Aims

The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process.

Partial meniscectomy patients have a greater likelihood for the development of early osteoarthritis (OA). To prevent the onset of early OA, patient-specific treatment algorithms need to be created that predict patient risk to early OA after meniscectomy. The aim of this work was to identify patient-specific risk factors in partial meniscectomy patients that could potentially lead to early OA. Partial meniscectomy patients operated between 01/2017 and 12/2019 were evaluated in the study (n=317). Exclusion criteria were other pathologies or surgeries for the evaluated knee and meniscus (n = 114). Following informed consent, an online questionnaire containing demographics and the “Knee Injury and Osteoarthritis Outcome Score” (KOOS) questionnaire was sent to the patient. Based on the KOOS pain score, patients were classified into “low” (> 75) and “high” (< 75) risk patients, indicating risk to symptomatic OA. The “high risk” patients also underwent a follow-up including an MRI scan to understand whether they have developed early OA. From 203 participants, 96 patients responded to the questionnaire (116 did not respond) with 61 patients considered “low-risk” and 35 “high-risk” patients. Groups that showed a significant increased risk for OA were patients aged > 40 years, females, overweight (BMI >25 kg/m2 ≤ 30 kg/m2), and smokers (*p < 0.05). The “high-risk”-follow-up revealed a progression of early osteoarthritic cartilage changes in seven patients, with the remaining nineteen patients showing no changes in cartilage status or pain since time of operation. Additionally, eighteen patients in the high-risk group showed a varus or valgus axis deviation. Patient-specific factors for worse postoperative outcomes after partial meniscectomy and indicators for an “early OA” development were identified, providing the basis for a patient-specific treatment approach. Further analysis in a multicentre study and computational analysis of MRI scans is ongoing to develop a patient-specific treatment algorithm for meniscectomy patients

Aims. To determine the relationship between articular cartilage status and clinical outcomes after medial opening-wedge high tibial osteotomy (MOHTO) for medial compartmental knee osteoarthritis at intermediate follow-up. Methods. We reviewed 155 patients (155 knees) who underwent MOHTO from January 2008 to December 2016 followed by second-look arthroscopy with a mean 5.3-year follow-up (2.0 to 11.7). Arthroscopic findings were assessed according to the International Cartilage Repair Society (ICRS) Cartilage Repair Assessment (CRA) grading system. Patients were divided into two groups based on the presence of normal or nearly normal quality cartilage in the medial femoral condyle: good (second-look arthroscopic) status (ICRS grade I or II; n = 70), and poor (second-look arthroscopic) status (ICRS grade III or IV; n = 85) groups at the time of second-look arthroscopy. Clinical outcomes were assessed using the International Knee Documentation Committee (IKDC) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 36-Item Short Form survey. Results. Significant improvements in all clinical outcome categories were found between the preoperative and second-look arthroscopic assessments in both groups (p < 0.001). At the latest follow-up, the mean IKDC and WOMAC scores in the good status group further improved compared with those at the time of second-look arthroscopic surgery (p < 0.001), which was not shown in the poor status group. The mean IKDC (good status, 72.8 (SD 12.5); poor status, 64.7 (SD 12.1); p = 0.002) and mean WOMAC scores (good status, 15.7 (SD 10.8); poor status, 21.8 (SD 13.6); p = 0.004) significantly differed between both groups at the latest follow-up. Moreover, significant correlations were observed between ICRS CRA grades and IKDC scores (negative correlation; p < 0.001) and WOMAC scores (positive correlation; p < 0.001) at the latest follow-up. Good cartilage status was found more frequently in knees with the desired range of 2° to 6° valgus correction than in those with corrections outside this range (p = 0.019). Conclusion. Second-look arthroscopic cartilage status correlated with clinical outcomes after MOHTO at intermediate-term follow-up, despite the relatively small clinical differences between groups. Cite this article: Bone Joint J 2021;103-B(11):1686–1694

Aims

In the last decade, interest in partial knee arthroplasties and bicruciate retaining total knee arthroplasties has increased. In addition, patient-related outcomes and functional results such as range of movement and ambulation may be more promising with less invasive procedures such as bicompartmental arthroplasty (BCA). The purpose of this study is to evaluate clinical and radiological outcomes after a third-generation patellofemoral arthroplasty (PFA) combined with a medial or lateral unicompartmental knee arthroplasty (UKA) at mid- to long-term follow-up.

