A Comparison of Casting Versus Splinting for Nonoperative Treatment of Pediatric Phalangeal Neck Fractures.

BACKGROUND: Phalangeal neck fractures account for 13% of pediatric finger fractures. Al Qattan type I (undisplaced) fractures are treated nonoperatively. There is increasing evidence that Type 2 (displaced) fractures achieve remarkable fracture remodeling with nonoperative treatment and patients frequently make a full functional recovery. The options available for nonoperative management of these fractures are either a plaster cast or a removable splint. We hypothesized that there would be no significant difference in radiologic outcome in pediatric phalangeal neck fractures (Types I and II) treated with splint or cast immobilization. METHODS: This is a retrospective study of patients aged 18 and below with phalangeal neck fractures treated nonoperatively from 2008 to 2017. Radiographs were compared at <1 week and >3 weeks after injury. Translation and angulation in coronal and sagittal planes were measured and compared using Student t tests. Baseline variables were compared using χ or Fisher exact tests. RESULTS: There were 47 patients with phalangeal neck fractures treated nonoperatively during the study period. There were 9 type I and 38 type II fractures. The mean age was 10 years with 40 males and 7 females. Fractures occurred in 33 dominant and 14 nondominant hands and involved 29 proximal and 18 middle phalanges. Nineteen children were treated in casts and 28 with removable splints. The mean duration of follow-up was similar between the 2 groups. The most affected phalanx was the proximal phalanx of the small finger and the most common fracture pattern was type IIA. There was no significant difference in clinical and radiologic outcomes between children who were treated in casts and those treated in removable splints. CONCLUSION: There was no difference in the clinical and radiologic outcomes in pediatric phalangeal neck fractures treated with cast or splint immobilization. Splinting has the added benefits of increased comfort and hygiene and we routinely offer splinting as a viable alternative in the nonoperative treatment of Al Qattan type I and type II phalangeal fractures. TYPE OF STUDY/LEVEL OF EVIDENCE: Level III-therapeutic studies.

The Effects of Autologous Platelet-Rich Fibrin on Flexor Tendon Healing in a Rabbit Model.

PURPOSE: Platelet-rich plasma containing large amounts of growth factors is purported to increase repaired flexor tendon strength. However, the use of bovine thrombin has the risk of antibody formation. We evaluated the effects of the newer generation autologous platelet-rich fibrin (PRF) on flexor tendon healing. METHODS: We performed surgical repair of 32 flexor tendons from the index and ring digits of the hind paws of 8 New Zealand white rabbits. In the PRF group, the PRF membrane was either wrapped around or interposed between the repair sites. At 3 weeks after surgery, the tested tendons were subjected to range of motion analysis, cross-sectional area measurement, biomechanics testing, and histological analysis. RESULTS: The results showed no significant increase in range of motion in the PRF group compared with the control group, but there was a significant increase in cross-sectional area of the tendons in the PRF group. The biomechanical testing suggested that the control had a higher load to failure and stress to failure but similar stiffness and modulus to the PRF group. CONCLUSIONS: The PRF did not have a major influence on cellular organization. It also had an undesirable effect on the biomechanical properties of repaired flexor tendons. CLINICAL RELEVANCE: The findings of this study suggest PRF may, in certain situations, hinder rather than enhance, the healing for repaired flexor tendons.

Biomechanical comparison of different suturing techniques in rabbit medial gastrocnemius muscle laceration repair.

INTRODUCTION: Skeletal muscle laceration is a common injury. Repair of disrupted delicate tissue is still a clinical challenge for surgeons. A few different muscle repair techniques have been reported. However, the best muscle repair technique has not been identified. The aim of the present study is to compare the biomechanical features of different repair techniques in muscles to identify the most effective one. MATERIAL AND METHODS: New Zealand white rabbits (2.5-3 kg) were euthanized and medial gastrocnemius muscles were isolated. The muscles were completely transected with scalpels and then repaired by 3 different techniques, namely, (1) 2-strand mattress, (2) 4-strand Kessler (with epitendinous suture), and (3) Mason-Allen. To measure suture performance, the repaired specimens were mounted onto a mechanical testing machine Instron 5543. The muscles were loaded to failure at a constant speed of 60 mm/min. Data collected from Merlin v5.31 software were used to compute the biomechanical properties of each specimen. RESULTS: There was no significant difference in the mean maximum load of Kessler group (15.5 N) and Mason-Allen group (13.2 N), whereas the mean maximum load of the control (Mattress) group (4.4 N) was significantly smaller than the other 2 groups. Moreover, Kessler stitches were the stiffest among the 3. It is noteworthy that the mechanisms of failure were different: Kessler stitches were all pulled out longitudinally, whereas Mason-Allen stitches transmitted load across the laceration and ruptures occur at areas adjacent to the stitches, indicating that muscle is the weakest element in the biomechanical testing. CONCLUSIONS: Both Kessler and Mason-Allen stitches have shown better biomechanical features compared with the control group. Further study has to be done to compare the effect of these 2 techniques on muscle regeneration and scar formation in an in vivo model.

