Unicompartmental knee arthroplasty (UKA) is a potential treatment
for isolated bone on bone osteoarthritis when limited to a single
compartment. The risk for revision of UKA is three times higher
than for total knee arthroplasty (TKA). The aim of this review was
to discuss the different revision options after UKA failure. A search was performed for English language articles published
between 2006 and 2016. After reviewing titles and abstracts, 105
papers were selected for further analysis. Of these, 39 papers were
deemed to contain clinically relevant data to be included in this review.Objectives
Materials and Methods
A majority of patients present with varus alignment and predominantly medial compartment disease. The secret of success in osteoarthritis (OA) treatment is patient selection and patient specific treatment. Different wear patterns have been described and that knowledge should be utilised in modern knee surgery. In case of isolated anteromedial OA, unicompartmental knee arthroplasty (UKA) should be one of the therapeutic options available to the knee surgeon. The discussion not to offer a UKA to patients is based on the fear of the surgeon not being able to identify the right patient and not being able to perform the surgery accurately. The common modes of failure for UKA, which are dislocation or overcorrection leading to disease progression, can be avoided with a fixed bearing implant. Wear can probably be avoided with newer polyethylenes and avoidance of overstuffing in flexion of the knee. Revision for unexplained pain and unknown causes should disappear once surgeons understand persistent pain after surgery much better than they do today. The choice in favor of UKA is a choice of function over survivorship, a choice for reduced comorbidity and lower mortality. Many of the common problems in TKA are not an issue in UKA. Component overhang, decreased posterior offset, changed joint line height, gap mismatch, flexion gap instability, lift off and paradoxical motion hardly exist in UKA if the replacement is performed according to resurfacing principles with respect for the native knee anatomy. New technologies like navigation, PSI and robotics will help with alignment and component positioning. Surgeon education and training should allow over time UKA to be performed by all of us.
One of the arguments in favor of unicompartmental knee arthroplasty (UKA) is the possibility of an easier revision. Especially if UKA is considered as an early intervention allowing bridging until total knee arthroplasty (TKA) is necessary at later age. If indeed primary TKA results can be obtained at time of revision, UKA becomes a real indication to postpone TKA until a later age. For obtaining primary TKA results, a primary knee should be indicated for the revision. This is possible if the UKA cuts were conservative and within the resection level of a primary TKA. Furthermore bone loss should be contained and either be resected or easily solved with substituting techniques compatible with a primary TKA. Finally, the primary implant utilised should allow a full interchangeability of the tibial and femoral sizes. This allows a lower tibial cut during the revision, often leading to a smaller size but interchangeability avoids downsizing the femur and creating flexion gap instability. If the UKA to TKA revision asks for stems, bone substitutions, joint line changes and more constraint, the primary result will not be obtained. Therefore it is important to select a bone preserving UKA system that allows for conservative bone cuts and avoids deep keel preparations. UKA to TKA with primary components and without gap mismatches or joint line changes leads to excellent outcome.
Patellofemoral arthroplasty (PFA) can give excellent results in well-selected patients. Axial alignment has been extensively studied in this type of surgery. However because there is no distal femoral cut, coronal alignment in PFA is less well known. The position of the patellofemoral component decides the varus or valgus alignment of the implant. Coronal alignment in PFA (PFJ-Gender, Zimmer, Warsaw, US) is determined by the anterior condylar anatomy and features an important variance influencing coronal alignment.Introduction
Hypothesis
Patient satisfaction after total hip arthroplasty (THA) has been reported to be significantly better than after total knee arthroplasty (TKA). The same has been observed for the capacity to forget during daily life activities about the operated joint. Recently a new patient reported outcome score, the Forgotten Joint Score (FJS-12) a twelve item questionaire, has been used to evaluate postoperative outcome in joint arthroplasty. A better FJS-12 score was measured in THA than in TKA objectivating the intuitive feeling that the joint was more forgotten in THA than in TKA. A higher preoperative FJS-12 score is the reason for a higher postoperative FJS-12 score in THA compared to TKAIntroduction
Hypothesis
Total knee arthroplasty (TKA) is a major orthopaedic
intervention. The length of a patient's stay has been progressively
reduced with the introduction of enhanced recovery protocols: day-case
surgery has become the ultimate challenge. This narrative review shows the potential limitations of day-case
TKA. These constraints may be social, linked to patient’s comorbidities,
or due to surgery-related adverse events (e.g. pain, post-operative
nausea and vomiting, etc.). Using patient stratification, tailored surgical techniques and
multimodal opioid-sparing analgesia, day-case TKA might be achievable
in a limited group of patients. The younger, male patient without
comorbidities and with an excellent social network around him might
be a candidate. Demographic changes, effective recovery programmes and less invasive
surgical techniques such as unicondylar knee arthroplasty, may increase
the size of the group of potential day-case patients. The cost reduction achieved by day-case TKA needs to be balanced
against any increase in morbidity and mortality and the cost of
advanced follow-up at a distance with new technology. These factors
need to be evaluated before adopting this ultimate ‘fast-track’
approach. Cite this article:
The patient with a painful arthritic knee awaiting
total knee arthroplasty (TKA) requires a multidisciplinary approach.
