Introduction/Aim. Flexor tendon injuries of the hand are common with an incidence of over 3000 per annum in the UK. These injuries can affect hand function significantly. Early treatment with optimal repair is crucial to prevent disability. This study aimed at investigating the re-rupture rate following primary flexor tendon repair at our institution and to identify potential risk factors for re-rupture. Methods. 100 flexor tendons' injuries that underwent primary repair over a one-year period were reviewed retrospectively. Data was collected on age, gender, occupation, co morbidities, injured fingers, hand dominance, smoking status, zone of injury, time to surgery, surgeon grade, type of repair and suture, and antibiotic use on included patients. Causes of re-rupture were examined. We compared primary tendon repairs that had a re-rupture to those that did not re-rupture. Univariate and multivariate analysis was undertaken to identify the most significant risk factors for re-rupture. Results. 11 out of 100 (11%) repaired tendons went on to re-rupture. A significantly higher proportion of tendons re-rupture was noted when the repair was performed on the dominant hand (p-value = 0.009), in Zone 2 (0.001), and when a surgical delay of more than 72 hours from the time of injury occurred (0.01). Multivariate regression analysis identified repairs in Zone 2 to be the most significant predictor of re-rupture. Causes of re-rupture included infection in 5, rupture during rehabilitation exercises in 5 and fall in 1 patient. Conclusions. A re-rupture rate of 11% was noted in our study. Patients with Zone 2 injuries, repair on dominant hand and those with a surgical delay of more than 3 days were at higher risk of re-rupture. Careful consideration of these factors especially zone 2 injuries is crucial to reduce this rate. Providing a fast-track pathway for managing these patients can reduce time to surgery

Autologous cell therapy using stem cells and progenitor cells is considered to be a popular approach in regenerative medicine for the repair and regeneration of tissue and organs. In orthopaedic practice, autologous cell therapy has become a major focus, particularly, as a feasible treatment for tendon injury.

Tendons are dense connective tissue that bridge bone to muscle and transmit forces between muscle and bone to maintain mechanical movement. Tendons are poorly vascularised and have very little capacity to self-regenerate. Degeneration of tendon is often caused by injury. The pathogenesis of tendon injury, commonly known as tendinosis, is not an inflammatory condition but is secondary to degenerative changes, including disruption of the collagen matrix, calcification, vascularisation and adipogenesis. The aetiology of tendinosis is considered to be multifactorial and the pathogenesis is still unclear. Intrinsic factors such as a lack of blood and nutrition supply and extrinsic factors such as acute trauma and overuse injury caused by repetitive strain, have been implicated as contributors to the pathogenesis of tendinosis. More recent studies suggest that programmed tendon cell death (tenocyte apoptosis) may play a major role in the development of tendinosis. Such cellular abnormalities may influence the capacity of tendon to maintain its integrity.

Traditional treatments such as anti-inflammatory drugs, steroid injections and physiotherapy are aimed at symptom relief and do not address the underlying pathological changes of degeneration. Here, we propose that autologous cell therapy may be an innovative and promising treatment for tendon injury. We will present evidence that suggest that autologous tendon cell therapy may be feasible to repair and regenerate tendon.

We will also present data summarising the preclinical evaluation of autologous tendon cell therapy in animal models and the safety and tolerability of autologous tendon cell therapy in humans in studies, which are currently conducted at the Centre for Orthopaedic Research at the University of Western Australia.

Introduction

Massive rotator cuff repairs have up to 60% failure rate and repair of a chronic repair can have up to 40% failure rate. With this in mind, new methodologies are being to being developed to overcome this problem. The use of tendon augmentation grafts is one of them. Prior attempts have shown equivocal or poorer outcomes to control repairs. Aims and objectives: The specific aim of these expereiments was to test how well ovine tendon cells would take to a specific biological augmentation graft (Ligamimetic), and wheter tissue engineering techniques would enhance this.

Our aim was to compare the biomechanical strength modified side-to-side repair with modified pulvertaft technique keeping overlap length, anchor points, type of suture, suture throw and amount of suture similar.

In our study, we have used turkey tendons. Two investigators performed 34 repairs during one summer month. All mechanical testing was carried out using the tensile load testing machine. Variables measured were maximum load, load to first failure, modulus, load at break, mode of failure, site of failure, tensile strain, and tensile stress. The statistical comparison was carried by Levene's test and T test for means.

