Spontaneous muscle regenerative potential is limited, as severe injuries incompletely recover and result in chronic inflammation. Current therapies are restricted to conservative management, not providing a complete restitutio ad integrum; therefore, alternative therapeutic strategies are welcome, such as cell-based therapies with stem cells or Peripheral Blood Mononuclear Cells (PBMCs). Here, we described two different in vitro myogenic models: a 2D perfused system and a 3D bioengineered scaffold within a perfusion bioreactor. Both models were assembled with human bone marrow-derived mesenchymal stem cells (hBM-MSCs) and human primary skeletal myoblasts (hSkMs) to study induction and maintenance of myogenic phenotype in presence of PBMCs. When hBM-MSCs were cultured with human primary skeletal myoblasts (hSkMs) in medium supplemented with 10 ng/mL of bFGF; cells showed increased expression of myogenic-related gene, such as Desmin and Myosin Heavy Chain II (MYH2) after 21 days, and a prevalent expression of anti-inflammatory cytokines (IL10, 15-fold). Next, PBMCs were added in an upper transwell chamber and hBM-MSCs significantly upregulated myogenic genes throughout the culture period, while pro-inflammatory cytokines (e.g., IL12A) were downregulated. In 3D, hBM-MSCs plus hSkMs embedded in fibrin-based scaffolds, cultured in dynamic conditions, showed that all myogenic-related genes tended to be upregulated in the presence of PBMCs, and Desmin and MYH2 were also detected at protein level, while pro-inflammatory cytokine genes were significantly downregulated in the presence of PBMCs. In conclusion, our works suggest that hBM-MSCs have a versatile myogenic potential, enhanced and modulated by PMBCs. Moreover, our 3D biomimetic approach seemed to better resemble the tissue architecture allowing an efficient in vitro cellular cross-talk.

Poor tendon repair is an unsolved issue in clinical practice, due to complex tendon structure. Tendon stem/progenitor cells (TSPCs) play key roles in homeostasis, regeneration, and inflammation regulation in acute tendon injuries, and rely on TGF-β signaling for recruitment into degenerative tendons. In this study, we aimed to develop an in vitro model for tenogenesis adopting a dynamic culture of a fibrin 3D scaffold, bioengineered with human TSPCs collected from both healthy and tendinopathic surgery explants (Review Board prot./SCCE n.151, 29 October 2020). 3D culture was maintained for 21 days under perfusion provided by a custom-made bioreactor, in a medium supplemented with hTGF-β1 at 20 ng/mL. The data collected suggested that the 3D in vitro model well supported survival of both pathological and healthy cells, and that hTGF-β signaling, coupled to a dynamic environment, promoted differentiation events. However, pathological hTSPCs showed a different expression pattern of tendon-related genes throughout the culture and an impaired balance of pro-inflammatory and anti-inflammatory cytokines, compared to healthy hTSPCs, as indicated by qRT-PCT and immunofluorescence analyses. Additionally, the expression of both tenogenic and cytokine genes in hTSPCs was influenced by hTGF-β1, indicating that the environment assembled was suitable for studying tendon stem cells differentiation. The study offers insights into the use of 3D cultures of hTSPCs as an in vitro model for investigating their behavior during tenogenic events and opens perspectives for following the potential impact on resident stem cells during regeneration and healing events.

Tendon injuries are a common problem that can significantly impact an individual's quality of life. While traditional surgical methods have been used to address this issue, Extracellular Vesicles (EVs) have emerged as a promising approach to promote tendon repair and regeneration mechanisms, as they deliver specific biological signals to neighbouring cells. In this study, we extracted human Tendon Progenitor Stem cells (hTPSCs) from surgery explants and isolated their EVs from perfused and static media.

hTPSCs were isolated from tendon surgery biopsy (Review Board prot./SCCE n.151, 29/10/2020) and cultured in both static and dynamic conditions, using a perfusion bioreactor (1ml/min). When cells reached 80% confluence, they were switched into a serum-free medium for 24 hours for EVs-production. Conditioned media was ultra-centrifuged for 90min (100000g). The recovered pellet was then characterized by size and concentration (Nanosight NS300), Zeta potential (Mastersizer S), morphology (SEM and TEM) and protein quantification.

