemoral osteoarthritis.
We compared the incidence and severity of complications during and after closing- and opening-wedge high tibial osteotomy used for the treatment of varus arthritis of the knee, and identified the risk factors associated with the development of complications. In total, 104 patients underwent laterally based closing-wedge and 90 medial opening-wedge high tibial osteotomy between January 1993 and December 2006. The characteristics of each group were similar. All the patients were followed up for more than 12 months. We assessed the outcome using the Hospital for Special Surgery knee score, and recorded the complications. Age, gender, obesity (body mass index >
27.5 kg/m2), the type of osteotomy (closing The mean Hospital for Special Surgery score in the closing and opening groups improved from 73.4 (54 to 86) to 91.8 (81 to 100) and from 73.8 (56 to 88) to 93 (84 to 100), respectively. The incidence of complications overall and of major complications in both groups was not significantly different (p = 0.20 overall complication, p = 0.29 major complication). Logistic regression analysis adjusting for obesity and the pre-operative mechanical axis showed that obesity remained a significant independent risk factor (odds ratio = 3.23) of a major complication after high tibial osteotomy. Our results suggest that the opening-wedge high tibial osteotomy can be an alternative treatment option for young patients with medial compartment osteoarthritis and varus deformity.
We describe injuries to the posterior root of the medial meniscus in patients with spontaneous osteonecrosis of the medial compartment of the knee. We identified 30 consecutive patients with spontaneous osteonecrosis of the medial femoral condyle. The radiographs and MR imaging were reviewed. We found tears of the posterior root of the medial meniscus in 24 patients (80%). Of these, 15 were complete and nine were partial. Complete tears were associated with >
3 mm of meniscal extrusion. Neither the presence of a root tear nor the volume of the osteonecrotic lesion were associated with age, body mass index (BMI), gender, side affected, or knee alignment. The grade of osteoarthritis was associated with BMI. Although tears of the posterior root of the medial meniscus were frequently present in patients with spontaneous osteonecrosis of the knee, this does not prove cause and effect. Further study is warranted.
We retrospectively reviewed 35 cemented unicompartmental knee replacements performed for medial unicompartmental osteoarthritis of the knee in 31 patients ≤50 years old (mean 46, 31 to 49). Patients were assessed clinically and radiologically using the Knee Society scores at a mean follow-up of 9.7 years (5 to 16) and survival at 12 years was calculated. The mean Knee Society Function Score improved from 54 points (25 to 64) pre-operatively to 89 (80 to 100) post-operatively (p <
0.0001). Six knees required revision, four for polyethylene wear treated with an isolated exchange of the tibial insert, one for aseptic loosening and one for progression of osteoarthritis. The 12-year survival according to Kaplan-Meier was 80.6% with revision for any reason as the endpoint. Despite encouraging clinical results, polyethylene wear remains a major concern affecting the survival of unicompartmental knee replacement in patients younger than 50.
The records of patients aged 50 years or over who underwent primary reconstruction of the anterior cruciate ligament between 1990 and 2002 were reviewed. There were 35 knees in 34 patients that met the inclusion criteria. The mean age of the patients was 57 years (50 to 66) and the mean clinical follow-up was for 72 months (25 to 173). A total of 23 knees were reconstructed with patellar tendon allograft, and 12 with patellar tendon autograft. The mean pre-operative knee extension was 1° (−5° to 10°) and flexion was 129° (125° to 150°) and at follow-up these values were 0° (−5° to 5°) and 135° (120° to 150°), respectively. Pre-operatively there were 31 knees (89%) with a Lachman grade 2+ or 3+. Post-operatively, 33 knees (94%) were Lachman grade 0 or 1+. The mean pre- and post-operative International Knee Documentation Committee scores were 39 (23 to 72) and 90 (33 to 100) respectively. The mean pre- and post-operative Lysholm scores were 50 (18 to 68) and 92 (28 to 100) respectively and the mean University of California Los Angeles activity scores were 8.5 before injury (4 to 10), 4.3 (3 to 6) after injury and 8.3 (4 to 10) post-operatively. There were three graft failures (8.6%) requiring revision. We conclude that reconstruction of the anterior cruciate ligament in carefully-selected patients aged 50 years or over can achieve similar results to those in younger patients, with no increased risk of complications.
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.