Aims

To explore the clinical relevance of joint space width (JSW) narrowing on standardized-flexion (SF) radiographs in the assessment of cartilage degeneration in specific subregions seen on MRI sequences in knee osteoarthritis (OA) with neutral, valgus, and varus alignments, and potential planning of partial knee arthroplasty.

Aims. Hip displacement, common in patients with cerebral palsy (CP), causes pain and hinders adequate care. Hip reconstructive surgery (HRS) is performed to treat hip displacement; however, only a few studies have quantitatively assessed femoral head sphericity after HRS. The aim of this study was to quantitatively assess improvement in hip sphericity after HRS in patients with CP. Methods. We retrospectively analyzed hip radiographs of patients who had undergone HRS because of CP-associated hip displacement. The pre- and postoperative migration percentage (MP), femoral neck-shaft angle (NSA), and sphericity, as determined by the Mose hip ratio (MHR), age at surgery, Gross Motor Function Classification System level, surgical history including Dega pelvic osteotomy, and triradiate cartilage status were studied. Regression analyses using linear mixed model were performed to identify factors affecting hip sphericity improvement. Results. A total of 108 patients were enrolled. The mean preoperative MP was 58.3% (SD 31.7%), which improved to 9.1% (SD 15.6%) at the last follow-up. NSA and MHR improved from 156.5° (SD 11.5°) and 82.3% (SD 8.6%) to 126.0° (SD 18.5°) and 89.1% (SD 9.0%), respectively. Factors affecting the postoperative MHR were preoperative MP (p = 0.005), immediate postoperative MP (p = 0.032), and history of Dega osteotomy (p = 0.046). Conclusion. We found that hip sphericity improves with HRS. Preoperative MP, reduction quality, and acetabular coverage influence femoral head remodelling. We recommend that surgeons should consider intervention early before hip displacement progresses and that during HRS, definite reduction and coverage of the femoral head should be obtained. Cite this article: Bone Joint J 2021;103-B(1):198–203

Aims

The purpose of our study was to determine whether mesenchymal stem cells (MSCs) are an effective and safe therapeutic agent for the treatment of knee osteoarthritis (OA), owing to their cartilage regeneration potential.

In knee osteoarthritis (OA) patients, a focal cartilage defect is commonly found, especially in the medial compartment. In addition, cartilage softening is often observed at the defect rim. Both factors may alter the loading distribution and thereby the contact pressures, previously related to cartilage degeneration. To determine contact pressure in-vivo during motion, computational modelling can be used. The aim of this study was to analyse knee cartilage pressures during walking in healthy and damaged cartilage using a multi-scale modelling approach. Using 3D motion capture and musculoskeletal models, multi-body simulations of the stance phase of gait calculated knee kinematics and muscle, ligament and contact forces. These were subsequently imposed to a finite element (FE) model including tibial and femoral bones and cartilage. FE analyses were performed using intact cartilage as well as including a medial tibial cartilage defect, with and without softening of the defect rim. Specifically during loading response, a medial cartilage defect reduced the contact surface (−28%) and thereby increased the contact pressure (+33%) compared to intact cartilage, particularly on the medial compartment (+75% in contact pressure). Including softening of the cartilage rim increased the contact area (+22%) and decreased contact pressures (−9%) compared to the defect. This indicates that a focal defect increases the cartilage loading. This is partially compensated by softening of the cartilage rim. Therefore, the role of focal defects in altered cartilage loading and consequent OA development always needs to be discussed acknowledging the cartilage status at the defect rim

Aims

The aim of this study was to evaluate the long-term clinical and radiographic outcomes of the Birmingham Interlocking Pelvic Osteotomy (BIPO).