The mean maximum load tolerated by modified side-to-side repair was 50.3N(S.D13.7) and that by modified pulvertaft 46.96N(S.D: 16.4), overall it was 48.29 N (S.D: 14.57). The tensile stress at maximum load for modified pulvertaft and modified side-to-side repair was 4.2MPa(S.D: 3.1) and 4.7 MPa (S.D: 3.8) respectively {Overall 4.3MPa(S.D: 3.5)}. The tensile stress at yield was 4.01 MPa (S.D: 3.1) and 5.5 MPa (S.D: 3.7) respectively for modified pulvertaft and modified side-to-side repair {overall 4.44 MPa (S.D: 3.45)}. The tensile strain at maximum load respectively for side-to-side and modified pulvertaft repair was 7.87%(S.D: 33.3) and 7.84%(S.D: 34.02) respectively.

We found no statistical difference between 2 repairs in terms of strength, load to first failure, and maximum load to failure. The suture cut through was the commonest mode of failure.

Our study uniquely compares two techniques under standard conditions, and contrary to existing evidence found no difference.

Currently, the consensus regarding subscapularis tendon repair during a reverse total shoulder arthroplasty (rTSA) is to do so if it is possible. Repair is thought to decrease the risk of dislocation and improve internal rotation but may also increase stiffness and improvement in internal rotation may be of subclinical benefit. Aim is to retrospectively evaluate the outcomes of rTSA, with or without a subscapularis tendon repair. We completed a retrospective review of 51 participants (25 without and 26 with subscapularis repair) who received rTSR by a single-surgeon using a single-implant. Three patient reported outcome measures (PROM) were assessed pre-operatively and post-operative at twelve months, as well as range of movement (ROM) and plain radiographs. Statistical analysis utilized unpaired t tests for parametric variables and Mann-Whitney U test for nonparametric variables. External Rotation ROM pre-operatively was the only variable with a significance difference (p=0.02) with the subscapularis tendon repaired group having a greater range. Pre- and post-operative abduction (p=0.72 & 0.58), forward flexion (p=0.67 & 0.34), ASES (p=0.0.06 & 0.78), Oxford (p=0.0.27 & 0.73) and post-operative external rotation (p=0.17). Greater external rotation ROM pre-operatively may be indicative of the ability to repair the subscapularis tendon intra-operatively. However, repair does not seem to improve clinical outcome at 12 months. There was no difference of the PROMs and AROMs between the subscapularis repaired and not repaired groups for any of the variables at the pre-operative or 12 month post operative with the exception of the external rotation ROM pre-operatively. We can conclude that from PROM or AROM perspective there is no difference if the tendon is repaired or not in a rTSR and indeed the patients without the repair may have improved outcomes at 12 months

Purpose. The posterolateral or posterior approach for total hip arthroplasty has the advantages of preserving the hip abductor musculature and providing good visualization during femoral preparation and component insertion. Although posterolateral approach is one of the popular approaches in hip arthroplasty, it has been reported high dislocation rate as a drawback. To compensate the drawback the repair of short external rotator of hip is thought to be important. Therefore, we investigated incidence of failed repaired short external rotator muscles, dislocation rate and time of failure between tendon to tendon and tendon to bone repair technique through prospective study more than 1 year follow up. Materials and methods. We performed 213 hip arthroplasties in 202 patients from May 2012 to January 2015. After exclusion of 15 hips due to follow-up loss(9 hips), death(2 hips), greater trochanteric fragment displacement(3 hips) and severe contracted short external rotator(1 hip), we investigated 198 hips in 187 patients. 57 patients were male and 130 patients were female. The mean age of patient was 70.4 (32–98) years. Reattachment short external rotator with posterior capsule to postero-superior aspect of greater trochanter(tendon to bone group, 111 hips) or to the tendon(tendon to tendon group, 87 hips) was performed. Two No.26 metal wire markers were fixed at the greater trochanter tip and short external rotator tendon respectively with a distance less than 1.2cm, and the distance between two wire markers was observed at postoperative 1 day, 2 weeks, 3 months, and annually radiographs in neutral position. When the distance was more than 2.5cm or one of the wire markers was invisible, we defined them the failure of short external rotator repair. The mean follow up period was 28.8 (12–45) months. Results. Failure rate of tendon to bone repair technique(17.1%) was significantly less as compared to that of tendon to tendon repair technique(70.1%)(p<0.001). The failure of short external rotator repair happened mostly within postoperative 2 weeks, which was 89.5% in tendon to bone(p=0.025) and 93.4% in tendon to tendon repair (p<0.001). Dislocation was observed in 2 (1.8%) hips in tendon to bone repair group and in 7 (8.0%) hips in tendon to tendon repair group respectively, which was significantly higher dislocation rate in tendon to tendon repair group. A significant correlation was also observed between failure of short external rotator repair and dislocation (p=0.032). Conclusions. Tendon to bone repair technique is superior to tendon to tendon technique in terms of failure rate of short external rotator repair in hip arthroplasty. Tendon to bone repair of short external rotator with posterior capsule was beneficial to reduce dislocation rate as compared with tendon to tendon repair technique. As majority of failure of short external rotator happened within postoperative 2 weeks, restriction of internal rotation should be recommended through the period

