Patients receiving reverse total shoulder arthroplasty (RTSA) often have osseous erosions because of glenohumeral arthritis, leading to increased surgical complexity. Glenoid implant fixation is a primary predictor of the success of RTSA and affects micromotion at the bone-implant interface. Augmented implants which incorporate specific geometry to address superior erosion are currently available, but the clinical outcomes of these implants are still considered short-term. The objective of this study was to investigate micromotion at the glenoid-baseplate interface for a standard, 3 mm and 6 mm lateralized baseplates, half-wedge, and full-wedge baseplates. It was hypothesized that the mechanism of load distribution from the baseplate to the glenoid will differ between implants, and these varying mechanisms will affect overall baseplate micromotion. Clinical CT scans of seven shoulders (mean age 69 years, 10°-19° glenoid inclinations) that were classified as having E2-type glenoid erosions were used to generate 3D scapula models using MIMICS image processing software (Materialise, Belgium) with a 0.75 mm mesh size. Each scapula was then repeatedly virtually reconstructed with the five implant types (standard,3mm,6mm lateralized, and half/full wedge; Fig.1) positioned in neutral version and inclination with full backside contact. The reconstructed scapulae were then imported into ABAQUS (SIMULIA, U.S.) finite element software and loads were applied simulating 15°,30°,45°,60°,75°, and 90° of abduction based on published instrumented in-vivo implant data. The micromotion normal and tangential to the bone surface, and effective load transfer area were recorded for each implant and abduction angle. A repeated measures ANOVA was used to perform statistical analysis. Maximum normal micromotion was found to be significantly less when using the standard baseplate (5±4 μm), as opposed to the full-wedge (16±7 μm, p=0.004), 3 mm lateralized (10±6 μm, p=0.017), and 6 mm lateralized (16±8 μm, p=0.007) baseplates (Fig.2). The half-wedge baseplate (11±7 μm) also produced significantly less micromotion than the full-wedge (p=0.003), and the 3 mm lateralized produced less micromotion than the full wedge (p=0.026) and 6 mm lateralized (p=0.003). Similarly, maximum tangential micromotion was found to be significantly less when using the standard baseplate (7±4 μm), as opposed to the half-wedge (12±5 μm, p=0.014), 3 mm lateralized (10±5 μm, p=0.003), and 6 mm lateralized (13±6 μm, p=0.003) baseplates (Fig.2). The full wedge (11±3 μm), half-wedge, and 3 mm lateralized baseplate also produced significantly less micromotion than the 6 mm lateralized (p=0.027, p=012, p=0.02, respectively). Both normal and tangential micromotion were highest at the 30° and 45° abduction angles (Fig.2). The effective load transfer area (ELTA) was lowest for the full wedge, followed by the half wedge, 6mm, 3mm, and standard baseplates (Fig.3) and increased with abduction angle. Glenoid baseplates with reduced lateralization and flat backside geometries resulted in the best outcomes with regards to normal and tangential micromotion. However, these types of implants are not always feasible due to the required amount of bone removal, and medialization of the bone-implant interface. Future work should study the acceptable levels of bone removal for patients with E-type glenoid erosion and the corresponding best implant selections for such cases. For any figures or tables, please contact the authors directly

Background: It is common sense that a hemiarthroplasty for the management of a fracture of neck of femur will inevitably lead to the erosion of the natural acetabulum. Therefore it appears appropriate to confine this treatment to patients with a short life expectancy to spare them the experience of this complication and consequent surgery, whereas younger and healthier patients would have to be offered a Total Hip Replacement for that reason. Occasional clinical experience of amazing longevity of hemiar-throplasties cast doubt on this way of thinking. Materials and Methods: A series of 699 hemiarthroplasties done in a Swiss orthopaedic department between 1983 to 2003, were studied with regard to revision surgery because of acetabular erosion. In addition to data from the MEM documentation system, acetabular biopsies retrieved on revision surgery were used for this analysis. The incidence of revision surgery for acetabular erosion was statistically compared with the incidence of primary Total Hip Replacement in the Norwegian Hip Register. Results: The incidence of acetabular erosion following hemiarthroplaty over 20 years in the Swiss series was determined for different age groups. In the most important age group of 70 to 79 years, in this series comprising 249 patients, this incidence was 3,2%. The incidence of Primary Total Hip Replacement for osteoarthritis in the Norwegian Hip Register over 20 years is 3,6% for the same age group. Conclusion: The incidence of acetabular erosion as a consequence of a hemiarthroplasty was surprisingly low in the Swiss series and did not exceed the incidence of Total Hip Replacement for primary osteoarthritis in a European national population. Acetabular erosion can’t be considered as an inevitable consequence of a hemiarthroplasty, but is to be seen as a complication confined to a certain group of patients