hTPSCs stemness and multipotency were confirmed through CD73, CD90, and CD105 expression and confirmation of quad-lineage (adipo-osteo-chondro-teno) differentiation. After 7 days, hTPSCs were ready for EVs-production. Ultracentrifugation revealed the presence of particles with a concentration of 7×107 particles/mL consistent across both cultures. Further characterization indicated that EVs collected from perfused conditions displayed an elevated vesicle mean size (mean 143±6.5 nm) in comparison to static conditions (mean 112±7.4 nm). Consistent with, but not in proportion with, the above protein content was measured at 20 ng/ml (dynamic) and 7 ng/mL (static) indicating a nearly 3-fold increase in concentration associated with a ~22% increase in particle size.

Proposed data showed that sub-200 diameter vesicles were successfully collected from multipotent hTPSCs starvation, and the vesicle size and protein concentration were compatible with established EV literature; furthermore, dynamic culture conditions seemed more suitable for EVs-production. Further characterization will be required to better understand, EVs-compositions and their role in tendon regenerative events.

Abstract

Introduction

An additional pathology should be considered for Achillodynia differentials – the intratendinous tear (ITT) – for which we describe symptoms, ultrasound findings and co-presenting pathology.

Introduction

Achilles tendinopathy (AT) is a highly prevalent injury in athletes and non-athletes with an unknown aetiology. Genetic risk factors have been a recent focus of investigation. The aim of this systematic review was to determine which loci have been linked with mid-portion AT and could potentially be used as biomarkers in tendinopathy risk models or as preventative or therapeutic targets.

Introduction

Rotator cuff healing after an arthroscopic repair is discussible because of the high incidence of failures. Among biologic augmentations currently used, platelet-rich plasma (PRP) is one of the most applied, supposed to enhance and accelerate the healing process in different musculoskeletal disorders. However, the evidence supporting its successful administration is still lacking, especially in the field of the rotator cuff repair. Our purpose is to clarify if the recovery is accelerated and the integrity of repaired construct is increased in patients undergoing PRP injections after arthroscopic repair of the rotator cuff.

Introduction

recent studies recognised metabolic abnormalities as additional factors in the development of rotator cuff (RC) tendinopathy. It has been hypothesised that the insertional area of this tendon is susceptible to degenerative changes due to intrinsic hypovascularization. The mechanisms underlying this process are not yet clear. In this study we attempted to confirm if larger lesions of the RC are related to impaired vasodilatatory response of the local circulation in conditions of “hemodynamic stress”.

Introduction

Ostochondral lesion of the knee is a common cause of chronic knee pain. Arthroscopic treatment with subcondral microfracture is a widespread technique leading to noticeable improvement of knee function and pain. To improve the effectiveness of this treatment options, we thought to add intra (PRF) or post-operative (PRP) growth factors. Platelet rich plasma (PRP) is obtained by centrifugation of the blood to produce a plasma with high concentration of platelets and growth factors. This latter represents a promising method to manage degenerative cartilage lesion and can be used postoperatively to improve clinical results of patients treated arthroscopically. Platelet Rich Fibrin (PRF) has been presented as a second-generation platelet concentrate, and it is used intraoperatively to cover the microfracuteres’ holes. No literature was found about using of PRF intraoperative in association with arthroscopic microfracture technique. The aim of this study is to compare clinical outcomes of the treatment of knee osteochondral lesion using arthroscopic microfracture technique alone or in association with PRF Intraoperative application using “Vivostat” system or with PRP “ReGen Lab” postoperative injection.

To describe the prevalence and incidence of Methicillin-resistant Staphylococcus aureus (MRSA) colonisation during the patient journey for patients admitted to orthopaedic and trauma wards, we carried out a prospective audit at the University Hospital of North Staffordshire NHS Trust, England.

The Study Population comprised patients admitted to the trauma and elective orthopaedic wards, with an expected stay of 48 hours or more between March and May 2003.

Patients were swabbed for MRSA colonisation on ward admission, transfer to another ward and discharge from hospital. Elective patients undergoing major joint surgery were also swabbed at a pre-operative assessment clinic. Colonised patients were treated depending on individual risk assessment.

