Patellar dislocation is a common presentation with a clear management pathway. Sometimes, however, what a patient experiences as the patella dislocating may, in fact, be ACL insufficiency. We reviewed case notes and imaging of 315 consecutive ACL reconstructions, collecting data on the date and mechanism of injury, time to MRI, and reconstruction. We noted cases initially diagnosed as patellar dislocation. 25 of 315 (7.9%) patients were initially diagnosed with a patellar dislocation. Subsequently, however, MRI scans revealed no evidence of patellar dislocation and instead showed ACL rupture with pathognomonic pivot-shift bony oedema. The false patella dislocation group were 32% female and had an average age of 25; the rest of the group average age was 27.1 and there were a lower proportion of females; 21%. The false patella instability patients had a median waiting time of 412 days from injury to operation (range: 70-2445 days), compared to 392 days (range: 9 – 4212 days) for rest of the patients. 5 of the remaining 290 had MRIs showing patella oedema with medial patello-femoral ligament injury in addition to their ACL rupture. From our literature search this is a new finding which shows that ACL rupture can present with symptoms suggestive of patellar dislocation. These findings raise the risk that there are a group of people who have been diagnosed with patellar instability who instead have ACL insufficiency and so are at risk of meniscal and chondral damage. Further research should analyse those diagnosed with patellar instability to quantify missed ACL injuries

Aims. The prevalence of osteoarthritis (OA) associated with instability of the shoulder ranges between 4% and 60%. Articular cartilage is, however, routinely assessed in these patients using radiographs or scans (2D or 3D), with little opportunity to record early signs of cartilage damage. The aim of this study was to assess the prevalence and localization of chondral lesions and synovial damage in patients undergoing arthroscopic surgery for instablility of the shoulder, in order to classify them and to identify risk factors for the development of glenohumeral OA. Methods. A total of 140 shoulders in 140 patients with a mean age of 28.5 years (15 to 55), who underwent arthroscopic treatment for recurrent glenohumeral instability, were included. The prevalence and distribution of chondral lesions and synovial damage were analyzed and graded into stages according to the division of the humeral head and glenoid into quadrants. The following factors that might affect the prevalence and severity of chondral damage were recorded: sex, dominance, age, age at the time of the first dislocation, number of dislocations, time between the first dislocation and surgery, preoperative sporting activity, Beighton score, type of instability, and joint laxity. Results. A total of 133 patients (95%) had synovial or chondral lesions. At the time of surgery, shoulders were graded as having mild, moderate, and severe OA in 55 (39.2%), 72 (51.4%), and six (4.2%) patients, respectively. A Hill-Sachs lesion and fibrillation affecting the anteroinferior glenoid cartilage were the most common findings. There was a significant positive correlation between the the severity of the development of glenohumeral OA and the patient’s age, their age at the time of the first dislocation, and the number of dislocations (p = 0.004, p = 0.011, and p = 0.031, respectively). Conclusion. Synovial inflammation and chondral damage associated with instability of the shoulder are more prevalent than previously reported. The classification using quadrants gives surgeons more information about the chondral damage, and could explain the pattern of development of glenohumeral OA after stabilization of the shoulder. As the number of dislocations showed a positive correlation with the development of OA, this might be an argument for early stabilization. Cite this article: Bone Joint J 2024;106-B(10):1125–1132

Aims

The purpose of this study was to evaluate the mid-term outcomes of autologous matrix-induced chondrogenesis (AMIC) for the treatment of larger cartilage lesions and deformity correction in hips suffering from symptomatic femoroacetabular impingement (FAI).

The April 2024 Knee Roundup³⁶⁰ looks at: Challenging the status quo: re-evaluating the impact of obesity on unicompartmental knee arthroplasty outcomes; Timing matters: the link between ACL reconstruction delays and cartilage damage; Custom fit or off the shelf: evaluating patient outcomes in tailored versus standard knee replacements; Revolutionizing knee replacement: a comparative study on robotic-assisted and computer-navigated techniques; Pre-existing knee osteoarthritis and severe joint depression are associated with the need for total knee arthroplasty after tibial plateau fracture in patients aged over 60 years; Modern digital therapies?; A matched study on fracture rates following knee replacement surgeries;