Summary Statement. This work proved by prospective clinical and radiological controlled study that the best regimen for treatment of early KOA is combination of NSAIDS, physiotherapy, vasoprotective and vasodilator drugs, and alendronate. Introduction. There is controversy in the literatures regarding the best treatment for early knee osteoarthritis because there is a more controversy regarding the initiating factor of KOA The Objectives of this work were to evaluate the efficacy of various treatment regimens for the prevention of progression of early knee osteoarthritis (KOA). Also, to elucidate the factors for initiation and progression of KOA. Patients and Methods. Four groups of 50 patients with early KOA were treated with four treatment regimens. The first group (control) received analgesics as needed for one year. The second group received non steroidal anti-inflammatory drugs (NSAIDS) plus physiotherapy for one month; with analgesics as needed for the rest of the year. The third group received NSAIDS plus physiotherapy, plus vasoprotective and vasodilator drugs for one month; vasoprotective and vasodilator drugs for the next six months, and analgesics as needed for the rest of the year. The fourth group received NSAIDS plus physiotherapy, plus vasoprotective and vasodilator drugs plus alendronate for one month; vasoprotective and vasodilator drugs plus alendronate for the next six months; and analgesics as needed for the rest of the year. The age of the patients was from 40 to45years. There were 25 males and 25 females in each group. Patients with causes of secondary KOA (e.g. rheumatoid, gouty, traumatic, etc.) were excluded. All patients were subjected to Pre- and post treatment regimens clinical and radiological evaluation Clinical evaluation included history of progressive knee pain for 3–6weeks, limping, Visual analog pain score, tenderness, and knee range of motion. Radiological evaluation included 1.0 T MRI which was performed using proton density-weighted, fat-suppressed sequences. BML size and cartilage status were scored in the same sub regions according to the WORMS system. Results. Progression of KOA in the first, second, third, and fourth group were 66%, 55%, 25%, and 19% of patients respectively No sex difference was detected. Conclusion. The best treatment regimen for early KOA is combination of NSAIDS, physiotherapy, vasoprotective and vasodilator drugs, and alendronate. Vascular and local osteoporotic factors may play a major role in progression of KOA

The treatment of hip dysplasia should be customised for patients individually based on radiographic findings, patient age, and the patient’s overall articular cartilage status. In many patients, restoration of hip anatomy as close to normal as possible with a PAO is the treatment of choice.

Cite this article: Bone Joint J 2013;95-B, Supple A:21–5.

Direct arthroscopic cartilage assessment remains the gold standard. It is recommended by the International Cartilage Repair Society (ICRS) to systematically assess cartilage status during arthroscopy but this examination is highly subjective, poorly reproducible, time-consuming and lacks precision. US has shown good potential for cartilage evaluation but is limited in extra-articular conditions. It is also difficult to manually maintain a perfect perpendicularity between the ultrasound beam and the curved surface of the cartilage. Therefore, we have developed a navigated intra-articular US probe (NIAUS). The NIAUS probe could contribute to a more exhaustive and direct intra-articular evaluation of cartilage integrity. Navigation enables control of the US echo pulse perpendicularity and its localisation relative to the joint. Our objectives were (1) to evaluate automatic cartilage thickness measurement with the NIAUS probe in comparison to high definition MRI on cartilage samples, (2) to generate a real-time 3D map of the thickness parameter on samples, and (3) to demonstrate the feasibility of a full NIAUS probe cartilage scan on a specimen distal femur in arthroscopic conditions. The NIAUS probe is a 4.5mm probe consisting of a 64 element linear array transducer with a central frequency of 13 MHz and a motorised head. The NIAUS probe is navigated. The rotating US head position is controlled by navigation in order to enable constant perpendicular acquisition of cartilage. The NIAUS probe thickness measurement (1) was evaluated on bone and cartilage samples of 9 tibial plateaus. The cartilage thickness was measured via automatic segmentation. Each sample was also scanned in a high resolution MRI (4,7 Tesla) and cartilage thickness was semi-automatically extracted for comparison. During NIAUS scan, (2) a visual 3D map was generated. Finally (3), we scanned two distal femurs with the NIAUS probe in arthroscopic navigated conditions on one specimen and a 3D map of the distal femur thickness was generated in real time. NIAUS thickness measurement (1) absolute error compared to MRI for 9 plateaus ranged from 0.15mm to 0.32mm in median, p25=0.07 and 0.18, p75=0.28 and 0.5 respectively. 3D maps of the sample cartilage thickness (2) were generated in real time during the NIAUS scan. The cadaveric procedure (3) was conducted without incident via the two anterior portals and a 3D map of the distal femurs cartilage thickness was generated. A precise US arthroscopic grading and scoring of cartilage during surgery could help for better standardisation, prediction of results and making “live” decisions. Our in vitro experiment shows good results compared to MRI for NAIUS cartilage thickness measurement, and our cadaveric study demonstrate the feasibility of a NIAUS scan in arthroscopic conditions. Our results are encouraging and a clinical trial is currently being designed for preliminary in vivo NIAUS evaluations of cartilage thickness compared to MRI