Optimal control of acute post-operative pain and the prevention
of chronic persistent pain remains a challenge. The aim of this
paper is to evaluate whether stratification of patients can help
identify those who are at particular risk for severe acute or chronic
pain. Intense acute post-operative pain, which is itself a risk factor
for chronic pain, is more common in younger, obese female patients
and those suffering from central pain sensitisation. Pre-operative
pain, in the knee or elsewhere in the body, predisposes to central
sensitisation. Pain due to osteoarthritis of the knee may also trigger
neuropathic pain and may be associated with chronic medication like
opioids, leading to a state of nociceptive sensitisation called
‘opioid-induced hyperalgesia’. Finally, genetic and personality
related risk factors may also put patients at a higher risk for
the development of chronic pain. Those identified as at risk for chronic pain would benefit from
specific peri-operative management including reduction in opioid
intake pre-operatively, the peri-operative use of antihyperalgesic
drugs such as ketamine and gabapentinoids, and a close post-operative
follow-up in a dedicated chronic pain clinic. Cite this article:
We conducted a meta-analysis, including randomised
controlled trials (RCTs) and cohort studies, to examine the effect
of patient-specific instruments (PSI) on radiological outcomes after
total knee replacement (TKR) including: mechanical axis alignment
and malalignment of the femoral and tibial components in the coronal,
sagittal and axial planes, at a threshold of >
3º from neutral.
Relative risks (RR) for malalignment were determined for all studies
and for RCTs and cohort studies separately. Of 325 studies initially identified, 16 met the eligibility criteria,
including eight RCTs and eight cohort studies. There was no significant
difference in the likelihood of mechanical axis malalignment with
PSI We conclude that PSI does not improve the accuracy of alignment
of the components in TKR compared with conventional instrumentation. Cite this article:
Three important objectives in knee arthroplasty are improving outcome, providing stability and obtaining correct alignment. Alignment has always been described either by anatomically measured alignment (short films, Knee Society Radiologic Score) or by mechanically measured alignment (HKA angle on long leg films). The difficulty of obtaining correct alignment in knee arthroplasty, is that as surgeons we need to find and use anatomical axes and landmarks, in the arthritic and often deformed knee, to align the implant well mechanically. Conventional instruments do the job well for 2/3 of patients, but for 1/3 we need some additional help. Navigation and patient-specific instruments (PSI) should make us more accurate surgeons.
Finding the anatomical landmarks used for correct femoral rotational alignment can be difficult. The Posterior Condylar Line (PCL) is probably the easiest to find during surgery. The aim of this study was to analyze if a predetermined fixed angle referencing of the PCL could help obtain good femoral alignment in TKA patients. 2637 CT scans used for preoperative planning and creation of patient-specific instrumentation (PSI) were used to analyze the Posterior Condylar Angle (PCA) between the Surgical Epicondylar Axis (SEA) and the PCL.Background
Methods
The importance of frontal and rotational alignment in total knee arthroplasty has been published. Together with conventional instrumentation, computer navigation has been used for many years now. The pro's and con's of navigation are well known since. We present the results of our first 200 total knee arthroplasties with a Patient Specific Instrument System, called Signature (Biomet). With this system an MRI of the hip, knee and ankle is performed. Based on these images, mechanical axis and rotational landmarks are decided. Preoperative planning and templating is done with a computer program. Alignment, rotation, slope, size, positioning and gaps are planned with the software. Based on this templating a femoral guide and a tibial guide are custom made (Materialise) for each patient that will allow only one unique fit and position. Both of these guides are no cutting guides but pinning guides. From that stage on Vanguard Total Knee (Biomet) is implanted with this system applying conventional surgical techniques and rules. Preoperative alignment was measured on standing full leg X-rays. Rotational alignment was set according to the epicondylar axis. Slope was by default fixed at 3° posterior slope. Femoral flexion was set at 3° by default. Sizing was done with the system. Tourniquet time, blood loss, mean Hb drop and lateral release rate as hospital stay were analyzed. Postoperative full leg X-rays and CT scan were analyzed.Introduction
Materials & Methods
Total Knee Arthroplasty (TKA) has a tendency to change the individual anatomy of the patient within the limits of today used arthroplasty designs. Femoral external rotation will lead to mediolateral overhang by upsizing to avoid lateral notching and downsizing will lead to loss of posterior condylar offset. Posterior slope is usually reduced to avoid problems with posterior stabilized (PS) designs. We compared 50 bicompartimental arthroplasties (Uni + PFJ) with 50 TKA's. Demographics and BMI are compared. We looked specifically at patient type, preoperative deformity, postoperative function and alignment and results on functional scores. Bicompartimental arthroplasty is a resurfacing intervention that allows less correction of frontal deformity. Postop alignment was within 3° of varus. Better active flexion was obtained than in TKA. Better function was observed for stair climbing and single leg stability. Rotational position of foot was more natural in bicompartimental as compared to TKA. Functional scores like WOMAC, KOOS and IKDC showed better results for bicompartimental. Illness perception score showed that the resurfacing patient is another patient than the TKA patient. No overhang of components was observed. No change of posterior condylar offset was necessary. Posterior slope on the medial side was minimally reduced. In conclusion resurfacing by bicompartimental arthroplasty with two individual components (Uni + PFJ) is an excellent solution to gender and ethnic differences. The individual anatomy of the specific patient goes through minimal changes resulting in better functional results.
The following data were assembled by a skin incision blinded study nurse: VAS, use of morphine pump, range of motion, straight leg raising, time to independent ambulation, time to discharge, wound problems and complications up to 6 weeks postoperative.