The extracortical single-button (SB) inlay repair is one of the most preferred distal biceps tendon repair techniques. However, specific complications such as neurovascular injury and non-anatomic repairs have led to the development of techniques that utilize intracortical double-button (DB) fixation. To compare the biomechanical stability of the extracortical SB repair with the anatomical DB repair technique. Controlled laboratory study. The distal biceps tendon was transected in 18 cadaveric elbows from 9 donors. One elbow of each donor was randomly assigned to the extracortical SBor anatomical DB group. Both groups were cyclically loaded with 60N over 1000 cycles between 90° of flexion and full extension. The elbow was then fixed in 90° of flexion and the repair construct loaded to failure. Gap-formation and construct stiffness during cyclic loading, and ultimate load to failure was analysed. After 1000 cycles, the anatomical DB technique compared with the extracortical SB technique showed significantly less gap-formation (mean difference 1.2 mm; p=0.017) and significantly more construct stiffness (mean difference 31 N/mm; p=0.023). Ultimate load to failure was not significantly different comparing both groups (SB, 277 N ±92 vs. DB, 285 N ±135; p=0.859). The failure mode in the anatomical DB group was significantly different compared with the extracortical SB technique (p=0.002) and was due to fracture avulsion of the BicepsButton in 7 out of 9 specimens (vs. none in SB group). Our study shows that the intracortical DB technique produces equivalent or superior biomechanical performance to the SB technique. The DB repair technique reduces the risk of nerve injury and better restores the anatomical footprint of biceps tendon. The DB technique may offer a clinically viable alternative to the SB repair technique

Normal digital flexion relies on flexor tendon pulleys to transmit linear muscular force to angular digital motion. Despite the critical role these pulleys play, there is a growing trend among surgeons to partially sacrifice or “vent” them during flexor tendon repair to improve surgical exposure. Although this new practice is reported to improve outcomes after flexor tendon repair, there is concern for the long-term effects of bowstringing, reduced finger range of motion (ROM) and altered tendon biomechanics. The objective of this study was to examine the effects of the application of a thermoplastic ring, acting as an “external” pulley, on flexor tendon biomechanics and finger ROM. We hypothesized that the application of an external thermoplastic ring would produce a centripetal force over the tendon to reduce bowstringing, improve finger ROM, and restore tendon loads following pulley venting. Twelve digits comprised of the index, long, and ring fingers from four cadaveric specimens were tested using a novel in-vitro active finger motion simulator. Servo-motors were used to generate motion. Loads induced by flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP), and joint range of motion were measured with each sequential sectioning of the A2, A3, and A4 flexor pulley, in comparison to a native healthy finger condition. At each finger condition, A2 and A4 external thermoplastic pulley rings were applied over the proximal phalanx and middle phalanx, respectively, to recreate A2 and A4 function. Results were recorded and analyzed using a one way repeated-measures ANOVA. Following venting of the A2, A3 and A4 pulley, proximal interphalangeal joint (PIPJ) ROM significantly decreased by 17.02 ± 8.42 degrees and distal interphalangeal joint (DIPJ) range of motion decreased by 17.25 ± 8.68 degrees compared to intact pulleys. Application of the external rings restored range of motion to within 8.14 ± 8.17 degrees at the PIPJ and to within 7.72 ± 8.95 degrees at the DIPJ. Similarly, pulley venting resulted in a 36% reduction in FDS load and 50% in FDP load compared to intact pulleys. Following application of the external rings, loads were almost restored to normal at 7% reduction for FDS load and 13% reduction for FDP load. Venting of flexor tendon pulleys significantly alters flexor tendon biomechanics and digit range of motion. The application of thermoplastic rings acting as external pulleys over the proximal and middle phalanges is an effective, inexpensive, non-invasive and reproducible therapeutic method to restore flexor tendon biomechanics and digit range of motion