For chondral damage in younger patients, surgical best practice is microfracture, which involves drilling into the bone to liberate the bone marrow. This leads to a mechanically inferior fibrocartilage formed over the defect as opposed to the desired hyaline cartilage that properly withstands joint loading. While some devices have been developed to aid microfracture and enable its use in larger defects, fibrocartilage is still produced and there is no clear clinical improvement over microfracture alone in the long term. Our goal is to develop 3D printed devices, which surgeons can implant with a minimally invasive technique. The scaffolds should match the functional properties of cartilage and expose endogenous marrow cells to suitable mechanobiological stimuli in-situ, in order to promote healing of articular cartilage lesions before they progress to osteoarthritis, and rapidly restore joint health and mobility. Importantly, scaffolds should direct a physiological host reaction, instead of a foreign body reaction, associated with chronic inflammation and fibrous capsule formation, negatively influencing the regenerative outcome. Our novel silica/polytetrahydrofuran/polycaprolactone hybrids were prepared by sol-gel synthesis and scaffolds were 3D printed by direct ink writing. 3D printed hybrid scaffolds with pore channels of ~250 µm mimic the compressive behaviour of cartilage. Our results show that these scaffolds support human bone marrow stem/stromal cell (hMSC) differentiation towards chondrogenesis in vitro under hypoxic conditions to produce markers integral to articular cartilage-like matrix evaluated by immunostaining and gene expression analysis. Macroscopic and microscopic evaluation of subcutaneously implanted scaffolds in mice showed that scaffolds caused a minimal resolving inflammatory response. Our findings show that 3D printed hybrid scaffolds have the potential to support cartilage regeneration. Acknowledgements: Authors acknowledge funding provided by EPSRC grant EP/N025059/1

Introduction. Patellofemoral instability is one of the most common presentations to a children's orthopaedic clinic. Recurrent patellar dislocations and instability episodes are painful, disabling and increase the risk of irreversible chondral damage. The medial patellofemoral ligament is the primary static stabiliser to prevent lateral dislocation of the patella and is almost always torn or attenuated in these cases. Reconstruction of this ligament is commonly performed using autologous hamstring tendon however there has been some interest recently in use of quadriceps tendon as a graft. Children with patellar instability also present unique challenges due to the small size of the patella and the presence of open growth plates which may require adaptations to the common techniques. Methods. Patients undergoing medial patellofemoral ligament reconstruction using quadriceps tendon autograft were identified using electronic theatre records. Prospectively collected clinical records and imaging findings were reviewed and underlying pathology, additional procedures at time of MPFL reconstruction, current function and need for further revision surgery determined. Results. Between January 2019 and August 2023, 50 MPFL reconstructions were performed in 37 children using partial thickness quadriceps autograft. Patient age at time of surgery ranged from 5 to 17 years (median age 13 years). The technique was utilised for a variety of indications including recurrent traumatic and habitual patellofemoral instability, fixed dislocations, and revision MPFL reconstruction. Conclusion. Partial thickness quadriceps tendon autograft can be used safely to primarily reconstruct the medial patellofemoral ligament in paediatric population, including those children with open growth plates. It also has utility in revision cases following previous failed hamstring MPFL reconstruction. We have noted that the younger the child, the more distal to the physis lies the femoral point of isometricity, rendering this a safe and reproducible treatment in this age group. Use of this technique has increased in our unit as we have observed that patients seem to be satisfied with their clinical and functional outcomes with a low incidence of short- and medium-term complications

Aims

The aim of this study was to evaluate the association between chondral injury and interval from anterior cruciate ligament (ACL) tear to surgical reconstruction (ACLr).

Abstract. Introduction. The aim of this study was to determine the factors affecting return to sport (RTS) and career longevity of elite athletes after microfracture of the knee. Methods. A retrospective review of a consecutive series of elite athletes with chondral injuries in the knee treated with microfracture was undertaken. RTS was defined as competing in at least one event at professional level or national/ international level in amateur sport. Demographic, pre, intra and post operative factors affecting RTS were analysed. Results. Fifty six athletes, including 35 (62.5%) footballers and 14 (25.0 %) rugby players, with a mean age 24.8 (+/− 3.9) years, were included. 18 (32.1 %) of chondral injuries were secondary to trauma, 20 (35.7 %) post meniscectomy, 9 (16.1%) post anterior cruciate ligament (ACL) reconstruction and 9 (16.1%) idiopathic. Fifty (89.3%) of athletes RTS at a mean time of 10.0 (+/−5.8) months. 43 (86.0%) athletes were still playing at 2 years. At 5 years 25 (59.5%) of the players who had RTS and had surgery more than 5 years ago were still playing professional sport. Factors associated with not playing at 5 years were cartilage lesions >1.5cm2(52.4% vs 66.7%), more than 1 lesion (35.7% vs74.1%), lateral meniscal surgery (42.1% vs 73.7%) and effusion on RTS (47.7% vs 72.2%). Conclusion. Over 89 % of elite athletes returned to professional sport after microfracture in the knee. However, the ability to continue playing is affected by several factors such as the extent of the chondral damage and recurrent effusions

Aims

Hip arthroscopy (HA) has become the treatment of choice for femoroacetabular impingement (FAI). However, less favourable outcomes following arthroscopic surgery are expected in patients with severe chondral lesions. The aim of this study was to assess the outcomes of HA in patients with FAI and associated chondral lesions, classified according to the Outerbridge system.

