The clinical outcome of total knee arthroplasty is compromised by a previously implanted medial unicondylar knee arthroplasty

OBJECTIVE

To investigate the clinical outcome of patients that underwent conversion of a medial unicondylar knee arthroplasty (UKA) to a total knee arthroplasty (TKA) and to compare that outcome to patients that underwent primary TKA. It was hypothesized that those groups would significantly differ in terms of knee score outcome and implant survival.

METHODS

A retrospective-comparative study was conducted utilizing data from the Federal state's arthroplasty registry. Included were patients from our department that undergone a conversion of a medial UKA to a TKA (UKA-TKA group). The Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC) from preoperative and 1-year postoperative was used. Moreover, the implant survival was analyzed.

RESULTS

In the UKA-TKA group, there were 51 cases (age 67 ± 10, 74% women), and in the TKA group, there were 2247 cases (age 69 ± 9, 66% women). The one-year postoperative WOMAC total score was 33 in the UKA-TKA group und 21 in the TKA group (p < 0.001). Similarly, the WOMAC pain, WOMAC stiffness, and WOMAC function scores were significantly worse in the UKA-TKA. After 5 years, the survival rates were 82% and 95% (p = 0.001). The 10-years prosthesis survival was 74% and 91% in the UKA-TKA and TKA groups, respectively (p < 0.001).

CONCLUSIONS

Based on our findings it is concluded that patients who received a TKA after UKA have inferior results than those that directly receive a TKA. This is true for both patient-reported knee outcome and prosthesis survival. Converting UKA to TKA should not be seen as an easy operation, but should rather be done by surgeons with considerable experience in both primary and revision knee arthroplasty.

[A multidimensional v-shaped distalizing osteotomy of the tibial tuberosity with a proximal buttress ("coffin-shaped" osteotomy)]

The aim of the intervention presented is a distalization of the tibial tuberosity. It is indicated in patients with symptomatic patella alta, i.e. patients with instability of the patella. It facilitates a V-shaped osteotomy. The bone gained during distalization is used as a proximal buttress. This leads to an improved mediolateral and proximal stability. The bony surface area is increased, which improves bony healing. There were no secondary dislocations in the patient group of 10 patients treated by the surgeon.

Resuming elective hip and knee arthroplasty after the first phase of the SARS-CoV-2 pandemic: the European Hip Society and European Knee Associates recommendations

PURPOSE

The Covid-19 pandemic has disrupted health care systems all over the world. Elective surgical procedures have been postponed and/or cancelled. Consensus is, therefore, required related to the factors that need to be in place before elective surgery, including hip and knee replacement surgery, which is restarted. Entirely new pathways and protocols need to be worked out.

METHODS

A panel of experts from the European Hip Society and European Knee Association have agreed to a consensus statement on how to reintroduce elective arthroplasty surgery safely. The recommendations are based on the best available evidence and have been validated in a separate survey.

RESULTS

The guidelines are based on five themes: modification and/or reorganisation of hospital wards. Restrictions on orthopaedic wards and in operation suite(s). Additional disinfection of the environment. The role of ultra-clean operation theatres. Personal protective equipment enhancement.

CONCLUSION

Apart from the following national and local guidance, protocols need to be put in place in the patient pathway for primary arthroplasty to allow for a safe return.

It is not 'business as usual' for orthopaedic surgeons in May 2020- the Austrian-German-Swiss experience

PURPOSE

To document the status-quo of orthopaedic health-care services as the COVID-19 pandemic recedes, and to determine the rate of resumption of orthopaedic surgery in the German-speaking countries in May 2020.

METHODS

A prospective online survey was sent out to 4234 surgeons of the AGA - Society of Arthroscopy and Joint-Surgery (Gesellschaft für Arthroskopie und Gelenkchirurgie, AGA). The survey was created using SurveyMonkey software and consisted of 23 questions relating to the reduction of orthopaedic services at the participating centres and the impact that the pandemic is having on each surgeon.

RESULTS

A total of 890 orthopaedic surgeons responded to the online survey. Approximately 90% of them experienced a reduction in their surgical caseload and patient contact. 38.7% stated that their institutions returned to providing diagnostic arthroscopies. 54.5% reported that they went back to performing anterior cruciate ligament reconstructions (ACLR), 62.6% were performing arthroscopic meniscus procedures, and 55.8% had resumed performing shoulder arthroscopy. Only 31.9% of the surgeons were able to perform elective total joint arthroplasty. 60% of the participants stated that they had suffered substantial financial loss due to the pandemic.