No animal model currently exists for hip abductor tendon tears. We aimed to 1. Develop a large animal model of delayed abductor tendon repair and 2. To compare the results of acute and delayed tendon repair using this model. Fourteen adult Romney ewes underwent detachment of gluteus medius tendon using diathermy. The detached tendons were protected using silicone tubing. Relook was performed at six and 16 weeks following detachment, histological analysis of the muscle and tendon were performed. We then attempted repair of the tendon in six animals in the six weeks group and compared the results to four acute repairs (tendon detachment and repair performed at the same time). At 12 weeks, all animals were culled and the tendon–bone block taken for histological and mechanical analysis. Histology grading using the modified Movin score confirmed similar tendon degenerative changes at both six and 16 weeks following detachment. Biomechanical testing demonstrated inferior mechanical properties in both the 6 and 16 weeks groups compared to healthy controls. At 12 weeks post repair, the acute repair group had a lower Movin's score (6.9 vs 9.4, p=0.064), and better muscle coverage (79.4% of normal vs 59.8%). On mechanical testing, the acute group had a significantly improved Young's Modulus compared to the delayed repair model (57.5MPa vs 39.4MPa, p=0.032). A six week delay between detachment and repair is sufficient to produce significant degenerative changes in the gluteus medius tendon. There are significant histological and mechanical differences in the acute and delayed repair groups at 12 weeks post op, suggesting that a delayed repair model should be used to study the clinical problem

Introduction. Successful tendon repairs are reliant on the suture material having high tensile strength, no or little tissue response, good handling characteristics and little elastic/plastic deformation. Plastic deformation contributes to gap formation at a tendon repair site. Previous research has shown a gap greater than 4mm is likely to fail. Pre-tensioning is a commonly used method to improve the handling properties of sutures. This study investigates whether the plastic deformation demonstrated by two suture materials used in flexor tendon repair is affected by manual pre-tensioning. Material/Methods. Twenty lengths of 3/0 Prolene (Ethicon, UK) and 3/0 Ethibond Excel (Ethicon, UK) were selected. Half of the sutures in each group were manually pre-tensioned (longitudinal stretch of 15N for 3s) prior to knot tying (standard surgical knot with six throws) and half were knotted without pre-tensioning. The suture lengths were measured before and after a standardised cyclical loading regime on a tensile tester. The regime was designed to represent the finger flexion forces produced in an active rehabilitation programme after tendon repair. All sutures were subsequently tested to their ultimate tensile strength. Results. After cyclical loading the Prolene sutures not pre-tensioned showed a mean increase in suture length of 5.4% (range 3.3-7%). The pre-tensioned Prolene sutures demonstrated a mean increase of 0.7% (range 0.1-1.9%). This equates to 87% less plastic deformation (p < 0.05 Students' T-test) with pre-tensioning. There were no differences with Ethibond. Pre-tensioning had no effect on ultimate tensile strength for either group. Conclusion. Manual pre-tensioning reduces plastic deformation in Prolene 3/0 sutures without affecting the ultimate tensile strength. This simple technique could theoretically diminish gap formation at the site of a tendon repair