Challenges and Solutions in Prosthetic Fitting of Digits after Flap Reconstruction.

Surgical reconstruction can restore length and function, but cannot adequately resolve the problem of disfigurement. Prosthetic fitting can play a complementary role in enhancing the aesthetic outcomes post reconstruction. However, complex reconstruction involving flaps coupled with the surgical imperative for limb length preservation can lead to outcomes where the reconstructed stumps are challenging to fit with prosthesis. This article describes how prosthetic fitting was tackled in a case of a triple-digit amputation after reconstruction that presented with finger stumps that were bulky, long and stiff in extension contracture, compounded by the presence of substantive scar tissues. We discuss major prosthesis modifications that were unconventional but necessary to enable fitting, the techniques involved, as well as the aesthetic and functional considerations behind the modifications. The results showed that enhanced aesthetic appearance, together with a marginal improvement in hand function, was achieved post-prosthetically, meeting the patient's and the clinical team's fitting objective. Level of Evidence: Level V (Therapeutic).

Color-matching techniques for creating esthetic hand and finger prostheses.

BACKGROUND: Color matching is a critically important part of, and by far, also the most challenging aspect of producing esthetic silicone prosthesis. There is a knowledge gap in the literature and a lack of opportunities for training in the expertise, particularly regarding color-matching techniques. OBJECTIVE: This article details a color-matching technique that is able to achieve life-like coloration in esthetic prosthesis. TECHNIQUE: Each prosthesis is molded in an outer and inner layers of silicone tinted to different shades and opacities incorporating an intermediate touch-up layer to reproduce the detailed coloration of the hand (because of the presence of veins, finger joint/dermal pigmentations, a vascularized nail bed, and pinkish palm). This method of color-matching prosthesis combining intrinsic and extrinsic techniques simulates the layered anatomy and optical properties of the human skin to effectively replicate its esthetic and life-like coloration. Technical tips for achieving an accurate color match to the patient's skin, including pigment formulation adjustments for a tanned vs. a fair skin, and for painting the touch-up details are discussed. Methods for modifying the color tones of completed prosthesis and for minimizing metameric color differences when the prosthesis is viewed under different light sources are also presented. DISCUSSION: The technique is instrumental in achieving good outcomes for life-likeness and esthetic coloration in the prostheses fitted at our center. Studies previously published that investigated patients' evaluation of important esthetic characteristics of their prosthesis after a period of adjustment to fitting have shown a generally high level of patient satisfaction.

Functional use of esthetic hand prosthesis: A patient's perspective.

Published reports on the functional benefits of esthetic prosthesis are based on either anecdotal evidence or simplified, nonstandard forms of hand function evaluation performed by the researcher. It is not clear whether and how patients actually make functional use of their prosthesis on a daily basis. We report a case of a patient with a partial hand amputation who was initially ambivalent about fitting an esthetic prosthesis, but went on to make functional use of her prosthesis for activities of daily living, work, and social life at 3 years after injury. We present the patient's own assessment and video recordings, made without influence from rehabilitation personnel that demonstrates this functional use. From this case, we discuss the important factors of a favorable residual limb type, together with targeted modifications made to the prosthesis to optimize function.

Novices can assess microsurgery performance, and this is enhanced using the Manual Suture Parameters for Training and Assessment (M-SParTA) scoring system.