CONCLUSION

A gradual resumption of orthopaedic health-care services was observed in May 2020. Typical orthopaedic surgical procedures like ACLR, shoulder arthroscopy and elective total joint arthroplasty were reported to be currently performed by 54%, 56% and 32% of surgeons, respectively. Despite signs of improvement, it appears that there is a prolonged curtailment of orthopaedic health-care at present in the middle of Europe.

Disruption of joint arthroplasty services in Europe during the COVID-19 pandemic: an online survey within the European Hip Society (EHS) and the European Knee Associates (EKA)

PURPOSE

The aim of the present study was to evaluate the impact of the coronavirus (COVID-19) pandemic on joint arthroplasty service in Europe by conducting an online survey of arthroplasty surgeons.

METHODS

The survey was conducted in the European Hip Society (EHS) and the European Knee Associates (EKA). The survey consisted of 20 questions (single, multiple choice, ranked). Four topics were addressed: (1) origin and surgical experience of the participant (four questions); (2) potential disruption of arthroplasty surgeries (12 questions); (3) influence of the COVID-19 pandemic on the particular arthroplasty surgeon (four questions); (4) a matrix provided 14 different arthroplasty surgeries and the participant was asked to state whether dedicated surgery was stopped, delayed or cancelled.

RESULTS

Two-hundred and seventy-two surgeons (217 EHS, 55 EKA) from 40 different countries participated. Of the respondents, 25.7% stated that all surgeries were cancelled in their departments, while 68.4% responded that elective inpatient procedures were no longer being performed. With regard to the specific surgical procedures, nearly all primary TJA were cancelled (92.6%) as well as aseptic revisions (94.7%). In most hospitals, periprosthetic fractures (87.2%), hip arthroplasty for femoral neck fractures and septic revisions for acute infections (75.8%) were still being performed.

CONCLUSION

During the current 2020 COVID-19 pandemic, we are experiencing a near-total shutdown of TJA. A massive cutback was observed for primary TJA and revision TJA, even in massively failed TJA with collapse, dislocation, component failure or imminent dislocation. Only life-threatening pathologies like periprosthetic fractures and acute septic TJA are currently undergoing surgical treatment.

LEVEL OF EVIDENCE

V.

Recommendations for resuming elective hip and knee arthroplasty in the setting of the SARS-CoV-2 pandemic: the European Hip Society and European Knee Associates Survey of Members

PURPOSE

The COVID-19 pandemic has disrupted the health care system around the entire globe. A consensus is needed about resuming total hip and knee procedures. The European Hip Society (EHS) and the European Knee Association (EKA) formed a panel of experts that have produced a consensus statement on how the safe re-introduction of elective hip and knee arthroplasty should be undertaken.

METHODS

A prospective online survey was done among members of EHS and EKA. The survey consisted of 27 questions. It includes basic information on demographics and details the participant's agreement with each recommendation. The participant could choose among three options (agree, disagree, abstain). Recommendations focussed on pre-operative, peri-operative, and post-operative handling of patients and precautions.

RESULTS

A total of 681 arthroplasty surgeons participated in the survey, with 479 fully completing the survey. The participants were from 44 countries and 6 continents. Apart from adhering to National and Local Guidelines, the recommendations concerned how to make elective arthroplasty safe for patients and staff.

CONCLUSION

The survey has shown good-to-excellent agreement of the participants with regards to the statements made in the recommendations for the safe return to elective arthroplasty following the first wave of the COVID-19 pandemic.

The anterolateral ligament and the deep structures of the iliotibial tract: MRI visibility in the paediatric patient

PURPOSE

To assess the visibility of both the anterolateral ligament (ALL) and the deep structures of the iliotibial tract (ITT) by means of MRI in paediatric patients. To determine reproducibility for such measurements.

METHODS

Knee MRI data from patients aged <18a without lesions of the capsule or ligaments, fractures, bone edemas, foreign material or motion artifacts were analyzed by two musculoskeletal radiologists separately and twice. The visibility of the different parts of the ALL was determined (femoral, meniscal, tibial parts). Similarly, the visibility of the different parts of the deep ITT was determined: deep attachments of the ITT to the distal femur (insertion near septum, supracondylar insertion and retrograde insertion) and capsulo-osseous layer of the ITT.