Abstract. Introduction. Bipolar hemiarthroplasty(BPHA) for displaced intracapsular neck of femur fractures(DICNOF) is a controversial topic as conflicting evidence exists. The most common reason for revision to total hip arthroplasty(THA) from BPHA is acetabular erosion. In our study, we sought to quantify the direction of migration of the bipolar head within the first 3 years post-operatively. Methods. A proportional index in the horizontal and vertical planes of the pelvis were used to quantify migration. This method removed the need to account for magnification and rotation of the radiographs. Results. There were a total of 35 patients (8males, 27females) included, with an average followup of 2.3years (816days). 7 did not migrate, these were all female. For the remainder, per year of insertion, the average horizontal migration was 0.005769439 and the average vertical migration was 0.004543352, suggesting superomedial movement. Discussion. BPHA has been shown to provide results similar to those of THA in patients with DICNOF. The main cause of revision to THA is migration thought to be from loss of cartilage volume from mechanical wear, that causes pain. We have quantified this migration as minimal. None of our patients required revision to THA and none sustained dislocation or loosening in this followup period. This would fit with the meta-analyses looking at BPHA, which shows bipolar articulations reduce the amount of wear. We also identified a trend that in the female population migration is less likely to occur. This would add evidence to the theory that mechanical factors are significant in the volumetric wear caused by hemiarthoplasty. Conclusion. BPHA was found to be safe and effective in our cohort of patients with minimal migration and no need for revision at an average of 2.3years. Our data is concurrent with the literature in theorising that BPHA reduces wear at the prosthesis-cartilage interface

We describe a technique to salvage a painful hemiarthroplasty due to erosion of the acetabular cartilage in the absence of loosening of the femoral component. A press-fit metallic acetabular component which matched the femoral component was used as a metal-on-metal articulation. The procedure offered a shorter operation time with less blood loss and no risk of femoral fracture as might have occurred during conventional revision to a total hip replacement. The patient made an unremarkable recovery with a good outcome at follow-up of 15 months

Aims. Unipolar and bipolar femur head replacement in the cases of proximal femur fractures is considered one of the most common surgical procedures. But the most often post-op complication is the acetabulum cartilage erosion. The aim of this research was to estimate the speed of cartilage erosion two mentioned above surgical operations. Methods. The follow-up of 75 patients after unipolar and 62 after bipolar in the period of 24–30 (average 25.6) months post-op was performed. The average age was 78 + 13,5 years. To increase the correctness of measurement we have used the method of computer-assistant evaluation of X-ray þlms, proposed by the author. X-ray þlms were scanned. After it the special virtual ruler was placed to the scanogram to measure needed data. The presence of the artiþcial joint in the pelvis area with known sizes of its components have given the opportunity to þt the virtual ruler according to the size of artiþcial joint (for example Ð prosthesis head diameter). Results. To get the cartilage wear speed we estimated þrst the height of the cartilage before the surgery. It was 4.55 mm in average and depended on the level of degenerative processes in the hip. The average follow-up period was 25.6 months. In this period both groups have shown the wear of the acetabular cartilage. The average cartilage erosion speed in the þrst (unipolar) group was higher (1.3 mm in 2 years) then in the second (bipolar) Ð 0.6 mm in 2 years. The erosion speed increased in the presence of preoperative signs of degenerative processes in the hip and depended on its level. Conclusions. Mentioned above data shows that bipolar hip replacement causes less destructive processes in the acetabulum than unipolar