This study explores how novices could effectively evaluate the quality of microsurgical suturing. That would be enhanced with using a novel Manual Suture Parameters for Training and Assessment (M-SParTA), which supported novices with guidance on the objective parameters, in order to increased the accuracy of scoring ability. We also propose the following initial framework to train novices in microsuturing using a standardised task: 1) Exposure; 2) Assessment; 3) Hands-on and self-assessment. The independent learning cycle with targeted supervision provides novices with greater autonomy and a less stressful environment that could enhance skills training.

Surgical Anatomy and Exercises Using the Chicken Thigh Sciatic Nerve for Microsurgery Training.

Introduction Vessel repair in a chicken thigh is commonly used in microsurgery training model. The sciatic nerve is closely associated with the vessels and has been used for training nerve coaptation, which has different technical considerations from vessel anastomosis. We describe in detail the relevant surgical anatomy and training exercises that can be used with this model. Methods With 32 fresh store-bought chicken thighs, 16 were used to analyze the gross and histological features of the sciatic nerve, and 16 were intended to create and perform training models. Results The average visible length of the nerve in the thigh was 51 mm (standard deviation [SD] 2.57 mm). The average diameter of the nerve was 2 mm (SD 0.33 mm) and was largest at its proximal end (3.21 mm, SD 0.27 mm). The nerve consistently branched into two along the chicken thigh, with more branching subsequently. This simulation model is appropriate not only for the classical end-to-end epineural suture, but also for advanced exercises, in terms of longitudinal fasciculus dissection, mismatched size nerve transfer, injured nerve preparation, and vein conduit technique. Dyeing of nerve fascicles enhanced the visibility of nerve surface quality. Conclusion The sciatic nerve in the chicken thigh is a suitable and accessible model for microsurgery training. The branching and fascicular patterns of the nerve lends itself well to both novice training and advanced simulation. We have incorporated this model into our training curricula.

Hand fractures in children: epidemiology and misdiagnosis in a tertiary referral hospital.

PURPOSE: To determine the local epidemiology of pediatric hand fractures and the rate of misdiagnosis. METHODS: A retrospective study was performed on children aged 17 years and younger who were referred for actual or suspected metacarpal and phalangeal fractures. Medical records were reviewed for age at the time of injury, sex, fracture pattern, venue where the injury was sustained, injury mechanism, and diagnoses made by the referring doctor and hand surgeon. Differing diagnoses were considered misdiagnoses. The misdiagnosis rate was calculated as the percentage of misdiagnoses over the number of referrals. RESULTS: Of 204 cases reviewed, emergency physicians referred 146 cases (72%), and primary health care physicians referred the rest. There were 193 cases of actual fractures in 181 patients and 16 cases of misdiagnosis. The fracture incidence peaked at 14 and 15 years. The median ages of children sustaining fractures of the distal phalanges, proximal phalanges, and metacarpals were 9, 12, and 15 years, respectively. The proximal phalanx was most commonly fractured (95 cases, 49%), as was the fifth ray (78 cases, 40%). Most fractures occurred at school (79 cases, 44%). Sports-related injury was the leading cause of fractures (70 cases, 39%). The misdiagnosis rate was 8% (16 of 204). The leading cause of misdiagnosis was misinterpretation of epiphyses (6 of 16), followed by missing multiple fractures (3 of 16). CONCLUSIONS: The higher fracture incidence in teenagers is likely related to sports participation. Sports accounted for proximal fractures in older children, whereas young children sustained distal fractures through crushing injuries. Although the misdiagnosis rate seemed low, it might reflect that emergency physicians, who referred most of the cases, were adept at diagnosing fractures. To improve diagnostic accuracy, doctors should familiarize themselves with the location of epiphyses and look carefully for multiple fractures. TYPE OF STUDY/LEVEL OF EVIDENCE: Economic and Decision Analysis IV.

Volar plating for unstable proximal interphalangeal joint dorsal fracture-dislocations.

