The Stiff Knee

Klinische Diagnostik, Differenzialdiagnostik, Pathogenese- und Stadienmodell der Arthrofibrose

Die Arthrofibrose (AF) gehört zu den häufigsten Komplikationen nach Verletzungen und operativen Eingriffen an Gelenken, v. a. nach Gelenk- und Kreuzbandersatz. Alle großen Gelenke können betroffen sein, am häufigsten ist es jedoch das Kniegelenk. Es kommt zur schmerzhaften Bewegungseinschränkung durch Vermehrung von fibrotischem Gewebe innerhalb und teilweise auch außerhalb des Gelenks. Der normale Heilungsprozess ist durch mechanische und emotionale Stressoren sowie starke Schmerzreize gestört. Die AF tritt zu 90 % schon wenige Tage nach der Verletzung oder Operation auf, sodass die Qualitätsstandards nicht erreicht werden können. Durch Physiotherapie und Rehabilitation kann oft keine wesentliche Verbesserung der Funktion erreicht werden, sodass die Aktivitäten des täglichen Lebens (ADL) stark eingeschränkt sind. Klinische Diagnostik, Differenzialdiagnostik sowie ein neues Pathogenese- und Stadienmodell der primären AF mit den daraus abgeleiteten therapeutischen Prinzipien werden vorgestellt.

Differences in synovial fibrosis relative to range of motion in knee osteoarthritis patients

This study tests if differences exist in the severity of synovial fibrosis between patients undergoing total knee arthroplasty (TKA) for osteoarthritis (OA) to help explain disparate deficits in pre- and postoperative range of motion (ROM) between patient groups. 117 knee OA patients were grouped by women (n = 74) and men (n = 43) or those who self-reported as Black (n = 48) or White (n = 69). ROM was measured pre- and post-TKA. Condyles and synovium collected during TKA were scored histologically for OA severity and synovitis. Fibrosis was measured from picrosirius-stained sections of the synovium. Data were analyzed using Mann-Whitney, parametric, and Spearman's rho tests with alpha at 0.05. We found no significant differences between patient age, BMI, radiographic scores, or deformity type when grouped by sex or race, or between metrics or OA severity when grouped by sex. Notably, higher synovitis was measured in women (p = .039) than men. White patients had greater ROM before (p = 0.46) and after surgery (p = .021) relative to Black patients. Fibrosis, but not OA severity and synovitis scores, for the total patient sample negatively correlated with preoperative (r _s  = -0.330; p = .0003) but not postoperative (r_s  = -0.032; p = .7627) ROM. Black patients manifested more fibrosis than White patients (p = <.0001), without significant differences between sexes. Statement of Clinical Significance: Coupled with histological scoring, measuring perioperative differences in synovial fibrosis against ROM may refine OA classification and justify the in-depth preoperative assessment of the knee as a whole. Such individualized analyses could guide personalized strategies to relieve symptomatic OA when TKA is not readily accessible and promote equitable TKA outcomes.

Benefits and Mechanisms of Exercise Training for Knee Osteoarthritis

Knee osteoarthritis is a chronic degenerative disease. Cartilage and subchondral bone degeneration, as well as synovitis, are the main pathological changes associated with knee osteoarthritis. Mechanical overload, inflammation, metabolic factors, hormonal changes, and aging play a vital role in aggravating the progression of knee osteoarthritis. The main treatments for knee osteoarthritis include pharmacotherapy, physiotherapy, and surgery. However, pharmacotherapy has many side effects, and surgery is only suitable for patients with end-stage knee osteoarthritis. Exercise training, as a complementary and adjunctive physiotherapy, can prevent cartilage degeneration, inhibit inflammation, and prevent loss of the subchondral bone and metaphyseal bone trabeculae. Increasing evidence indicates that exercise training can improve pain, stiffness, joint dysfunction, and muscle weakness in patients with knee osteoarthritis. There are several exercise trainings options for the treatment of knee osteoarthritis, including aerobic exercise, strength training, neuromuscular exercise, balance training, proprioception training, aquatic exercise, and traditional exercise. For Knee osteoarthritis (KOA) experimental animals, those exercise trainings can reduce inflammation, delay cartilage and bone degeneration, change tendon, and muscle structure. In this review, we summarize the main symptoms of knee osteoarthritis, the mechanisms of exercise training, and the therapeutic effects of different exercise training methods on patients with knee osteoarthritis. We hope this review will allow patients in different situations to receive appropriate exercise therapy for knee osteoarthritis, and provide a reference for further research and clinical application of exercise training for knee osteoarthritis.