Objective: to measure cartilage and bone acetabular erosion in patients treated with a bipolar hip hemiarthroplasty because of a femoral neck fracture. Material and methods:. - 34 patients, 31 female. average age 72.9 +/− 7.1 years (56–90). - Level of activity previous to fracture: 82.4% level III, 14.6% level II. - Displaced (Garden III and IV) fracture of femoral neck excluding pathologic fractures. - Hip hemiartrhoplasty with a JRI Furlong bipolar head (22.25 mm inner head), 30 patients with a Furlong HAP-coated uncemented stem and 4 patients with an auto-blocking-type Surgival cemented stem. - Follow-up: minimum 2 years, average 2.9 years (2–5). - Clinical evaluation: Merle-DAubigne-Postel six-point scale for pain and for function. - Radiological evaluation: measure of joint line width at superior-lateral quadrant (weight bearing area), perpendicular distance from prosthesis head to Kohler line. - Statistical analysis: Kolmogorov-Smirnov, ANOVA, Bonferroni, Pearson, and Spearman tests. Results – Pain: average score 4.5 +/− 1.3 after 1 year, 4.7 +/− 1.3 after 2 years, 4.6 +/− 1.4 after 3 years. - Function: average score 4.7 +/− 1.1 after 1 year, 4.7 +/− 1.4 after 2 years, 4.8 +/− 1.3 after 3 years. - Radiological joint line: disappeared in 13 patients (38.2%) after 1 year, in 14 (41.2%) after 2 years, in 54.5% of patients after 3 years. Average joint line width in the other patients: 0.9 mm (0.6–1.3) immediately after surgery, 0.6 mm (0.4–0.8) after 1 year, 0.5 mm (0.3–0.7) after 2 years, 0.5 mm (0.2–0.7) after 3 years (p< 0.05). - Distance from head to Kohler line: 5.7 +/− 3.8 mm (4.6–6.8) immediately after surgery, 4.6 +/− 3.7 mm (3.6–5.6) after 1 year, 4.3 +/− 2.9 mm (3.3–5.3) after 2 years, 4.0 +/− 3.3 mm (2.5–5.5) after 3 years (p< 0.05). There were 2 cases of acetabular protrusion. Conclusions 1. Bipolar heads in hemiarthroplasty do not avoid acetabular erosion. 2. The radiological progressive erosion does not correlate with clinical worsening of the patients

Nine cases of acetabular erosion following insertion of the Monk "hard top" hip prosthesis for subcapital fractures are presented. All of these patients had significant symptoms and represented 5% of the total group. In our experience acetabular erosion has proved to be a significant complication of the Monk "hard top" prosthesis

The best treatment for a fractured neck of femur in an old person is considered by many to be replacement hemiarthroplasty which allows the patient to walk immediately on a stable, painless hip. The late results can be marred by acetabular erosion in which the metal head of the prosthesis erodes upwards into the acetabulum to give pain and disability. Here the trial of a new bipolar prosthesis with a dynamic self-aligning outer head is described in 161 fractured necks of femur. No acetabular erosion has been seen with its use over four years

Five cases of syphilitic aortic aneurysm with erosion of the spinal column are reviewed. Four patients underwent operation. When erosion of the spine was mild or moderate, the aortic lesion only was treated. Aneurysm associated with extensive vertebral erosion was treated in two cases by anterior spinal fusion combined with replacement of the disc and part of the aorta. In one of these cases the spine was later reinforced by a posterior spinal fusion. One patient so treated died a week after operation. The patient who refused operation later developed a complete paraplegia

Osteoarthritis of the medial compartment of the knee often shows a specific pattern of anterior wear. Review of our revisions from a series of medial metal-backed Brigham unicondylar knee replacements performed between 1983 and 1989 showed that this wear pattern was common on the tibial polyethylene surface. We reviewed these cases retrospectively to compare the pattern of preoperative erosion with the wear of the prosthesis. In all 14 knees with severe anterior wear in a unicompartmental replacement, the prearthroplasty radiographs showed similar patterns, suggesting that the implanted tibial component may continue to be subjected to the same localised stresses that precipitated the failure of the original articular cartilage. Many tibial components implanted during the 1980s had an unacceptably thin anterior rim of polyethylene and it seems that greater thickness is essential at the anterior and peripheral margins of the tibial plateau

Using dried bones which could be tilted and rotated, we assessed the accuracy of published radiographic methods for measuring the migration of prosthetic acetabular components and compared the results with a new method. The new line linking acetabular margins was significantly more accurate for proximal migration than the teardrop, the sacroiliac line or the sacroiliac-symphysis line. For medial migration, a new line tangential to the brim and through the horizontal mid-point of the obturator foramen was more accurate than Kohler's line, the ilio-ischial line or the iliopubic line. In combination, the two new lines can give a more accurate assessment of acetabular erosion than previous methods, since they are less affected by the differences in rotation commonly found in a series of radiographs

Aims

The survival of humeral hemiarthroplasties in patients with relatively intact glenoid cartilage could theoretically be extended by minimizing the associated postoperative glenoid erosion. Ceramic has gained attention as an alternative to metal as a material for hemiarthroplasties because of its superior tribological properties. The aim of this study was to assess the in vitro wear performance of ceramic and metal humeral hemiarthroplasties on natural glenoids.

