THE PATELLOFEMORAL JOINT: Kinematic and Biomechanical Behaviour and its Clinical Application to Knee Arthroplasty

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Indications for primary rotating-hinge total knee arthroplasty. Is there consensus?

The use of rotating-hinge systems in total knee arthroplasty is most often seen in revision setting where excessive bone loss, ligamentous instability and/ or extensor mechanism dysfunction may necessitate an increased level of component constraint. However, this implant type is also being increasingly used in the primary setting. The aim of this study is to review literature concerning the use of third generation rotating-hinge devices focusing on the indications for primary cases. Literature was searched for following search terms: total knee arthroplasty, primary indication, constraint, rotating hinge knee, knee prosthesis, hinged knee, total knee replacement. Additional papers were identified by screening references and similar articles. All papers dealing with first or second generation rotating-hinge implants and revision cases were discarded. After conducting a large literature search, we concluded that third generation rotating-hinge implants should be considered in limited indications in which ligamentous tibiofemoral instability is the core indication.status: publishe

Proximalisation of the tibial tubercle gives a good outcome in patients undergoing revision total knee arthroplasty who have pseudo patella baja

AIMS: The aim of this study was to compare the outcome of revision total knee arthroplasty (TKA) with and without proximalisation of the tibial tubercle in patients with a failed primary TKA who have pseudo patella baja. PATIENTS AND METHODS: All revision TKAs, performed between January 2008 and November 2013 at a tertiary referral University Orthopaedic Department were retrospectively reviewed. Pseudo patella baja was defined using the modified Insall-Salvati and the Blackburne-Peel ratios. A proximalisation of the tibial tubercle was performed in 13 patients with pseudo patella baja who were matched with a control group of 13 patients for gender, age, height, weight, body mass index, length of surgery and Blackburne-Peel ratio. Outcome was assessed two years post-operatively using the Knee Society Score (KSS). RESULTS: The increase in KSS was significantly higher in the osteotomy group compared with the control group. The outcome was statistically better in patients in whom proximalisation of > 1 cm had been achieved compared with those in whom the proximalisation was < 1 cm. CONCLUSION: In this retrospective case-control study, a proximal transfer of the tibial tubercle at revision TKA in patients with pseudo patella baja gives good outcomes without major complications.status: publishe

the influence of weather conditions on osteoarthritis and joint pain after prosthetic surgery

The purpose of this narrative review was to highlight the research on the influence of weather conditions on patients with osteoarthritis, the pathophysiological mechanisms and the therapeutic consequences. A search was conducted using the Pubmed, Medline and Web of Science databases. Barometric pressure, temperature and humidity are the weather conditions that are found to be correlated most to the worsening of pain complaints. But, due to the difficulty of measuring the impact of these variables and the great diversity in study protocols, an analysis of studies regarding this topic shows conflicting results. Central sensitization mechanisms and the function of a Transient Receptor Potential channel might explain the pain hypersensitivity to cold weather. Joint pain, caused by central sensitization mechanisms, cannot always be treated with joint arthroplasty. When pain remains present after joint arthroplasty, centrally mediated pain constitutes an important role

The influence of weather conditions on osteoarthritis and joint pain after prosthetic surgery

The purpose of this narrative review was to highlight the research on the influence of weather conditions on patients with osteoarthritis, the pathophysiological mechanisms and the therapeutic consequences. A search was conducted using the Pubmed, Medline and Web of Science databases. Barometric pressure, temperature and humidity are the weather conditions that are found to be correlated most to the worsening of pain complaints. But, due to the difficulty of measuring the impact of these variables and the great diversity in study protocols, an analysis of studies regarding this topic shows conflicting results. Central sensitization mechanisms and the function of a Transient Receptor Potential channel might explain the pain hypersensitivity to cold weather. Joint pain, caused by central sensitization mechanisms, cannot always be treated with joint arthroplasty. When pain remains present after joint arthroplasty, centrally mediated pain constitutes an important role.status: publishe

Indications for primary rotating-hinge total knee arthroplasty. Is there consensus?

The use of rotating-hinge systems in total knee arthroplasty is most often seen in revision setting where excessive bone loss, ligamentous instability and/or extensor mechanism dysfunction may necessitate an increased level of component constraint. However, this implant type is also being increasingly used in the primary setting. The aim of this study is to review literature concerning the use of third generation rotating-hinge devices focusing on the indications for primary cases.Literature was searched for following search terms: total knee arthroplasty, primary indication, constraint, rotating hinge knee, knee prosthesis, hinged knee, total knee replacement. Additional papers were identified by screening references and similar articles. All papers dealing with first or second generation rotating-hinge implants and revision cases were discarded.After conducting a large literature search, we concluded that third generation rotating-hinge implants should be considered in limited indications in which ligamentous tibiofemoral instability is the core indication

Mucoid degeneration of the anterior cruciate ligament; complete resection as equivalent treatment to partial resection.