Five hundred and fifty-nine eligible patients were admitted to hospital. Of these, 323 (101 elective, 192 trauma and 30 non-orthopaedic) patients were included in the study, of whom 28 elective patients (28%), 43 trauma patients (22%), and seven non-orthopaedic patients (23%) were colonised with MRSA at any time during the audit period. Of the 80 patients identified as negative for MRSA colonisation at pre-assessment screening and included in the audit, ten (9.5%) were found to be colonised on admission.

There is a high prevalence of MRSA colonisation in patients admitted to the orthopaedic and trauma wards in our setting. A policy of pre-admission screening, though able to identify MRSA carriage does not guarantee that patients are not colonised in the period between screening and admission. Consideration should be given to screening all patients for MRSA who are admitted to an orthopaedic ward.

Introduction

Fifty thousand knee replacements are performed annually in the UK at an estimated cost of £150 million. However, there is uncertainty as to the best surgical approach to the knee joint for knee arthroplasty. We undertook a randomised controlled trial to compare a standard medial parapatellar arthrotomy with sub-vastus arthrotomy for patients undergoing primary total knee arthroplasty in terms of short and long term knee function.

Introduction

This study was to investigate the association of developmental dysplasia of the hip (DDH) and primary protrusion acetabuli (PPA) with Vitamin D receptor polymorphisms TaqI and FokI and oestrogen receptor polymorphisms Pvu II and XbaI.

To evaluate the effects of eccentric strengthening exercises (ESE) in athletic patients with Achilles tendinopathy. Forty five athletic patients (29 men, average age 26 years; 16 women, average age 28 years; average height: 173 ± 16.8, range 158 to 191; average weight 70.8 kg ± 15.3, range 51.4 to 100.5) with clinical diagnosis of unilateral tendinopathy of the main body of the Achilles tendon completed the VISA-A questionnaire at first attendance and at their subsequent visits. The patients underwent a graded progressive eccentric calf strengthening exercises programme for 12 weeks.

The mean pre-management VISA-A scores of 36 (SD 23.8; 95% C.I.: 29 – 46) improved to 52 (SD 27.5; 95% C.I.: 41.3 – 59.8) at the latest follow up (p = 0.001). Twenty seven of the 45 patients responded to the eccentric exercises. Of the 18 patients who did not improve with eccentric exercises, 5 (mean age: 33 years) improved with two peritendinous aprotinin and local anaesthetic injections. 10 of the 18 patients (9 men, mean age 35 years; 1 woman aged 40 years) who did not improve with eccentric exercises and aprotinin injections proceeded to have surgery. The remaining three patients (3 women, mean age 59.6 years; 2 men, mean age 63 years) of the 18 non-responders to eccentric exercises and aprotinin injections declined surgical intervention.

ESE in athletic patients provide comparable clinical outcome compared to our previous results in non-athletic patients. ESE are a viable option for the management of AT in athletes, but, in our hands, only around 60% of our athletic patients benefited from an intensive, heavy load eccentric heel drop exercise regimen alone. If ESE fail to improve the symptoms, aprotinin and local anaesthetic injections should be considered. Surgery is indicated in recalcitrant cases after 3 to 6 months of non operative management.

Repair of chronic Achilles tendon rupture is technically complex. Flexor jallucis longus (FHL) and peroneus brevis (PB) tendon transfers have been described, but the mechanical properties of these tissues have not been well reported.

The FHL, PB and tendo achilles (TA) tendons were harvested from 17 fresh frozen human cadavers free of gross pathology (mean age 69 years). Samples were tested in uniaxial tension at 100% per minute. Samples were secured using special jigs for the bony aspect or by freezing the tendons in cryogrips using liquid carbon dioxide. The peak load (N), linear stiffness (N/mm) and energy to peak load (N*mm) were determined. Mechanical data was analysed using one way analysis of variance (ANOVA) followed by a Games Howell multiple comparison post-hoc test.