90% of young patients that develop DJD of the hip have an underlying structural problem, most frequently hip dysplasia. The structural problem results in decreased contact area, increased contact stresses about the anterior and lateral acetabulum and femoral head and results in labral pathology, early cartilage damage and if left untreated leads to end stage hip arthritis. Despite the optimism of alternative bearing surfaces and highly cross linked polyethylene, THA should still be discouraged in young patients. Many patients with symptomatic hip dysplasia in the absence of arthritis will benefit from joint preservation. The goal of treatment should be restoration of anatomy as close to normal as possible. The Bernese PAO is the preferred technique in many centres in North America and Europe because of its balance between minimal exposure, complications, and ability to provide optimal correction. The ideal patient for a PAO is young, has no arthritis, is not obese (BMI <30) and has poorly covered femoral head where congruency is possible. A PAO has advantages over other osteotomies and include: . 1). Performed through one incision without violation of the abductors. 2). Pelvic ring and an outlet, are not disrupted. 3). Posterior column is preserved. 4). Allow multidirectional correction. 5). Can perform capsulotomy to assess the labrum and check for impingement. The results of the osteotomy have been encouraging with up to 60% survivorship free from total hip arthroplasty at 20 years. Most studies show improvement in pain and function, improvement in radiographic coverage of the femoral head with no improvement in range of motion. Treatment should be individualised to each patient based on radiographic findings, age and cartilage status and restoration of anatomy as close to normal as possible should be the ideal treatment, most commonly in the form of a periacetabular osteotomy