Partridge bands have been developed and marketed on the assumption that their ribbed under-surface would ensure less interference with periosteal and cortical blood flow than other cerclage systems. Three cases are reported of serious clinical complications from loss of cortical bone under the band, and interference with the external bridging callus response.

Calcified matrix that is being absorbed has a characteristic appearance. At the junction of the epiphysis and metaphysis in the rat tibia this appearance can be seen near capillary endothelium as well as under osteoclasts. It is concluded that absorption can take place under the walls of capillaries without the presence of osteoclasts.

Purpose of the study: Posterior glenoid erosio is a common finging in patients with degenerative joint disease of the shoulder. Anterior release is usually recommended, almost always with correction of the glenoid retroversion. There is no real consensus on the gravity of these posterior lesions nor on the appropriate attitude. The purpose of this study was to define the limitations of asymmetrical reaming during correction of excessive glenoid retroversion during total shoulder arthroplasty.

Material and methods: Five fresh cadaver shoulders were used. The size of the glenoid cavity and the humeral head were measured to select the optimal size for the glenoid implant. The scapula was embedded in resin. Posterior glenoid erosion was created by reaming to simulate wear producing retroversion greater than 15°. A control computed tomography (CT) was obtained to verify the lesion. The glenoid cavity was then prepared in the same manner as for prosthesis implantation, restoring neutral version to enable implantation of the prosthetic component of the size initially determined. A second CT was obtained to confirm the correction of the retroversion.

Results: The retroversion was corrected in all cases. At least one point of the implant penetrated the glenoid wall in all cases. In three cases, four points were outside the wall. In one case, reaming caused a fracture of the anterior glenoid rim. Finally, in one case, the size of the implant had to be reduced to avoid an oversized implant.

Discussion: The limitations for asymmetrical reaming to correct for posterior wear yet leave enough bone stock for implantation of a glenoid prosthesis are not defined. This study shows that asymmetrical reaming of the anterior rim of the glenoid cavity cannot satisfactorily correct for glenoid retroverson greater than 15° because of the frailness of the anterior wall and the risk the points will penetrate the rim. These complications compromise the primary stablity of the prosthesis and probably secondary short-term and mid-term stability.

Conclusion: If the glenoid retroversion is excessive (> 15°), it would be advisable to graft the posterior defect.

There is a surge of patients on the waiting-list for primary total hip replacement (THR), due to unprecedented reduction of elective activity caused by COVID-19. A higher incidence of femoral head collapse (FC) and acetabular erosion (AE) leading to increase in pain and instability as well as requirement of more complex surgery and potentially higher risk to patients was noted in this period. Rapidly progressive Arthritis (RPA) of the hip is a known entity often described as progression of joint space narrowing greater than 2mm over one year time period. The study aims to identify any potential relationship between waiting time and establishment of femoral head collapse and/ or acetabular erosion. A retrospective review of arthroplasty surgeon's waiting list during COVID. Serial hip radiographs recorded between February 2020 and February 2022 were analysed. FC was quantified as a percentage of the femoral head radius, while AE was assessed by drawing two parallel lines, one through both tear drops and the other through superior most aspect of intact acetabulum, parallel to the inter tear-drop line and expressed as percentage of normal side. Only 105 patients out of 264 patients added to the waiting list had elective arthroplasty for hip/knee. Only 35 patients out of 90 listed for THR, had the surgery. 36 of 90 (40%) were found to have developed FC and fitted the criteria for RPA. Acetabular erosion was seen in 19 (21%). Therefore 53% (19 of 36) of those who developed FC progressed to AE. Incidence of collapse was higher in females (32%), with mean age of 62 (range 51–81), compared to 21% in males with mean age 59 (range 53–87). Mean extent of femoral head collapse was 20% (10 – 44%). A significant proportion of patients added to waiting list during COVID developed RPA of the hip with 40% having femoral head collapse and 21% progressing to acetabular erosion leading to a complex case-mix. Patients on long waiting lists need regular x-ray checks/PROMS since significant proportion progress to FC and Acetabular Erosion