Cadaveric specimens that have been fresh-frozen and then thawed for use have historically been considered to be the gold standard for biomechanical studies and the closest surrogate to living tissue. However, there are notable issues related to specimen rapid decay in the thawed state as well as infectious hazard to those handling the specimens. Cadaveric specimen preparation using a new phenol-based soft-embalmed method has shown considerable promise in preserving tissue in a prolonged fresh-like state while mitigating the infection risk. In this study, we evaluated the ability of soft-embalmed specimens to replace fresh-frozen specimens in the biomechanical study of flexor tendon repair. An ex-vivo study was conducted on six cadaveric hands in both a fresh-frozen, thawed state and following embalming with a phenol-based solution. Six different combinations of flexor digitorum profundus (FDP) tendons, from D2 to D5, and flexor pollicis longus (FPL) tendons were used to create two groups of similar composition with 15 tendons each, one group to be tested fresh and the other following embalming. A 5cm length of each flexor tendon was harvested from zone 2 and transversely cut at the mid-section. A modified-Kessler repair was performed on each specimen using 4–0 Fiberwire, with two core sutures and 1cm purchase on each end. Incisions were closed with a running stitch to prepare the specimen for embalming. The same protocol was used to repair and harvest the second group of tendons one month following the perfusion of a phenol-based solution through the vasculature of the hand and forearm. Tendon repair biomechanics were characterised through a ramp loading to failure (rate 1mm/sec), incorporating the 12 mm travel distance of the testing machine. A video-extensometry technique was used to validate machine recordings for the repair site for force at the 2mm gap distance, the ultimate strength, and the mode of failure. Characteristics of the two groups were tested for equivalency using inferential confidence intervals (ICI). Both fresh and embalmed groups were indistinguishable in both force at 2mm gap (fresh 17.9±4.7N; embalmed 18.1±5.1) and ultimate strength (fresh 43.93±10.0; embalmed 43.7±9.4). With the exception of one specimen with complete suture pull-out, all specimens exhibited partial pull-out as the final mode of failure. Our study demonstrated that tendon repair characteristics of phenol-embalmed specimens were equivalent to fresh specimens. Post-mortem chemical preservation can indeed preserve both visual and biomechanical characteristics of soft tissues. This study opens new avenues in support of the use of embalmed specimens in medical curricula and surgical training

Avulsion of the proximal hamstring tendon from the ischial tuberosity is an uncommon but significant injury. Recent literature has highlighted that functional results are superior with surgical repair over non-surgical treatment. Limited data exists regarding the optimal rehabilitation regime in post-operative patients. The aim of this study was to investigate the early interim patient outcomes following repair of proximal hamstring tendon avulsions between a traditionally conservative versus an accelerated rehabilitation regimen. In this prospective randomised controlled trial (RCT) 50 patients underwent proximal hamstring tendon avulsion repair, and were randomised to either a braced, partial weight-bearing (PWB) rehabilitation regime (CR = 25) or an accelerated, unbraced, immediate full weight-bearing (FWB) regime (AR group; n = 25). Patients were evaluated preoperatively and at 3 months after surgery, using the Lower Extremity Functional Scale (LEFS), Perth Hamstring Assessment Tool (PHAT), visual analog pain scale (VASP), Tegner score, and 12-item Short Survey Form (SF-12). Patients also filled in a diary questioning postoperative pain at rest from Day 2, until week 6 after surgery. Primary analysis was by per protocol and based on linear mixed models. Both groups, with respect to patient and characteristics were matched at baseline. Over three months, five complications were reported (AR = 3, CR = 2). At 3 months post-surgery, significant improvements (p<0.001) were observed in both groups for all outcomes except the SF-12 MCS (P = 0.623) and the Tegner (P = 0.119). There were no significant between-group differences from baseline to 3 months for any outcomes, except for the SF-12 PCS, which showed significant effects favouring the AR regime (effect size [ES], 0.76; 95% CI, 1.2-13.2; P = .02). Early outcomes in an accelerated rehabilitation regimen following surgical repair of proximal hamstring tendon avulsions, was comparable to a traditionally conservative rehabilitation pathway, and resulted in better physical health-related quality of life scores at 3 months post-surgery. Further long term follow up and functional assessment planned as part of this study