We investigated the three-dimensional morphological differences of the articular surface of the femoral trochlea in patients with recurrent dislocation of the patella and a normal control group using three-dimensional computer models. There were 12 patients (12 knees) and ten control subjects (ten knees). Three-dimensional computer models of the femur, including the articular cartilage, were created. Evaluation was performed on the shape of the articular surface, focused on its convexity, and the proximal and mediolateral distribution of the articular cartilage of the femoral trochlea. The extent of any convexity, and the proximal distribution of the articular cartilage, expressed as the height, were shown by the angles about the transepicondylar axis. The mediolateral distribution of the articular cartilage was assessed by the location of the medial and lateral borders of the articular cartilage. The mean extent of convexity was 24.9° Our findings therefore quantitatively demonstrated differences in the shape and distribution of the articular cartilage on the femoral trochlea between patients with dislocation of the patella and normal subjects.
We compared the results ten years after an inverted V-shaped high tibial osteotomy with those of a historical series of conventional closing-wedge osteotomies. The closing-wedge series consisted of 56 knees in 51 patients with a mean follow-up of 11 years (10 to 15). The inverted V-shaped osteotomy was evaluated in 48 knees in 43 patients at a mean follow-up of 14 years (10 to 19). All the patients were scored using the Japanese Orthopaedic Association rating scale for osteoarthritis of the knee and radiological assessment. The pre-operative grade of osteoarthritis was similar in both groups. Post-operatively, the knee function score was graded as satisfactory in 63% (35) of the closing-wedge group but in 89% (43) of the inverted V-shaped osteotomy group. Post-operative radiological examination showed that delayed union and loss of correction occurred more often after a closing-wedge osteotomy than after an inverted V-shaped procedure. Our study suggests that the inverted V-shaped osteotomy may offer more dependable long-term results than traditional closing-wedge osteotomy.
The results of 41 consecutive total knee replacements performed on morbidly obese patients with a body mass index >
40 kg/m2, were compared with a matched group of 41 similar procedures carried out in non-obese patients (body mass index <
30 kg/m2). The groups were matched for age, gender, diagnosis, type of prosthesis, laterality and pre-operative Knee Society Score. We prospectively followed up the patients for a mean of 38.5 months (6 to 66). No patients were lost to follow-up. At less than four years after operation, the results were worse in the morbidly obese group compared with the non-obese, as demonstrated by inferior Knee Society Scores (mean knee score 85.7 and 90.5 respectively, p = 0.08; mean function score 75.6 and 83.4, p = 0.01), a higher incidence of radiolucent lines on post-operative radiographs (29% and 7%, respectively, p = 0.02), a higher rate of complications (32% and 0%, respectively, p = 0.001) and inferior survivorship using revision and pain as end-points (72.3% and 97.6%, respectively, p = 0.02). Patients with a body mass index >
40 kg/m2 should be advised to lose weight prior to total knee replacement and to maintain weight reduction. They should also be counselled regarding the inferior results which may occur if they do not lose weight before surgery.
We have quantitatively documented the insertion geometry of the main stabilising structures of the posterolateral corner of the knee in 34 human cadavers. The lateral collateral ligament inserted posterior (4.6 mm, The ligaments had a consistent pattern of insertion and, despite the variation between specimens, the standard deviations were less than the typical size of drill hole used in reconstruction of the posterolateral corner. The data provided in this study can be used in the anatomical repair and reconstruction of this region of the knee.
We used three-dimensional movement analysis by computer modelling of knee flexion from 0° to 50° in 14 knees in 12 patients with recurrent patellar dislocation and in 15 knees in ten normal control subjects to compare the The patients had greater values of spin from 20° to 50°, while there were no statistically significant differences in flexion and tilt. The patients also had greater percentage patellar shift from 0° to 50°, percentage tubercle shift at 0° and 10° and patellar inclination from 0° to 50° with a smaller oval-shaped contact area from 20° to 50° moving downwards on the lateral facet. Patellar movement analysis using a three-dimensional computer model is useful to clearly demonstrate differences between patients with recurrent dislocation of the patella and normal control subjects.
We compared peri-prosthetic bone mineral density between identical cemented and cementless LCS rotating platform total knee arthroplasties. Two matched cohorts had dual energy x-ray absorptiometry scans two years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic bone mineral density. The knee that was not operated on was also scanned to enable the calculation of a relative bone mineral density difference. Oxford Knee and American Knee Society scores were comparable in the two cohorts. Statistical analysis revealed no significant difference in absolute, or relative peri-prosthetic bone mineral density with respect to the method of fixation. However, the femoral peri-prosthetic bone mineral density and relative bone mineral density difference were significantly decreased, irrespective of the method of fixation, particularly in the anterior distal portion of the femur, with a mean reduction in relative bone mineral density difference of 27%. There was no difference in clinical outcome between the cemented and cementless LCS total knee arthroplasty. However, both produce stress-shielding around the femoral implants. This leads us to question the use of more expensive cementless total knee components.