PURPOSE: To report our results of open reduction internal fixation with volar mini plate and screw fixation for unstable dorsal fracture dislocations (DFDs) of the proximal interphalangeal (PIP) joint. METHODS: We performed a retrospective review of 13 consecutive DFDs of the PIP joint treated with volar mini plate and screw fixation, measuring both clinical and radiological outcomes. RESULTS: The age range of our patients was 15 to 56 years (average, 33 y). Six injuries were related to work, 5 to sports, and 2 to motor vehicle accidents. Of the 13 DFDs, 6 were comminuted. Articular involvement ranged from 30% to 70% (average, 44%). The average time to surgery was 7 days (range, 0-23 d). Patients had follow-up of 12 to 60 months (average, 25 mo). Four patients had a postoperative course complicated by plate and screw removal at an average of 4 months later, either as part of a secondary procedure to improve range of motion or owing to patient request. All patients returned to their original occupation. Of the 13 patients, 11 were satisfied with the result, and 12 of 13 had either no or mild pain. All 13 DFDs united in good alignment but 3 showed degenerative changes. Average grip strength was 85% of the unaffected side, and average active PIP joint and distal interphalangeal joint motion arcs were 75° and 65°, respectively. Average Quick Disabilities of Arm, Shoulder, and Hand score was 4 (range, 0-9). All patients had non-tender swelling of the proximal interphalangeal joints but no signs of flexor tenosynovitis or infection. CONCLUSIONS: Fixation of unstable PIP joint DFDs via a volar approach is technically feasible with mini plates and screws. This treatment allows early active range of motion and provides good objective and subjective outcomes; however, noteworthy complications occurred in 39% of patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

A biomechanical comparison of 3 loop suture materials in a 6-strand flexor tendon repair technique.

PURPOSE: The braided polyblend (FiberWire) suture is recognized for its superiority in tensile strength in flexor tendon repair. The purpose of this study was to compare the biomechanical performance of 3 loop-suture materials used in a locking 6-strand flexor tendon repair configuration: braided polyblend (FiberLoop 4-0), cable nylon (Supramid Extra II 4-0), and braided polyester (Tendo-Loop 4-0). We hypothesized that, using this technique, the braided polyblend suture would give superior tensile strength compared with the other 2 suture materials. METHODS: We divided 30 fresh porcine flexor tendons transversely and repaired each with 1 of the 3 suture materials using a modified Lim-Tsai 6-strand suture technique. We loaded the repaired tendons to failure using a materials testing machine and collected data on the mechanism of failure, ultimate tensile strength, gap strength, and stiffness. RESULTS: Failure mechanisms for the repaired specimens were as follows: the braided polyblend had 50% suture breakage and 50% suture pullout; the cable nylon had 100% suture breakage; and the braided polyester had 80% suture breakage and 20% suture pullout. Specimens repaired with the braided polyblend suture had the highest mean ultimate tensile strength (97 N; standard deviation, 22) and the highest mean gap force (35 N; standard deviation, 7). CONCLUSIONS: This study supports the findings of previous studies showing superior strength of the braided polyblend suture. CLINICAL RELEVANCE: We were able to achieve up to 124 N in ultimate tensile strength and 48 N of gap force with this suture in porcine tendons. This gives greater confidence in starting immediate controlled passive or active rehabilitation after repair of flexor tendon injuries.

Clinical intervention of a tighter-than-tolerated fit of aesthetic hand and finger prosthesis via controlled silicone swelling: A novel, speedier and versatile alternative method.

A tighter-than-tolerated fit of aesthetic hand prosthesis is conventionally rectified by stretching the affected segment to plastic deformation. This method is not only time-consuming, but also ineffective in stretching irregular, non-cylindrical prosthesis segments apart from the "wrist and digits". This study investigates controlled silicone swelling as an alternative method of expanding aesthetic hand and finger prosthesis to address a tight fit. The technique of "controlled" swelling that minimizes oil uptake to as little as is necessary to achieve the desired magnitude of elastomer expansion was demonstrated using experimental test samples. Brush-coats of a cosmetics-grade oil, KF-96A-10CS, 2 a time, were applied on CosmesilTM samples to obtain elastomer expansion. The same technique of staggered oil delivery was used on tight-fitting segments of patients' prosthesis, with test-fitting of each incremental expansion till satisfactory outcomes were achieved. Percentage circumference increases in swelled test samples and in all rectified/ patients' prostheses were then compared to validate the effectiveness of the method. Circumference increases in the test samples after each 2 coats were significantly different (P <.001). Representative (unreinforced) Samples 1, 2, and 3 recorded circumferential increases of 4.0% to 11.4% within 30 minute after swelling by 2.6% to 9.7% from 2 to 6 oil coats. This largely correlated with patient data, where circumferential increases of 3.6% to 9.5% from 2 to 6 oil coats were collectively recorded in all fit-rectified finger prostheses. Swelling in the expanded proximal segment of all 24 finger prostheses was estimated to be within 9.7%. Of these, 22 (92%) required 2 to 4 oil coats, inferring a lower still swelling of 6.5%. The rapid and consistent elastomer expansion enabled prosthetic fit rectification to be achieved in a much shortened time. Clinical outcomes indicated that low swelling magnitudes involving small amounts of 2 to 6 brush-coats of oil have no adverse effects on the prostheses. None of the participating patients had reported any incidence of discernible change in all of the important properties of their prostheses. Outcomes based on the CosmesilTM-KF-96A-10CS elastomer-oil combination demonstrated that controlled silicone swelling involving minimal use of oil is an effective method of intervention for a tighter-than-tolerated prosthetic fit of silicone hand and fingers.