Introduction. Ectopic ossification (EO) at the acetabular rim has been suggested to be associated with pincer impingement and to lead to ossification of the labrum. However, this has never been substantiated with histological, radiographic and MRI findings in large cohorts of patients. We hypothesized that it is more a bone apposition of the acetabular rim and that it occurs more frequently in coxa profunda (CP) hips. Materials and Methods. In the first part, a cohort of 20 hips with this suspected ectopic rim ossification (EO) pattern were identified. The radiographic features that could be associated with this ossification pattern were described and evaluated by a histologic examination of intra-operative samples taken from the rim trimming. In the second part, we assessed the prevalence of this ectopic ossification process in a cohort of 203 patients treated for FAI. Results. Histologic examination revealed that new acetabular bone formation was either overgrowing the non-ossified labrum or moving it away from the native rim. Radiologically, this was associated with an “indentation sign” and/or a “double line sign”. There were no specimens that had shown any evidence of labral ossification. EO was found in 26 hips (18%) of the second cohort. Twenty of 26 hips (77%) with EO had CP morphology and 29% of CP hips had EO signs. In contrast, only 6 non-profunda hips (8%) were associated with EO. There was a high correlation between XR and MRI findings as >80% of XR findings were confirmed on MRI. Sixty-nine hips had CP morphology. The double line sign (N = 13), the indentation sign (N = 12) and a prominent lateral rim (N = 11) were found. Hips with an EO pattern were found in patients that were significantly older than those without EO (p = 0.01). The acetabular characteristics of the EO groups were not significantly different from the CP hips without EO. The femoral characteristics were significantly different between groups with lower neck shaft angles (128° vs 134°;p = 0,0002) and shorter femoral necks lengths (62mm vs 65mm; p = 0,04)) in the EO group. The mean Tonnis classification was not significantly different (p = 0,18). In addition, the mean acetabular cartilage degeneration status was not different between both groups (p = 0,9). Rim trimming down to the native acetabular bone was done in all cases either by arthroscopy (N = 40) or open surgical dislocation (N = 17). Discussion. Ectopic ossification of the acetabular rim predominantly occurs in CP and is associated with specific anatomic features of the proximal femur. This type of impingement seems to be different and less aggressive than other described impingement processes. The double line sign and indentation sign are highly indicative for this EO process and are indicative for a longstanding impingement problem. Trimming of the acetabular rim should be conducted

Purpose. To assess performance of a polyurethane scaffold designed to facilitate regrowth of tissue after irreparable partial meniscus tissue loss. Methods. Fifty-two subjects with irreparable medial or lateral meniscus tissue lesions with intact rim, presence of both horns and stable, well aligned knees, were treated with the scaffold. Tissue ingrowth was assessed using dynamic contrast enhanced MRI (DCE-MRI) at 3 months (n=43), and by histological examination of biopsies (n=44) at 12 months relook arthroscopy. Cartilage status on MRI at 1week, 3, 12 and 24 months, and clinical outcomes were assessed from baseline to 24 months using Visual Analogue Scale (VAS), Knee and Osteoarthritis Outcome Score (KOOS), Lysholm and International Knee Documentation Committee (IKDC). Results. Clinically and statistically significant improvements on all outcome scores were observed at 6, 12 and 24 months. On MRI, stable or improved ICRS scores in all but 3 subjects (n=40) at 24 months were observed, with no signs of scaffold related cartilage damage. All biopsies contained vital material, with no signs of necrosis, cell death (presence of cell pods, ghost cells, cells with defragmented nuclei), or adverse reaction to the scaffold or its degradation products. A fibrous capsule and three distinct layers were observed, each with its own unique histological characteristics, including presence or absence of vessel structures, and the composition of extracellular matrix. In one case with unknown causality, the scaffold did not integrated with the native tissue. No safety issues related to the scaffold were reported. Conclusions. These data demonstrate the safety and performance of the polyurethane scaffold and illustrate new tissue generation resulting in significant pain reduction and functional improvement