RESULTS

We studied 61 cases (36 female, 25 male). Age was 15 years (±2.3). Interobserver agreement was high. Cohen's Kappa was 0.864 (95%CI: 0.715-1.000) for the tibial part of the ALL and 1.0 for the femoral part of the ALL. For the deep attachments of the ITT to the distal femur Kappa was 0.828 (95%CI: 0.685-0.971). Regarding intraobserver agreement, Cohen's Kappa was 1.0 for the femoral part of the ALL and 0.955 (95%CI: 0.867-1.000) for the tibial part of the ALL. For the deep attachments of the ITT to the distal femur Cohen's Kappa was 0.896 (95%CI: 0.782-1.000).

CONCLUSION

On the basis of our findings it is concluded that the presence of the anterolateral structures of the knee can be determined by MRI in a pediatric population with substantial inter- and intraobserver agreement. This is true for both the ALL and the deep structures of the ITT.

LEVEL OF EVIDENCE

Diagnostic study - Level 3.

What makes patients aware of their artificial knee joint?

Background

Joint awareness was recently introduced as a new concept for outcome assessment after total knee arthroplasty (TKA). Findings from qualitative and psychometric studies suggest that joint awareness is a distinct concept especially relevant to patients with good surgical outcome and patients at late follow-up time points. The aim of this study was to improve the understanding of the concept of joint awareness by identifying situations in which patients are aware of their artificial knee joint and to investigate what bodily sensations and psychological factors raise a patient’s awareness of her/his knee. In addition, we evaluated the relative importance of patient-reported outcome parameters that are commonly assessed in orthopaedics.

Methods

Qualitative interviews were conducted with patients being at least 12 months after TKA. The interviews focused on when, where and for what reasons patients were aware of their artificial knee joint. To evaluate the relative importance of ‘joint awareness’ after TKA among nine commonly assessed outcome parameters (e.g. pain or stiffness), we collected importance ratings (‘0’ indicating no importance at all and ‘10’ indicating high importance).

Results

We conducted interviews with 40 TKA patients (mean age 69.0 years; 65.0% female). Joint awareness was found to be frequently triggered by kneeling on the floor (30%), climbing stairs (25%), and starting up after resting (25%). Patients reported joint awareness to be related to activities of daily living (68%), specific movements (60%), or meteoropathy (18%). Sensations causing joint awareness included pain (45%) or stiffness (15%). Psychological factors raising a patient’s awareness of his/her knee comprised for example feelings of insecurity (15%), and fears related to revision surgeries, inflammations or recurring pain (8%). Patients’ importance ratings of outcome parameters were generally high and did not allow differentiating clearly among them.

Conclusions

We have identified a wide range of situations, activities, movements and psychological factors contributing to patients’ awareness of their artificial knee joints. This improves the understanding of the concept of joint awareness and of a patient’s perception of his/her artificial knee joint. The diversity of sensations and factors raising patient’s awareness of their joint encourages taking a broader perspective on outcome after TKA.

[Arthroscopic procedure for Baker's cysts : surgical technique. Video article]

BACKGROUND

Baker's cysts are related to increased intra-articular pressure. The causes may be inflammatory, degenerative or traumatic disorders. Owing to the increased intra-articular pressure a cyst protrudes between the semimembranosus and the medial gastrocnemius tendons. The traditional treatment for a Baker's cyst is open resection. As an alternative, an arthroscopic procedure can be performed, which is demonstrated by the video on surgical technique that accompanies this short report.

SURGICAL TECHNIQUE

From the anterolateral portal the arthroscope is advanced through the intercondylar notch (below the posterior cruciate ligament) to the posteromedial recess. Under visual control, a posteromedial portal is created followed by identification of the capsular fold separating the cyst from the joint cavity. This fold (valvular mechanism) is resected with a shaver from the posteromedial portal until a large enough connection exists between the joint and the cyst (cyst decompression). After the decompression, the arthroscope is inserted from the posteromedial portal directly into the cyst cavity. Subsequently, the inner wall of the cyst is removed with the shaver via an additional far posterior cystic portal. It is obligatory to treat the associated intra-articular pathological condition. In our video a medial meniscal lesion is treated with partial meniscectomy.

Brake response time returns to the pre-surgical level 6 weeks after unicompartmental knee arthroplasty

PURPOSE

The objective of the study was to clarify whether driving abstinence should be recommended when patients are discharged from hospital after unicompartmental knee arthroplasty (UKA). We tested the hypotheses that there are differences in the peri-operative course of brake response time in patients undergoing right-sided (1) or left-sided (2) UKA. Additionally, we tested whether brake response time is significantly influenced by pain (3), driving experience (4) or age (5).