Secondary Procedures after Severe Upper Extremity Injury.

Upper extremity trauma is one of the most common types of injuries, accounting for 20 to 40 percent of injured patients presenting to the emergency department. In severe upper extremity injury, the likelihood of secondary procedures to improve function and resolve outstanding clinical problems is high. Secondary procedures are performed later than initial primary surgery, usually after wound healing and with a discernible time gap of days, weeks or occasionally longer. They should be considered as separate procedures from the primary surgery, with due diligence given to planning for it. When approaching secondary procedures, the key principles are anchored in early preparation, patient engagement, optimal timing and sequencing, reviewing and considering alternatives, and finally knowing when to stop. Although secondary procedures after upper extremity injuries can be a complex undertaking, the careful application of these principles and considerations will optimise outcomes.

Randomized controlled trial comparing the effectiveness of mass and spaced learning in microsurgical procedures using computer aided assessment.

Spaced-learning refers to teaching spread over time, compared to mass-learning where the same duration of teaching is completed in one session. Our hypothesis is that spaced-learning is better than mass-learning in retaining microsurgical suturing skills. Medical students were randomized into mass-learning (single 8-h session) and spaced-learning (2-h weekly sessions over 4 weeks) groups. They were taught to place 9 sutures in a 4 mm-wide elastic strip. The primary outcome was precision of suture placement during a test conducted 1 month after completion of sessions. Secondary outcomes were time taken, cumulative performance, and participant satisfaction. 42 students (24 in the mass-learning group; 18 in spaced-learning group) participated. 3 students in the spaced-learning group were later excluded as they did not complete all sessions. Both groups had comparable baseline suturing skills but at 1 month after completion of teaching, the total score for suture placement were higher in spaced-learning group (27.63 vs 31.60,p = 0.04). There was no statistical difference for duration and satisfaction in either group. Both groups showed an improvement in technical performance over the sessions, but this did not differ between both groups. Microsurgical courses are often conducted in mass-learning format so spaced learning offers an alternative that enhances retention of complex surgical skills.

Pediatric Hand and Wrist Fractures.

Hand and wrist fractures are common in the pediatric population. Accurate diagnosis relies on the understanding of the physeal anatomy and carpal ossification. Treatment of these fractures is largely influenced by physeal biology and compliance with treatment. A majority have a favorable outcome with nonoperative treatment. Operative treatment should be considered in patients with clinical deformity, open fractures, and significant fracture displacement. Physeal-friendly surgical approaches and implants should be used to minimize the sequelae of physeal injury.

External bleeding versus dermal pocketing for distal digital replantation without venous anastomosis.

Venous congestion in distal digital replantations is a common problem as suitable veins are not always available. We compared two methods of venous decongestion, external bleeding ( n = 15) and dermal pocketing ( n = 28) carried out when venous anastomosis was not possible. The findings of this small study suggest that neither method of venous decongestion is clearly better than the other. Level of evidence: IV.

Optimization of flexor tendon tissue engineering with a cyclic strain bioreactor.