Aims. In patients with a failed radial head arthroplasty (RHA), simple removal of the implant is an option. However, there is little information in the literature about the outcome of this procedure. The aim of this study was to review the mid-term clinical and radiological results, and the rate of complications and removal of the implant, in patients whose initial RHA was undertaken acutely for trauma involving the elbow. Methods. A total of 11 patients in whom removal of a RHA without reimplantation was undertaken as a revision procedure were reviewed at a mean follow-up of 8.4 years (6 to 11). The range of motion (ROM) and stability of the elbow were recorded. Pain was assessed using a visual analogue scale (VAS). The functional outcome was assessed using the Mayo Elbow Performance Score (MEPS), the Oxford Elbow Score (OES), and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH). Radiological examination included the assessment of heterotopic ossification (HO), implant loosening, capitellar erosion, overlengthening, and osteoarthritis. Complications and the rate of further surgery were also recorded. Results. The indications for removal of the implant were stiffness in five patients, aseptic loosening in five, and pain attributed to the RHA in three. The mean time interval between RHA for trauma to removal was ten months (7 to 21). Preoperatively, three patients had overlengthening of the implant, three had capitellar erosion, six had HO, and four had radiological evidence of loosening. At the final follow-up, the mean the flexion-extension arc improved significantly by 38.2° (95% CI 20 to 59; p = 0.002) and the mean arc of prono-supination improved significantly by 20° (95% CI 0 to 72.5; p = 0.035). The mean pain VAS score improved significantly by 3.5 (95% CI 2 to 5.5; p = 0.004). The mean MEPS improved significantly by 27.5 (95% CI 17.5 to 42.5; p = 0.002). The mean OES improved significantly by 9 (95% CI 2.5 to 14; p = 0.012), and the mean DASH score improved significantly by 23.5 (95% CI 7.5 to 31.6; p = 0.012). Ten patients (91%) had HO and osteoarthritis. Two patients underwent further surgery due to stiffness and pain, respectively. Conclusion. Simple removal of the implant at revision surgery following a failed RHA introduced following trauma provides satisfactory mid-term results with an acceptable risk of complications. Osteoarthritis, instability, and radioulnar impingement were not problems in this series. Cite this article: Bone Joint J 2024;106-B(11):1327–1332

Superiorly eroded glenoids in cuff tear arthropathy represent a surgical challenge for reconstruction. The bone loss orientation and severity may influence glenoid component fixation. This computed-tomography study quantifies both the degree of erosion and orientation in superiorly eroded Favard E2 glenoids. We hypothesized that the erosion in E2 glenoids does not occur purely superiorly, rather, it is oriented in a predictable posterosuperior orientation with a largely semicircular line of erosion. Three-dimensional reconstructions of 40 shoulders with E2 glenoids (28 female, 12 male patients) at a mean age of 74 years (range, 56–88 years) were created from computed-tomography images. Point coordinates were extracted from each construct to analyze the morphologic structure. The anatomical location of the supra- and infraglenoid tubercle guided the creation of a superoinferior axis, against which the orientation angle of the erosion was measured. The direction and, thus, orientation of erosion was calculated as a vector. By placing ten point coordinates along the line of erosion and creating a circle of best fit, the radius of the circle was placed orthogonally against a chord that resulted by connecting the two outermost points along the line of erosion. To quantify the extent of curvature of the line of erosion between the paleo- and neoglenoid, the length of the radius of the circle of best fit was calculated. Individual values were compared against the mean of circle radii. The area of bony erosion (neoglenoid), was calculated as a percentage of the total glenoid area (neoglenoid + paleoglenoid). The severity of the erosion was categorized as mild (0% to 33%), moderate (34% to 66%), and severe erosion (>66%). The mean orientation angle between the vector of bony erosion and the superoinferior axis of the glenoid was 47° ± 17° (range, 14° – 74°) located in the posterosuperior quadrant of the glenoid, resulting in the average erosion being directed between the 10 and 11 o'clock position (right shoulder). In 63% of E2 cases, the line of erosion separating the paleo- and neoglenoids was more curved than the average of all bony erosions in the cohort. The mean surface area of the neoglenoid was 636 ± 247 mm2(range, 233 – 1,333 mm2) and of the paleoglenoid 311 ± 165 mm2(range, 123 – 820 mm2), revealing that, on average, the neoglenoids consume 67% of the total glenoid surface. The extent of erosion of the total cohort was subdivided into one mild (2%), 14 moderate (35%) and 25 severe (62%) cases. Using a clock-face for orientation, the average orientation of type E2 glenoid defects was directed between the 10 and 11 o'clock position in a right shoulder, corresponding to the posterosuperior glenoid quadrant. Surgeons managing patients with E2 type glenoids should be aware that a superiorly described glenoid erosion is oriented in the posterosuperior quadrant on the glenoid clock-face when viewed intra-operatively. Additionally, the line of erosion in 63% of E2 glenoids is substantially curved, having a significant effect on bone removal techniques when using commercially available augments for defect reconstruction