Femoroacetabular impingement is a prearthritic deformity frequently associated with early chondral damage. Several techniques exist for restoring larger cartilage defects. While AMIC proved to be an effective treatment in knee and ankle, there are only short-term data available in hip. This study aimed to investigate the mid-term clinical outcome of patients with chondral lesions treated by AMIC and evaluate the quality of repair tissue via MRI. This retrospective, single center study includes 18 patients undergoing surgical hip dislocation for FAI between 2013 and 2016. Inclusion criteria were: cam or pincer-type FAI, femoral or acetabular chondral lesions > 1 cm. 2. , (IRCS III-IV). Due to exclusion criteria and loss-to-follow-up 9 patients (10 hips) could be included. Patient reported outcome measures included Oxford Hip Score (OHS) & Core Outcome Measure Index (COMI)). MRIs were evaluated using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. None of the patients underwent revision surgery except screw removals from the greater trochanter. Followup data indicate a satisfactory to good hip function at 5 years: PROMS improved from pre- to postop at 5 years: OHS from 38.1 to 43.4, COMI from to 1.8 and UCLA from 4 to 8.1 respectively. MOCART score was 67.5 postoperatively. Subgrouping showed slightly better results for acetabular defects (Ø 69.4) compared femoral defects (Ø 60). Based on the reported mid-term results, we consider AMIC as a valuable treatment option for larger chondral defects of the hip

Arthroscopic hip surgery is increasingly common in Australia. Hip arthroscopy is indicated for a range of diagnostic and therapeutic purposes, including labral tears, capsular laxity and femoral-acetabular impingement (FAI). Despite this, previous cohort studies aiming to characterise hip pathology seen on arthroscopic examination are mostly limited to patients with known diagnoses of FAI. Therefore, little is known of the native articular wear patterns encountered in other disease states. Therefore, we aimed to define common osteochondral wear patterns for a cohort of patients managed via hip arthroscopy. We retrospectively analysed intraoperative data for 1127 patients managed via hip arthroscopy between 2008 and 2013, for either therapeutic or diagnostic purposes. Intraoperative data was categorized by location (A-E as defined by Fontana et al. 2016) and chondral damage (0-4 scale as defined by Beck et al. 2005) with respect to both acetabulum and femoral head. Data for 1127 patients were included. Location of acetabular chondral pathology was variable with locations C. 1. and D. 1. representing the most common regions of damage. Labral tears predominated in locations C and D. Femoral chondral pathology was evenly distributed. The degree of femoral chondral injury was predominantly grade 1, whilst acetabular wear was evenly distributed. Large proportions of wear were observed at the peripheral superior and anterior regions of the lunate surface of the acetabulum in keeping with prior works. However, we observed higher rates of central wear and lower rates of grade 4 acetabular damage extending into superior/posterior zones, in our cohort. Our work characterises common articular wear patterns encountered at the time of hip arthroscopy. Further inquiry into the natural history of osteochondral lesions is needed to better understand and manage these conditions

Abstract. Introduction. High posterior tibial slope (PTS) has been recognised as a risk factor for anterior cruciate ligament rupture and graft failure. This prospective randomised study looked at intra-operative findings of concomitant intra-articular meniscal and chondral injuries during a planned ACL reconstruction. Material and Methods. Prospective data was collected as part of a randomised trial for ACL reconstruction techniques. Intra-operative data was collected and these findings were compared with the PTS measured on plain radiograph by a single person twice through a standardised technique and intra-observer analysis was performed. Results. 49 confirmed ACL rupture patients were in the trial. The average age was 34 (23–66) years and 12 patients were female. 17 patients (34%) had PTS of 12 degrees or more. The intra-observer analysis for PTS measurements in a 2-sided paired T test, showed a mean difference of 0.03 degrees with a P value = 0.83. 23 patients had medial meniscal pathology identified, 15 (65%) had a PTS <12 degrees. 16 patients had lateral meniscus pathology and 9 (56%) had a PTS <12 degrees. Chondral damage did not appear significantly different in the two groups (<12 degrees 15% vs >12 degrees 23%). Conclusion. In this sample, a PTS >12 degrees was not associated with a higher incidence of meniscal or chondral damage after a confirmed ACL rupture

There has been a marked increase in the number of hip arthroscopies performed over the past 16 years, primarily in the management of femoroacetabular impingement (FAI). Insights into the pathoanatomy of FAI, and high-level evidence supporting the clinical effectiveness of arthroscopy in the management of FAI, have fuelled this trend. Arthroscopic management of labral tears with repair may have superior results compared with debridement, and there is now emerging evidence to support reconstructive options where repair is not possible. In situations where an interportal capsulotomy is performed to facilitate access, data now support closure of the capsule in selective cases where there is an increased risk of postoperative instability. Preoperative planning is an integral component of bony corrective surgery in FAI, and this has evolved to include computer-planned resection. However, the benefit of this remains controversial. Hip instability is now widely accepted, and diagnostic criteria and treatment are becoming increasingly refined. Instability can also be present with FAI or develop as a result of FAI treatment. In this annotation, we outline major current controversies relating to decision-making in hip arthroscopy for FAI.