The goal of this prospective, randomized study is the long-term evaluation of clinical, functional and MRI results after implant free press-fit ACL reconstruction performed using the bone-patella-tendon (PT) vs. hamstrings (HT) graft. 62 ACL insufficient patients without any concomitant sports injuries took part in a prospective, randomized study (31 PT, 31 HT). All procedures were conducted by the senior author between 10/98 and 09/99. Both surgical procedures were performed without any implants in press-fit technique with intra-operative x-ray control. At a mean FU time of 8.8 years 53 patients (28 PT, 25 HT) were examined by different scores, KT-1000, one leg hop test, kneeling- and knee-walking-test and isokinetic examination. We also performed bilateral MRI to determine the cartilage defects of both injured and uninjured knee. The results were compared with the intra-operative cartilage status. All MRIs were examined by an independent radiologist. For statistical analysis, the Student’s t-test and the chi. 2. –test was used (p< 0.05). On FU, neither the Tegner nor the Lysholm Score showed any significant results (Tegner 4.86 PT/5.29 HT, Lysholm 87.2/92.47). In the IKDC Score 84% of the PT and 94.4% of the HT group had a normal or nearly normal result (A or B) (p< 0.05), none had a severely abnormal result (D). The KT-1000 stability test and the pivot shift test showed no significance (KT-1000 side-to-side difference of < 3 mm 95.1%/91.7%; pivot glide in 28.0%/17.6%, no cross pivot shift). Isokinetic testing showed nearly normal quadriceps function in both groups (96.0%/96.4%), the hamstring strength was lower in the HT group without reaching statistical significance (100.3%/95.1%). The significant difference of the kneeling- and knee-walking-tests at 1 year FU persisted at year 9 (kneeling: 1.5/1.1; knee-walking: 1.72/1.14 (p< 0.05). Also, the single leg hop test was better in the HT group; however, the results were not significant (95.8%/99.1%). The MRI results showed no difference in cartilage status grade 0–2 using the ICRS-protocol (69.6%/65.0%), the cartilage status of the uninjured knees showed in both groups a similar distribution. Tunnel measurements did not show any widening of the femoral tunnel (−11.3%PT, −0.4%HT). However, the tibial tunnels were clearly widened in both groups (+16.0%/+15.7%). Also, the Caton Index for patellar height (−0.073/−0.085) as well as the sagittal ACL angle (+1.96°/+2.37°), both compared to the uninjured knee, revealed no significant difference. The implant free press-fit technique of ACL reconstruction using PT and HT grafts with anatomic graft placement is an excellent technique to preserve the cartilage and meniscal status without any significant differences between the operated and non-operated knees on FU. A significantly lower morbidity was noted in the HT group

The weight-bearing status of articular cartilage has been shown to affect its biochemical composition. We have investigated the topographical variation of sulphated glycosaminoglycan (GAG) relative to the DNA content of the chondrocyte in human distal femoral articular cartilage.

Paired specimens of distal femoral articular cartilage, from weight-bearing and non-weight-bearing regions, were obtained from 13 patients undergoing above-knee amputation. After papain enzyme digestion, spectrophotometric GAG and fluorometric DNA assays assessed the biochemical composition of the samples. The results were analysed using a paired t-test.

Although there were no significant differences in cell density between the regions, the weight-bearing areas showed a significantly higher concentration of GAG relative to DNA when compared with non-weight-bearing areas (p = 0.02).

We conclude that chondrocytes are sensitive to their mechanical environment, and that local loading conditions influence the metabolism of the cells and hence the biochemical structure of the tissue.

Introduction: The indications for medial unicompartmental knee arthroplasty (UKA) remain controversial; in particular, those relating to the state of the patello-femoral joint (PFJ). Some authorities consider the presence of anterior knee pain (AKP) and/or full thickness cartilage loss (FTCL) to be a contraindication. The aim of this study was to determine the influence of patello-femoral problems on the outcome of medial UKA. Materials and Methods: This prospective study involved one hundred knees with cemented medial Oxford UKA (phase 3), via a minimally invasive approach. Pre-operatively presence or absence of AKP was noted. The cartilage status of medial and lateral patello-femoral joint was grade and recorded intra-operatively. Outcome was evaluated at one-year with the Knee Society Score and the Oxford Knee Score (OKS). Results: 54% of patients had pre-operative AKP. The clinical outcome at one year was not dependent on the presence or absence of pre-operative AKP [OKS: 40.2 (± 8.2) for patients without pre-op. AKP and OKS: 40.8 ((± 6.8) for patients with pre-operative AKP]. 35% of patients had FTCL seen at operation in the PFJ. The outcome at one year was independent of the state of the medial and/or lateral PFJ [OKS = 40.7 (± 7) with normal or partial thickness cartilage loss and OKS = 39.8 (± 7) with full thickness cartilage loss in PFJ]. Conclusions: These short-term results suggest that for the Oxford UKA the presence of anterior knee pain or full thickness cartilage damage in patello-femoral joint should not be considered to be a contraindication