Fifty one tendons were harvested and mechanical testing was successfully completed in all samples apart from one PB that slipped from the grips during testing (sample was omitted from the analysis). The mean ultimate loads differed for each group, with the TA tendons being the strongest (1724.5 N ± 514.3) followed by FHL (511.0 N ± 164.3) and PB (333.1 N ± 137.2) (P< 0.05). Similar results were found with respect to energy, with TA tendons absorbing the most energy followed by FHL and PB (P< 0.05). Stiffness for the TA tendons (175.5 N/mm ± 94.8) was greater than FHL (43.3 N/mm ± 14.1) and PB (43.6 N/mm ± 18.9), which did not differ from each other.

FHL is stronger than PB, but have similar stiffness. The mechanical properties of PB and FHL were both inferior to TA. Graft stiffness appears to be an important variable rather than ultimate load based on the clinical success of both techniques.

Our objective was to determine the plasma levels of substance P (SP) in patients with postoperative stiffness after arthroscopic rotator cuff repair.

Plasma samples were obtained at 15 months from surgery from 2 groups of patients who underwent arthroscopic repair of a rotator cuff tear. In Group 1, 30 subjects (14 men and 16 women, mean age: 64.6 years, range 47 to 78) with shoulder stiffness 15 months after arthroscopic rotator cuff repair were recruited. In Group 2, 30 patients (11 men and 19 women, mean age: 57.8 years, range 45 to 77) were evaluated 15 months after successful arthroscopic rotator cuff repair. Immunoassays were performed with commercially available assay kits to detect the plasma levels of SP.

The mean plasma levels of SP in patients with postoperative stiffness were significantly greater than those in the control group (81.06 ± 27.76 versus 23.49 ± 5.64, P < 0.05).

The plasma concentrations of substance P in patients with shoulder stiffness after arthroscopic rotator cuff repair are higher compared to plasma levels of SP in patients with a good postoperative outcome. The neuronal upregulation of SP shown in the plasma of patients with post operative shoulder stiffness may underlay not only the symptoms of adhesive capsulitis, but also its development.

Both acute and chronic hamstring injuries are disabling injuries, and occur almost entirely to elite athletes. We report our experience in the management of injuries of this location. Twenty seven patients (29 injuries) were included in the present study. They completed a questionnaire detailing their pre-injury activity, injury mechanism, rehabilitation and a subjective assessment of their recovery. At clinical examination pain and hip motion were evaluated.

Hamstring injuries predominantly affect males on the left side. Most procedures carried out were explorations with limited debridement and suture of the tendon. One third of patients felt they had returned to 100% of their pre-injury level, and 33% felt they had returned to 80–90% of their pre-injury level, the rest varied between < 20–80%. 45% gave a value of zero on the visual analogue pain scale independent of activity, those who gave a value above this had pain during active sports but not at rest.

Early repair leads to a much better recovery of muscle function, especially when dealing with complete avulsions. Lesions to the origin of the hamstring can be successfully managed if a high suspicion for the condition exerted.

Arthroscopic management has been recommended for some SLAP lesions, but no studies have focused on patients over 50 with rotator cuff tear and Type II SLAP lesion. Our hypothesis was that there was no difference in clinical outcome between repairing of the Type II SLAP lesion and tenotomy of the long head of the biceps tendon after having repaired the rotator cuff tear. This was a randomized controlled clinical trial.

We recruited 63 patients. In 31 patients, we repaired the rotator cuff and the Type II SLAP lesion (Group 1). In the other 32 patients, we repaired the rotator cuff and tenomized the long head of the biceps (Group 2). 7 patients (2 in the group 1 and 5 in the group 2) were lost to final follow up.

At the 5.2 year follow-up, statistically significant differences were seen with respect to the UCLA score and ROM values. In Group 1 (SLAP repair and rotator cuff repair), the UCLA showed a statistically significant improvement from a pre-operative average rating of 10.4 (range 6 to 14) to an average of 27.9 (24–35) postoperatively (P< 0.001). In Group 2 (biceps tenotomy and rotator cuff repair) the UCLA showed a statistically significant improvement from a pre-operative average rating of 10.1 (range 5 to 14) to an average of 32.1 (range 30 to 35) post-operatively (P< 0.001) There was statistically significant difference in total post-operative UCLA scores and ROM when comparing the two groups post-operatively (P< 0.05).

There are no advantages in repairing a Type II SLAP lesion when associated with a rotator cuff tear in patients over 50. Rotator cuff repair alone is sufficient to produce a good post-operative outcome, allowing to avoid post-operative stiffness of the shoulder.