Purpose: Mucoid degeneration (MD) of the anterior cruciate ligament (ACL) is a benign knee pathology, which is often indicated for surgical treatment if symptomatic. Most authors believe that partial ACL resection is the treatment of choice in symptomatic MD of the ACL. This study concerns complete ACL resection as a treatment of mucoid degenerated ACL. Methods: Thirteen patients were treated with complete ACL resection for symptomatic MD of the ACL from 2006 - 2016. Symptoms included limited range of motion (ROM) and posterior knee pain.Results: Preoperative and postoperative results of eleven patient were compared. Postoperative recovery was four weeks on average.  All patients (100%, n=11) reported an improvement in pain. All patients with a preoperative limited ROM (100%, n=9) reported a return to a normal (subjective) ROM. Eight patients (72.7%, n=8) reported an improvement of knee instability, while three patients (27.3%, n=3) experienced an unchanged knee stability. All patients (100%, n=11) reported a good to very good surgery satisfaction. Preoperative and postoperative KOOS questionnaires were compared and showed improvement in all categories. Conclusions: Complete resection of the ACL without ACL reconstruction is a reliable treatment for symptomatic cases of mucoid degenerated ACL

Good long-term survival and patient-reported outcomes after high tibial osteotomy for medial compartment osteoarthritis

The lateral closing and medial opening wedge high tibial osteotomy can correct a varus malalignment of the knee caused by medial compartment osteoarthritis. These procedures have produced great short-term and mid-term results. As no systematic review has examined their long-term results yet, the goal of this article was to compare the results of all articles about lateral closing and medial opening wedge high tibial osteotomies, published after the year 2000, with a mean follow-up of more than 10 years. A systematic search of the Medline, Web of Science and Cochrane databases resulted in the inclusion of 30 articles. All these studies combined examined the results of 7087 high tibial osteotomies in a total of 6636 patients after a mean follow-up of more than 10 years. Primary outcome measures were the survival rate of the osteotomy, functional scores, patient satisfaction and pain scores. Secondary outcome measures were alignment correction and the identification of factors influencing the survival of the osteotomy. The 5-year, 10-year, 15-year and 20-year survival rates, respectively, ranged from 86 to 100%, 64-97.6%, 44-93.2% and 46-85.1%. The subjective scoring systems showed an improvement postoperatively that was maintained until final follow-up. The anatomical and mechanical tibiofemoral axis were, respectively, corrected to a mean of 7.3°-13.8° of valgus and 0.6°-4° of valgus. The results of the articles evaluating the influence of potential risk factors were contradictory. Despite the low quality of the available evidence, the lateral closing and medial opening wedge high tibial osteotomy seem to remain valid long-term treatment options for patients with painful varus malalignment caused by isolated medial compartment osteoarthritis of the knee. The available results indicate that the need for arthroplasty could be delayed for more than 15 years in the majority of patients. However, higher-quality studies are needed to confirm these findings. As a systematic review is assigned a level of evidence equivalent to the lowest level of evidence used from the analyzed manuscripts, the level of evidence of this systematic review is IV.status: publishe

The influence of coronal plane deformity on mediolateral ligament status: an observational study in varus knees

Most surgeons believe that varus deformity leads to progressive tightness of the medial soft tissue envelope and laxity on the lateral side. It is, however, unclear at what stage of the deformity such ligament alterations occur, and whether these are the consequence of intrinsic alterations in the ligaments themselves, or rather due to extrinsic factors such as osteophytes, adhesions to the underlying bone, or other factors which may cause a tightening effect. Thirty-five varus knees that were scheduled for TKA were investigated. Ligament status was evaluated after temporary correction of alignment and removal of osteophytes, using varus/valgus testing with computer navigation technology. Knees with < 10A degrees varus deformity were easily correctable to neutral after correction of the extrinsic factors that could cause medial tightness, and these knees maintained normal mediolateral laxity during varus/valgus stress testing. When coronal plane deformity exceeded 10A degrees, progressive shortening of the medial collateral ligament was noted, as well as progressive stretching of the lateral structures (P < 0.001). This study, therefore, demonstrates that the medial collateral structures become intrinsically shortened when preoperative varus deformity exceeds 10A degrees. Likewise, the lateral soft tissues become stretched. None of these occur when the preoperative deformity is < 10A degrees

The Chitranjan Ranawat award: is neutral mechanical alignment normal for all patients?: the concept of constitutional varus

Background Most knee surgeons have believed during TKA neutral mechanical alignment should be restored. A number of patients may exist, however, for whom neutral mechanical alignment is abnormal. Patients with so-called "constitutional varus" knees have had varus alignment since they reached skeletal maturity. Restoring neutral alignment in these cases may in fact be abnormal and undesirable and would likely require some degree of medial soft tissue release to achieve neutral alignment. Questions/purposes We investigated what percentage of the normal population has constitutional varus knees and what are the contributing factors. Subjects and Methods We recruited a cohort of 250 asymptomatic adult volunteers between 20 and 27 years old for this cross-sectional study. All volunteers had full-leg standing digital radiographs on which 19 alignment parameters were analyzed. The incidence of constitutional varus alignment was determined and contributing factors were analyzed using multivariate prediction models. Results Thirty-two percent of men and 17% of women had constitutional varus knees with a natural mechanical alignment of 3A degrees varus or more. Constitutional varus was associated with increased sports activity during growth, increased femoral varus bowing, an increased varus femoral neck-shaft angle, and an increased femoral anatomic mechanical angle. Conclusions An important fraction of the normal population has a natural alignment at the end of growth of 3A degrees varus or more. This might be a consequence of Hueter-Volkmann's law. Restoration of mechanical alignment to neutral in these cases may not be desirable and would be unnatural for them