Rupture of the pectoralis major (PM) tendon is a rare yet severe injury. Several techniques have been described for PM fixation including a transosseus technique, when cortical buttons are placed at the superior, middle and inferior PM tendon insertion positions. The concern with this technique is the risk that bicortical drilling poses to the axillary nerve as it courses posteriorly to the humerus. This cadaveric study investigates the proximity of the posterior branch of the axillary nerve to the drill positions for transosseus PM tendon repair. Drills were placed through the humerus at the superior, middle and inferior insertions of the PM tendon and the distance between these positions and the axillary nerve, which had previously been marked, was measured using computed tomography (CT) imaging. This investigation demonstrates that the superior border of PM tendon insertion is the fixation position that poses the highest risk of damage to the axillary nerve. Caution should be used when performing bicortical drilling during cortical button PM tendon repair, especially when drilling at the superior border of the PM insertion. We describe ‘safe’ and ‘danger’ zones for transosseus drilling of the humerus reflecting the risk posed to the axillary nerve

Previous studies describing drill trajectory for single incision distal biceps tendon repair suggest aiming ulnar and distal (Lo et al). This suggests that the starting point of the drill would be anterior and radial to the anatomic insertion of the distal biceps tendon. Restoration of the anatomic footprint may be important for restoration of normal strength, especially as full supination is approached. To determine the safest drill trajectory for preventing injury to the posterior interosseous nerve (PIN) when repairing the distal biceps tendon to the ANATOMIC footprint through a single-incision anterior approach utilising cortical button fixation. Through an anterior approach in ten cadaveric specimens, three drill holes were made in the radial tuberosity from the centre of the anatomic footprint with the forearm fully supinated. Holes were made in a 30º distal, transverse and 30º proximal direction. Each hole was made by angling the trajectory from an anterior to posterior and ulnar to radial direction leaving adequate bone on the ulnar side to accommodate an eight-millimetre tunnel. Proximity of each drill trajectory to the PIN was determined by making a second incision on the dorsum of the proximal forearm. A K-wire was passed through each hole and the distance between the PIN and K-wire measured for each trajectory. The PIN was closest to the trajectory K-wires drilled 30° distally (mean distance 5.4 mm), contacting the K-wire in three cases. The transverse drill trajectory resulted in contact with the PIN in one case (mean distance 7.6 mm). The proximal drill trajectory appeared safest with no PIN contact (mean distance 13.3 mm). This was statistically significant with a Friedman statistic of 15.05 (p value of 0.00054). When drilling from the anatomic footprint of the distal biceps tendon the PIN is furthest from a drill trajectory aimed proximally. The drill is aimed radially to minimise blowing out the ulnar cortex of the radius. For any reader inquiries, please contact . vansurgdoc@gmail.com

Rotator cuff repair is performed to treat shoulder pain and disability. Failure of the tendon repair site is common; one strategy to improve healing is to enforce a period of post-operative immobilisation. Immobilisation may have unintended effects on tendon healing. Tenocytes under uniaxial strain form more organised collagen and up regulate expression of proliferative genes. Vitamin C (ascorbic acid), an anti-oxidant that is a co-factor for collagen synthesis, has also been reported to enhance collagen deposition and organisation. The purpose of this study was to compare human tenocyte cultures exposed to uniaxial cyclical strain with or without slow-release ascorbic acid (ascorbyl-2 phosphate) to determine their individual and combined effects on tissue remodelling and expression of tissue repair genes. Rotator cuff tissues were collected from degenerative supraspinatus tears from eight patients. Tenocytes were incorporated into 3D type I collagen culture matrices. Cultures were divided into four groups: 1) ascorbic acid (0.6mMol/L) + strain (1%–20% uniaxial cyclic strain at 0.1 Hz), 2) ascorbic acid unstrained, 3) strain + vehicle 4) unstrained + vehicle. Samples were fixed in paraffin, stained with picrosirius red and analysed with circular polarising light. A second set of cultures were divided into three groups: 1) 0.5mM ascorbic acid, 2) 1mM ascorbic acid, 3) vehicle cultured for 24, 72, 120 and 168 hours. Cell-free collagen matrix was used as a control. Tenocyte proliferation was assessed using the water soluble tetrazolium-1 (WST1) assay and f tissue repair gene expression (TGFB1, COL1A1, FN1, COLIII, IGF2, MMP1, and MMP13), were analysed by qPCR. The data were analysed using a Split model ANOVA with contrast and bonferroni correction and a one-way ANOVAs and Tukey's test (p<0.05 was significant). Our results indicated that unstrained cultures with or without exposure to slow release ascorbic acid exhibited greater picrosirius red birifringency and an increase in collagen fiber deposition in a longitudinal orientation compared to strained tenocytes. We found that slow release ascorbic acid promoted significant dose and culture-time dependent increases in tenocyte proliferation (p<0.05) but no obvious enhancement in collagen deposition was evident over cultures without ascorbic acid supplementation. Based on these data, applying strain to tenocytes may result in less organised formation of collagen fibers, suggestive of fibrotic tissue, rather than tendon remodelling. This may indicate that a short period of immobilisation post-rotator cuff repair is beneficial for the healing of tendons. Exposure to slow release ascorbic acid enhanced tenocyte proliferation, suggesting that supplementation with Vitamin C may improve tendon repair post-injury or repair. Future studies will assess levels of tissue repair-associated proteins as well as comparing traumatic and degenerative rotator cuff tears to healthy uninjured rotator cuff tissue