Effects of Each Phase of Anterior Cruciate Ligament Reconstruction Surgery on Joint Contracture in Rats

BACKGROUND

Although anterior cruciate ligament reconstruction surgery is known to cause joint contracture, the mechanisms of this process are unknown. We aimed to assess the effects of transection of this ligament and each phase of reconstruction surgery on contracture formation.

MATERIALS AND METHODS

Rats were divided into groups according to treatment received: sham (arthrotomy), ligament transection, ligament transection plus bone drilling, and ligament reconstruction. Surgery was performed on the right knee. Untreated left knees in the sham group were used as controls.

RESULTS

At 7 and 28 d post-surgery, range of motion before myotomy, mainly representing myogenic contracture, was restricted in the sham and ligament transection groups, and more so in the bone drilling and reconstruction groups. Restricted range of motion after myotomy, representing arthrogenic contracture, was detected at both timepoints in the bone drilling and reconstruction groups, but not in the sham or ligament transection groups. At 3 d post-surgery, although a large blood clot was observed in all three treatment groups, only the bone drilling and reconstruction groups showed significant joint swelling. At 7 d post-surgery, inflammatory-cell infiltration into the joint capsule was most apparent in the bone drilling and reconstruction groups, and joint capsule fibrosis was also most apparent in these groups at 7 and 28 d post-surgery.

CONCLUSIONS

Our results suggest that (1) myogenic contracture after anterior cruciate ligament reconstruction is caused by arthrotomy and aggravated by bone drilling, and (2) arthrogenic contracture is mostly due to bone drilling, which triggers an inflammation-fibrosis cascade.

Medical stretching devices are effective in the treatment of knee arthrofibrosis: A systematic review

AIMS

This systematic review examines the available evidence on the use of medical stretching devices to treat knee arthrofibrosis, it suggests a focus for future studies addressing limitations in current research and identifies gaps in the published literature to facilitate future works.

MATERIALS AND METHODS

Articles were identified using the Cochrane Library, MEDLINE, PubMed and SCOPUS databases. Articles from peer reviewed journals investigating the effectiveness of medical stretching devices to increase range of movement when treating arthrofibrosis of the knee were included.

RESULTS

A total of 13 studies (558 participants) met the inclusion criteria with the devices falling into the following categories; CPM, load control or displacement control stretching devices. A statistically significant increase in range of movement was demonstrated in CPM, load-control and displacement-control studies (p ​< ​0.001). The results show that the stretch doses applied using the CPM, load-control devices were performed over a considerably longer treatment time and involved significantly more additional physiotherapy compared to the displacement-control and patient actuated serial stretching devices.

CONCLUSION

The systematic review indicates that load-control and displacement-control devices are effective in increasing range of movement in the treatment of knee arthrofibrosis. Displacement-control devices involving patient actuated serial stretching techniques, may be more effective in increasing knee flexion than those utilising static progressive stretch.The paucity of research in this field indicates that more randomised controlled trials are required to investigate the superiority of the different types of displacement-control stretching devices and which of these would be most effective for use in clinical practice and to compare these with standard physiotherapy treatment.

Literature review of the causes of pain following total knee replacement surgery: prosthesis, inflammation and arthrofibrosis

Adverse knee pain occurs in 10–34% of all total knee replacements (TKR), and 20% of TKR patients experience more pain post-operatively than pre-operatively. Knee pain is amongst the top five reasons for knee replacement revision in the United Kingdom. The number of TKRs is predicted to continue increasing due to the ageing population.

A narrative literature review was performed on the different causes of pain following TKR. A database search on Scopus, PubMed, and Google Scholar was conducted to look for articles related to TKR, pain, and cause. Articles were selected based on relevance, publication date, quality of research and validation. Relevant sections were added to the review.

One hundred and fourteen articles were identified and potential causes of TKR pain included: arthrofibrosis, aseptic loosening, avascular necrosis, central sensitization, component malpositioning, infection, instability, nerve damage, overstuffing, patellar maltracking, polyethylene wear, psychological factors and unresurfaced patella.

It is important to tailor our approach to address the individual causes of pain. Certain controllable risk factors can be managed pre-operatively to minimize post-operative pain. Risk factors help to predict adverse pain outcomes and identify specific causes.

There are multiple causes of pain following TKR. Some factors will require further extensive studies, and as pain is a commonly attributed reason for TKR revision, its underlying aetiologies should be explored. Understanding these factors helps to develop effective methods for diagnosis, prevention and management of TKR pain, which help to improve patient outcomes.

Cite this article: EFORT Open Rev 2020;5:534-543. DOI: 10.1302/2058-5241.5.200031