METHODS

In 43 patients undergoing UKA, brake response time was measured with a custom-made driving simulator pre-operatively and 1 and 6 weeks after UKA. Patients' visual analogue scales for knee pain and their self-reported driving experience were also assessed.

RESULTS

In patients with right-sided UKA, brake response time changed from 786 (261) ms pre-operatively to 900 (430) ms 1 week post-operatively (p = 0.029). At 6 weeks post-operatively, brake response time had returned to 712 (139) ms, which was deemed to be an insignificant change from the pre-operative reference benchmark. When surgery was performed on the contralateral left side, no effect was found onto the right side's brake response time. Knee pain and driving experience were significantly correlated with brake response time. No such correlations were found between brake response time and age.

CONCLUSIONS

On the basis of the current findings, it is concluded that brake response time returns to pre-operative levels 6 weeks after UKA surgery. Therefore, it is proposed that driving be abstained from for that period.

Correlation between objective gait parameters and subjective score measurements before and after total knee arthroplasty

The absence of uniformity, the use of different terminologies, and the diversity of methods used to translate numerical data into clinical outcomes have been described as potential problems when dealing with clinical knee scores for total knee arthroplasty (TKA). Gait analysis is believed to provide more objective parameters. The aim of the present study was to obtain information about the correlation between the outcome in terms of locomotion and the clinical knee score after TKA. Thirty consecutive patients awaiting TKA were involved in the study. One day prior to surgery and 3 months postoperatively, data pertaining to the Hospital for Special Surgery Score (HSS) and the Knee Society Score (KSS) (subgroups 'pain', 'knee', 'function' and 'total sum') were analyzed for correlations with kinematic and temporospatial parameters of gait analysis. At a significance-level of p</=0.001 moderate correlations (0.4<r<0.6) were found preoperatively, particularly between 'max knee flexion swing' and the function-subscores of HSS and KSS and the 'KSS total'. High correlations (0.6<r<0.8) were ascertained for 'stride length' and 'gait velocity' with 'KSS function'. High correlations were also determined between 'stride length' and 'KSS total' and between 'gait velocity' and 'HSS function'. The only correlation found postoperatively was between 'max pelvic obliquity stance' and 'KSS knee' (r=0.770, p<0.001). We conclude that the 'function' subscores of KSS and HSS are highly suitable to assess the functional capacity of patients scheduled for TKA. However, because no adequate correlations between knee scores and gait parameter were found postoperatively, we cannot recommend the abandonment of gait analysis when monitoring the functional benefit of TKA.

Frontal plane leg alignment and muscular activity during maximum eccentric contractions in individuals with and without patellofemoral pain syndrome

PURPOSE

The role of frontal plane tibiofemoral alignment in subjects with patellofemoral pain syndrome (PFPS) is controversial and rarely discussed in the literature. As well, little research has been done on the effects of the hamstrings muscles on PFPS. The aim of the current study was to determine whether, in individuals with PFPS, frontal plane tibiofemoral alignment or muscular activity of the index knee's crossing muscles is altered during maximum eccentric leg press exercise.

METHODS

This cross-sectional study involved 19 patients with PFPS and 19 control subjects who were matched according to gender, age, and physical activity. During eccentric leg press action, frontal plane tibiofemoral alignment was assessed with a motion analysis system based on skin markers. Simultaneously, surface-electromyography was used to assess the activity levels of the relevant knee crossing muscles. To assess the activity under functional conditions, a leg press with a footplate having variable stability was used for barefoot testing.

RESULTS

The PFPS subjects did not have significantly different frontal plane leg alignment compared to controls. On electromyography (EMG), PFPS patients had significantly lower levels of hamstring activity during eccentric leg exercise. The differences between the two groups (%; absolute differences normalized EMG) ranged from 20% (semitendinosus; stable footplate; p=0.017) to 21% (biceps femoris; unstable footplate; p=0.019) and 32% (semitendinosus; unstable footplate; p=0.002).

CONCLUSIONS

PFPS is not linked to altered frontal plane leg alignment during eccentric leg pressing. However, PFPS is associated with eccentric under-activation of the hamstrings, which may be a compensatory strategy that maintains patellofemoral joint pressure within bearable levels.