Surgical reattachment of torn rotator cuff tendons can lead to satisfactory clinical outcome but failures remain common. Ortho-R product is a freeze-dried formulation of chitosan (CS) that is solubilized in platelet-rich plasma (PRP) to form injectable implants. The purpose of the current pilot study was to determine Ortho-R implant acute residency, test safety of different implant doses, and assess efficacy over standard of care in a sheep model. The infraspinatus tendon (ISP) was detached and immediately repaired in 22 skeletally mature ewes. Repair was done with four suture anchors in a suture bridge configuration (n = 6 controls). Freeze-dried formulations containing 1% w/v chitosan (number average molar mass 35 kDa and degree of deacetylation 83%) with 1% w/v trehalose (as lyoprotectant) and 42.2 mM calcium chloride (as clot activator) were solubilized with autologous leukocyte-rich PRP and injected at the tendon-bone interface and on top of the repaired site (n = 6 with a 1 mL dose and n = 6 with a 2 mL dose). Acute implant residency was assessed histologically at 1 day (n = 2 with a 1 mL dose and n = 2 with a 2 mL dose). Outcome measures included MRI assessment at baseline, 6 weeks and 12 weeks, histopathology at 12 weeks and clinical pathology. MRI images and histological slides were scored by 2 blinded readers (veterinarian and human radiologist, and veterinarian pathologist) and averaged. The Generalized Linear Model task (SAS Enterprise Guide 7.1 and SAS 9.4) was used to compare the different groups with post-hoc analysis to test for pairwise differences. Ortho-R implants were detected near the enthesis, near the top of the anchors holes and at the surface of ISP tendon and muscle at 1 day. Numerous polymorphonuclear cells were recruited to the implant in the case of ISP tendon and muscle. On MRI, all repair sites were hyperintense compared to normal tendon at 6 weeks and only 1 out 18 repair sites was isointense at 12 weeks. The tendon repair site gap seen on MRI, which is the length of the hyperintense region between the greater tuberosity and tendon with normal signal intensity, was decreased by treatment with the 2 mL dose when compared to control at 12 weeks (p = 0.01). Histologically, none of the repair sites were structurally normal. A trend of improved structural organization of the tendon (p = 0.06) and improved structural appearance of the enthesis (p = 0.1) with 2 mL dose treatment compared to control was seen at 12 weeks. There was no treatment-specific effect on all standard safety outcome measures, which suggests high safety. Ortho-R implants (2 mL dose) modulated the rotator cuff healing processes in this large animal model. The promising MRI and histological findings may translate into improved mechanical performance, which will be assessed in a future study with a larger number of animals. This study provides preliminary evidence on the safety and efficacy of Ortho-R implants in a large animal model that could potentially be translated to a clinical setting