PURPOSE: Mechanical manipulation of cultured tendon cells can enhance cell proliferation and matrix production. This study aims to determine the bioreactor strain patterns (amplitude, frequency, and on/off ratio) that favor cellular proliferation, promote collagen production, and maintain morphology in candidate cell lines cultured for flexor tendon tissue engineering, including multipotent stromal cells. METHODS: We studied epitenon tenocytes (Es), sheath fibroblasts (Ss), bone marrow-derived mesenchymal stem cells (BMSCs), and adipoderived stem cells (ASCs). We examined the effects of 3 patterns of cyclic uniaxial strain on cell proliferation, collagen I production, and cell morphology. RESULTS: Adipoderived stem cells (33% adhesion) and Ss (29%) adhered more strongly to bioreactor membranes than did Es (15%) and BMSCs (7%), p=.04. Continuous cyclic strain (CCS, 8%, 1 Hz) inhibited cell proliferation (p=.01) and increased per-cell collagen production (p=.04) in all cell types. Intermittent cyclic strain (4%, 0.1 Hz, 1 hour on/5 hours off) increased proliferation in ASCs (p=.06) and Ss (p=.04). Intermittent cyclic strain (4%, 0.1 Hz, 1 hour on/2 hours off) increased total collagen production by 25% in ASCs (p=.004) and 20% in Ss (p=.05). Cyclic strain resulted in cell alignment perpendicular to the strain axis, cytoskeletal alignment, and nuclear elongation. These morphological characteristics are similar to those of tenocytes. CONCLUSIONS: These results demonstrate that intermittent cyclic strain can increase cell proliferation, promote collagen I production, and maintain tenocyte morphology in vitro. Use of a cell bioreactor might accelerate the in vitro stage of tendon tissue engineering.

The effects of bi-functional anti-adhesion scaffolds on flexor tendon healing in a rabbit model.

Progressive tendon adhesion is a major challenge in flexor tendon repair. The authors developed a bifunctional anti-adhesion scaffold and hypothesized that its application would reduce adhesion formation and deliver mesenchymal stem cells (MSCs) to enhance tendon healing. The scaffold was fabricated by an electrospinning machine before surface modification. The flexor tendons of 29 New Zealand rabbits underwent surgical repair and randomized to control, scaffold and scaffold loaded with MSC group. At 3 and 8 weeks post-surgery, range of motion (ROM), biomechanical properties, and histology were examined. There was no significant increase in ROM and biomechanical properties between the three groups. The histology showed successful delivery of MSCs but no significant difference in nuclear morphometry. This barrier delivers and retains MSCs within the tendon repair site. However, its sheet form and wrapping around the repair site may not be optimal for tendon healing. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2605-2614, 2018.

Bone marrow-derived mesenchymal stem cells influence early tendon-healing in a rabbit achilles tendon model.

BACKGROUND: A repaired tendon needs to be protected for weeks until it has accrued enough strength to handle physiological loads. Tissue-engineering techniques have shown promise in the treatment of tendon and ligament defects. The present study tested the hypothesis that bone marrow-derived mesenchymal stem cells can accelerate tendon-healing after primary repair of a tendon injury in a rabbit model. METHODS: Fifty-seven New Zealand White rabbits were used as the experimental animals, and seven others were used as the source of bone marrow-derived mesenchymal stem cells. The injury model was a sharp complete transection through the midsubstance of the Achilles tendon. The transected tendon was immediately repaired with use of a modified Kessler suture and a running epitendinous suture. Both limbs were used, and each side was randomized to receive either bone marrow-derived mesenchymal stem cells in a fibrin carrier or fibrin carrier alone (control). Postoperatively, the rabbits were not immobilized. Specimens were harvested at one, three, six, and twelve weeks for analysis, which included evaluation of gross morphology (sixty-two specimens), cell tracing (twelve specimens), histological assessment (forty specimens), immunohistochemistry studies (thirty specimens), morphometric analysis (forty specimens), and mechanical testing (sixty-two specimens). RESULTS: There were no differences between the two groups with regard to the gross morphology of the tendons. The fibrin had degraded by three weeks. Cell tracing showed that labeled bone marrow-derived mesenchymal stem cells remained viable and present in the intratendinous region for at least six weeks, becoming more diffuse at later time-periods. At three weeks, collagen fibers appeared more organized and there were better morphometric nuclear parameters in the treatment group (p < 0.05). At six and twelve weeks, there were no differences between the groups with regard to morphometric nuclear parameters. Biomechanical testing showed improved modulus in the treatment group as compared with the control group at three weeks (p < 0.05) but not at subsequent time-periods. CONCLUSIONS: Intratendinous cell therapy with bone marrow-derived mesenchymal stem cells following primary tendon repair can improve histological and biomechanical parameters in the early stages of tendon-healing.