Knowledge of the premorbid glenoid shape and the morphological changes the bone undergoes in patients with glenohumeral arthritis can improve surgical outcomes in total and reverse shoulder arthroplasty. Several studies have previously used scapular statistical shape models (SSMs) to predict premorbid glenoid shape and evaluate glenoid erosion properties. However, current literature suggests no studies have used scapular SSMs to examine the changes in glenoid surface area in patients with glenohumeral arthritis. Therefore, the purpose of this study was to compare the glenoid articular surface area between pathologic glenoid cavities from patients with glenohumeral arthritis and their predicted premorbid shape using a scapular SSM. Furthermore, this study compared pathologic glenoid surface area with that from virtually eroded glenoid models created without influence from internal bone remodelling activity and osteophyte formation. It was hypothesized that the pathologic glenoid cavities would exhibit the greatest glenoid surface area despite the eroded nature of the glenoid and the medialization, which in a vault shape, should logically result in less surface area. Computer tomography (CT) scans from 20 patients exhibiting type A2 glenoid erosion according to the Walch classification [Walch et al., 1999] were obtained. A scapular SSM was used to predict the premorbid glenoid shape for each scapula. The scapula and humerus from each patient were automatically segmented and exported as 3D object files along with the scapular SSM from a pre-operative planning software. Each scapula and a copy of its corresponding SSM were aligned using the coracoid, lateral edge of the acromion, inferior glenoid tubercule, scapular notch, and the trigonum spinae. Points were then digitized on both the pathologic humeral and glenoid surfaces and were used in an iterative closest point (ICP) algorithm in MATLAB (MathWorks, Natick, MA, USA) to align the humerus with the glenoid surface. A Boolean subtraction was then performed between the scapular SSM and the humerus to create a virtual erosion in the scapular SSM that matched the erosion orientation of the pathologic glenoid. This led to the development of three distinct glenoid models for each patient: premorbid, pathologic, and virtually eroded (Fig. 1). The glenoid surface area from each model was then determined using 3-Matic (Materialise, Leuven, Belgium). Figure 1. (A) Premorbid glenoid model, (B) pathologic glenoid model, and (C) virtually eroded glenoid model. The average glenoid surface area for the pathologic scapular models was 70% greater compared to the premorbid glenoid models (P < 0 .001). Furthermore, the surface area of the virtual glenoid erosions was 6.4% lower on average compared to the premorbid glenoid surface area (P=0.361). The larger surface area values observed in the pathologic glenoid cavities suggests that sufficient bone remodelling exists at the periphery of the glenoid bone in patients exhibiting A2 type glenohumeral arthritis. This is further supported by the large difference in glenoid surface area between the pathologic and virtually eroded glenoid cavities as the virtually eroded models only considered humeral anatomy when creating the erosion. For any figures or tables, please contact the authors directly

Rheumatoid arthritis (RA) is an autoimmune disease that involves T and B cells and their reciprocal immune interactions with proinflammatory cytokines. T cells, an essential part of the immune system, play an important role in RA. T helper 1 (Th1) cells induce interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α), and interleukin (IL)-2, which are proinflammatory cytokines, leading to cartilage destruction and bone erosion. Th2 cells primarily secrete IL-4, IL-5, and IL-13, which exert anti-inflammatory and anti-osteoclastogenic effects in inflammatory arthritis models. IL-22 secreted by Th17 cells promotes the proliferation of synovial fibroblasts through induction of the chemokine C-C chemokine ligand 2 (CCL2). T follicular helper (Tfh) cells produce IL-21, which is key for B cell stimulation by the C-X-C chemokine receptor 5 (CXCR5) and coexpression with programmed cell death-1 (PD-1) and/or inducible T cell costimulator (ICOS). PD-1 inhibits T cell proliferation and cytokine production. In addition, there are many immunomodulatory agents that promote or inhibit the immunomodulatory role of T helper cells in RA to alleviate disease progression. These findings help to elucidate the aetiology and treatment of RA and point us toward the next steps. Cite this article: Bone Joint Res 2022;11(7):426–438