Cite this article: Bone Joint J 2022;104-B(5):532–540.

This study aimed to analyse the incidence, the operative findings and outcomes of hip arthroscopy after periacetabular osteotomy (PAO). We conducted a retrospective study of prospective collected data to report the operative findings and outcomes of hip arthroscopy for recurrent pain following PAO for acetabular dysplasia. Demographic data, radiographic and arthroscopic findings were analysed. Pre- and post-operative patient reported outcome measures (PROMs) were collected. Of 184 PAO patients, 15 hips in 15 patients (8.2%) underwent post-PAO hip arthroscopy with 2 males and 13 females at a mean time of 3.9 ±2.9(0.3–10) years. Hip arthroscopy findings included labral tears (15 hips, 100%), chondral damage (11 hips, 73%) with one Beck 1, two Beck 2, four Beck 4, and four Beck 5 damage. There were 8 (53%) isolated labral debridement, 7 (47%) labral repair, and 2 (13%) adhesiolysis. A femoral osteochondroplasty was performed in 4 (27%) hips. Four hips (27%) were finally converted to total hip replacement at a mean delay of 2.3 ±1.4 (0.7–3.2) years post hip arthroscopy and these 4 patients were significantly older than those who were not (p=0.02). There were no significant differences in PROMs pre and post hip scope. 8.2% of patients undergoing a PAO required a hip scope for persistent hip pain. Common post-PAO hip arthroscopy findings included labral tears, chondral changes and femoroacetabular impingement. 27% of patients finally underwent conversion to total hip replacement at a mean follow-up of 4.5 years post hip scope

Chondral hip injuries are common secondary to femoroacetabular impingement (FAI). Treatment with arthroscopic procedures including chondroplasty and microfracture is becoming increasingly common but literature is limited to case series at specialist centres. The aim of this study is to compare outcomes of arthroscopic acetabular chondral procedures using the NAHR dataset (UK) which represents the largest series to date. All adult Arthroscopies recorded in the NAHR from Jan 2012 were available for inclusion. Exclusions included significant arthritis and femoral, complex or revision chondral procedures. Patients completed iHOT-12 & EQ-5D Index pre-operatively, 6 and 12 months. Data was analysed using T-test/ANOVA for between group/within group for continuous variables, chi square test for categorical variables and linear regression model for multivariable analysis. 5,752 patients, 60% female. 27% Chondroplasty, 5% Microfracture, 68% no Chondral Procedure. Maximum acetabular Outerbridge classification 14% Grade 1, 15% Grade 2, 17% Grade 3, 8% Grade 4, 9% no damage, not recorded in 37%. Higher proportion of Cam impingement in association with chondral treatments and a larger proportion of patients with no impingement recorded in group with no chondral procedures. There was a significant improvement versus baseline for all groups in iHOT-12 and EQ-5D Index (p<0.0001) including Grade four Outerbridge. There was significantly greater improvement in pre-operative scores in the chondroplasty group compared to the microfracture group at 6 and 12 months (p<0.05). Following hip arthroscopy, patients with chondral procedures experienced improved outcome scores despite Outerbridge 4 chondral damage. Presence of cam lesions are more commonly associated with chondral treatments. Good outcomes were maintained up to 12 months for chondral procedures, regardless of age or impingement pathology however pincers improved less and patients over 40 years took longer to see improvement

As our understanding of hip function and disease improves, it is evident that the acetabular fossa has received little attention, despite it comprising over half of the acetabulum’s surface area and showing the first signs of degeneration. The fossa’s function is expected to be more than augmenting static stability with the ligamentum teres and being a templating landmark in arthroplasty. Indeed, the fossa, which is almost mature at 16 weeks of intrauterine development, plays a key role in hip development, enabling its nutrition through vascularization and synovial fluid, as well as the influx of chondrogenic stem/progenitor cells that build articular cartilage. The pulvinar, a fibrofatty tissue in the fossa, has the same developmental origin as the synovium and articular cartilage and is a biologically active area. Its unique anatomy allows for homogeneous distribution of the axial loads into the joint. It is composed of intra-articular adipose tissue (IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells, which participate in the inflammatory cascade after an insult to the joint. Hence, the fossa and pulvinar should be considered in decision-making and surgical outcomes in hip preservation surgery, not only for their size, shape, and extent, but also for their biological capacity as a source of cytokines, immune cells, and chondrogenic stem cells.

Cite this article: Bone Joint Res 2020;9(12):857–869.