Antibiotic-associated Clostridium difficile diarrhoea may complicate surgery for proximal femoral fracture. We undertook a 4 year case control study to evaluate the effects of a change in antibiotic prophylaxis in our department.

In the period January 2003 to January 2005, patients received three doses of cefuroxime (1.5 g). The new regimen is a single dose of cefuroxime (1.5 g) with gentamicin (240 mg) at induction. Prior to the change in prophylaxis, 912 patients underwent surgery for neck of femur fracture. Following the change, 899 patients underwent surgery over the period March 2005 to March 2007. 38 patients developed C. difficile infection (4.2%) in the initial group, compared with 14 patients (1.6%) in the group following the change in prophylaxis (P=0.009). Patients with C difficile infection also had a statistically significant increase in antibiotic exposure, inpatient stay, morbidity and inpatient mortality.

The main challenges regarding antibiotic selection are failure of prophylaxis, often because of infection with MRSA, and C. difficile-associated diarrhoea as a consequence of antibiotic prophylaxis. Infection with C. difficile is reduced with the new regimen. We advocate the use of the new regimen as an effective alternative to multiple dose cephalosporins for the prevention of C. difficile infection in this group of high risk patients.

The Achilles tendon is commonly operated on, but has associated wound complications, ranging from 7–14% in previously reported series larger than 100 cases. We report a retrospective review of one surgeon’s practice conducted to assess the prevalence of wound complications associated with acute and chronic rupture repair, peritenolysis, tenodesis, debridement, retrocalcaneal exostectomy/bursectomy, and management of calcific tendinopathy of the Achilles tendon. The study evaluated the incidence of infection, and other wound complications such as suture reactions, scar revision, hematoma, incisional neuromas and granuloma formation.

A total of 219 surgical cases were available for review (140 males, 70 females; average age at the time of surgery: 46.5 ± 12.6 years, range 16–75). Seven patients experienced a wound infection, three had keloid formation, six had suture granulomas, and six had suture abscesses, with an overall complication rate of 22 of 219 surgeries (10.1%). There were no hematomas. Seven patients had additional surgery following their wound complications; some had simple granuloma excision, while one necessitated a flap. Patients with risk factors such as diabetes, smoking and Rheumatoid arthritis necessitating steroids were more likely to have a wound complication, (Fisher’s Exact Test, P=.03).

Complications with Achilles tendon surgery may be unavoidable. Suture granulomas may appear in a delayed fashion. Absorbable and non-absorbable suture can be implicated.

Orthopaedic surgeons vary in their surgical approaches to total knee arthroplasty. The aim of this investigation was to compare outcomes after two different surgical approaches. The study was a prospective single-centre longitudinal randomized controlled trial. A sub-vastus approach was compared with a medial para-patellar approach. Participating surgeons elected to randomize their patients to one of the two types of approach. Outcomes included the Knee Society (KS) Clinical Rating System, WOMAC Osteoarthritis Index, SF-36, and EuroQol (measured at 1, 6, 12 and 52 weeks post-operatively compared to baseline) complications, surgeon rated ease of exposure, and proportion of patients who had a lateral release.

Two hundred and thirty one patients were randomized to the two approaches. One hundred and sixteen patients were randomized to the sub-vastus approach. At one week compared to baseline, range of motion, KS global, KS knee, and KS pain scores were significantly better in the sub-vastus group. At six weeks, the medial para-patellar group tended to have better outcomes, but not statistically significantly. At fifty-two weeks compared to baseline, the WOMAC global and pain scores, the SF36 physical function and role-physical scores, and the EuroQol utility and pain score were significantly better in the sub-vastus group. Surgeons reported the ease of exposure in the sub-vastus group was significantly worse on average.

This trial is the largest of its kind to date, and the first, so far as we are aware, to compare clinical outcomes of different surgical approaches at one year post-operatively. The sub-vastus approach to total knee arthroplasty was more effective than a medial para-patellar approach at both one week and fifty-two weeks post-operatively in patients whose surgeons considered either approach would be suitable. However, surgeons reported worse ease of exposure in the sub-vastus group.