Aim. The purpose of this study was to develop and test the utility of a hybrid barbed-suture in the core repair of digital flexor tendon injuries. Despite offering advantages over traditional suture methods, concerns over the cost, strength to failure and biocompatibility of barbed sutures have hindered their development. Moreover the recent designs have been very complex. We have attempted to develop and test a simple barbed suture, to assess it's viability in flexor tendon repair and in particular to establish a baseline for the efficacy and modes of failure barbed sutures, in order to help provide a basis for future research. Method. The barbed suture device was constructed by inserting 3 steel barbs into the weaved construct of a braided polyester suture. The barbed sutures were inserted into 28 porcine lateral extensor tendons yielding a single sided core repair. Tensile testing of the repair was undertaken using a tabletop load frame with the distal end of the tendon fixed in a cryo clamp. Linear load testing to failure was undertaken. Maximum load, repair excursion and repair stiffness were recorded. Results. The barbed suture technique demonstrated a maximum load to failure of 40.4±16.4N. The excursion of the repair at failure point was 31.4±11.6mm. The stiffness of the repair derived from the linear elastic portion of the load displacement curve was 1.0±0.6N/mm. Conclusions. Use of this barbed suture construct offers a fast, easily applied method of flexor tendon repair. The maximum load to failure is comparable to the commonly used non-barbed suture methods. The suture excursion and stiffness findings suggest gap formation at low loads. Failure of the barbed suture seemed to be resisted by the collagen links between longitudinal tendon fibres. Further developments of this very modifiable construct may lead to a viable alternative to the current repair techniques

Operative repair of tendo Achilles ruptures is associated with a lower re-rupture rate. A medial approach is made and the tendon ends debrided. The tendon is repaired with two non-absorbable core sutures and an absorbable perimeter suture, with care to avoid any lengthening of the musculotendinous unit. The tendon sheath is repaired, with a deep fascial releasing incision to allow apposition of the edges if necessary. In the case of insertional avulsions, the avulsed bony fragment is excised and the tendon repaired to bone with a 3.5 mm corkscrew anchor and non-absorbable suture. A frontslab is applied with the ankle in gravitational equinus and worn for eight weeks with protected weight bearing. Sutures are removed at 10 to 14 days and active range of motion commenced. At eight weeks, weight bearing as tolerated is allowed with a heel raise and physiotherapy for calf strenghthening is commenced. Recovery of full strength will take one year

Our study aims to demonstrate the efficacy of using endobutton and interference screw technique in the repair of acute distal biceps ruptures. From April 2009 to May 2013, 25 consecutive patients had acute distal biceps tendon repairs using an endobutton and interference screw technique. 3 patients were lost to follow up leaving 22 patients for review. Mean follow up was 24 months (1–51). All were evaluated using a questionnaire, examination, radiographs, power measurements, and Oxford Elbow (OES) and MAYO scores. Overall 95% patients (21/22) felt that their surgery was successful and rated their experience as excellent or good. Mean return to work was 100 days (0–280) and mean postoperative pain relief was 23 days (1–56). 55% returned to sport at their pre-injury level. There was one case (4.5%) of heterotopic calcification with 3 superficial infections (14%). There were no intra or postoperative radial fractures, metalwork failures or metalwork soft tissue irritations. Mean pre-operative OES were 18 (6–37) and post operative 43 (24–48) (p < 0.01). Mean pre-operative Mayo scores were 48 (5–95) and post-operative 95 (80–100) (p < 0.01). Our study supports that distal biceps repairs' with endobutton and interference screw technique appears to lead to high patient satisfaction rates with a relatively early return to function

We present a biomechanical cadaveric study investigating the effect of type II Superior Labrum Anterior Posterior (SLAP) lesions on the load-deformation properties of the Long Head of Biceps (LHB) and labral complex. We also report our assessment of whether repair of the type II SLAP lesion restored normal biomechanical properties to the superior labral complex. Using a servo-controlled hydraulic material testing system (Bionix MTS 858, Minneapolis, MA), we compared the load-deformation properties of the LHB tendon with:. the LHB anchor intact;. a type II SLAP lesion present;. following repair with two different suture techniques (mattress versus ‘over-the-top’ sutures). Seven fresh-frozen, cadaveric, human scapulae were tested. We found that the introduction of a type II SLAP lesion significantly increased the toe region of the load deformation curve compared to the labral complex with an intact LHB anchor. The repair techniques restored the stiffness of the intact LHB but failed to reproduce the normal load versus displacement profile of the labral complex with an intact LHB anchor. Of the two suture techniques, the mattress suture best restored the normal biomechanics of the labral complex. We conclude that a type II SLAP lesion significantly alters the biomechanical properties of the LHB tendon. Repair of the SLAP lesion only partially restores the biomechanical properties. We hypothesise that repairs of type II SLAP lesions may fail at loads as low as 150N, hence the LHB should be protected following surgery