Intrasynovial Tendon Research Articles

Pyramid of progressive force exercises to the injured flexor tendon

Postoperative rehabilitation for patients who have sustained a laceration to their flexor tendon apparatus is an important factor in maximizing functional outcome. Quality rehabilitation is characterized by the development of a tailored exercise regimen. There is currently no model available to tailor an exercise regimen for a person with an atypical physiologic response pattern. If rehabilitation protocols were classified according to the criteria of forces applied across a tendon juncture and/or excursion, and a clinical method were available to assist in the identification of optimal tendon loading and/or excursion application, then those individuals with atypical response patterns could be treated more efficiently and effectively. The author conducted a literature review and case study. A model for systematic application of progressive loading exercises to the intrasynovial flexor tendon injury and repair is conceptually developed. The model consists of a pyramidal series of eight specific rehabilitation exercises in the following sequence: passive protected extension, place and hold, active composite fist, hook and straight fist, isolated joint motion, resistive composite fist, resistive hook and straight fist, and resistive isolated joint motion. Concepts are developed to implement a three-point clinical adhesion-grading system. Clinical application of the system is highlighted. An excellent outcome was considered 112% total active motion. A model for systematic application of progressive loading exercises has been conceptually developed in concert with a method for determination of optimal tendon loading. Further substantiation is necessary to validate the proposed theory.

Eight-Strand Core Suture Technique for Repair of Intrasynovial Flexor Tendon Lacerations

The concept of intrinsic tendon healing, the idea that tendons can heal primarily without the ingrowth of fibrous adhesions from the surrounding fibrous flexor sheath, has been validated both experimentally and clinically. The goals of the surgical treatment of intrasynovial digital flexor tendon lacerations are twofold: 1) to achieve a primary tendon repair of sufficient strength so as to prevent repair site gap elongation and possible rupture, and 2) to prevent the formation of intrasynovial adhesions that cause loss of tendon excursion within the flexor tendon sheath. It is well accepted that repair site strength, both at time zero and within the first 6 postoperative weeks, is directly related to the number of core suture strands crossing the repair site. The factor that limits more widespread use of multistrand suture techniques remains the surgeon's ability to perform the repair while also minimizing trauma to the tendon stumps and the circumferential epitenon. We describe an 8-strand core suture technique used at our institution that has been tested ex-vivo, in-vivo in canines, and used in human subjects over the last 4 years with excellent results.

Neovascularization of the flexor digitorum profundus tendon after avulsion injury: An in vivo canine study

Purpose: The changes in matrix material properties and intrinsic vascularization that have been noted in intrasynovial tendon stumps after avulsion injury may be of considerable clinical relevance with regard to the results of surgical repair. Our objective was to determine both the time course and the source of neovascularization of the tendon stump in an in vivo canine model of flexor digitorum profundus (FDP) avulsion after a clinically relevant delay in diagnosis. Method: The FDP tendon was released from bone directly by sharp dissection and the vinculum brevis profundus was lacerated, simulating an avulsion injury with interruption of the vascular supply to the tendon stump. After death at 7 and 21 days, tendon vascularity was evaluated with India ink injection and clearing using a modified Spalteholtz technique. Results: All 7-day specimens showed an absence of vascularity compared with the controls. In all 21-day specimens a direct vascular supply originated from local fibrovascular adhesions contacted the stump on its surface and blood vessels penetrated the tendon stump circumferentially. Progressive vascularization of the avulsed tendon stump occurred between 7 and 21 days after injury, originating from fibrovascular adhesions to the surrounding synovial sheath. Conclusions: Whereas previous studies of intrasynovial flexor tendon laceration and repair have shown a progressive proximal to distal neovascularization of the FDP during the early postoperative period, longitudinal proximal to distal growth from the proximal blood supply of the FDP was not observed toward the unrepaired tendon stump. (J Hand Surg 2003;28A:231-236. Copyright © 2003 by the American Society for Surgery of the Hand.)

Tendon healing in vitro: Promotion of collagen gene expression by bFGF with NF-κB gene activation

Purpose: Matrix synthesis of intrasynovial tendon cells and activation of nuclear transcription factors are pivotal to promotion of flexor tendon healing. We investigated the effects of basic fibroblast growth factor (bFGF) on synthesis of type I collagen and activation of nuclear transcription factor κB (NF-κB) in an in vitro culture model of intrasynovial tenocytes. Method: Tenocytes obtained from explant culture of rabbit intrasynovial tendon segments were treated with bFGF at concentrations of 0, 2, and 10 ng/mL. Expression of type I collagen and NF-κB genes was determined by quantitative analysis of products of reverse-transcription polymerase chain reactions. Proliferation of the cells was assessed by incorporation of bromodeoxyuridine into the DNA of the cells. Results: Expression levels of type I collagen and NF-κB genes of tenocytes were increased significantly by bFGF. Cell proliferation as indicated by DNA labeling was promoted significantly by bFGF. Expression of the NF-κB gene increased proportionately to the amounts of bFGF stimulating the cells and was correlated with increases in proliferation rate of tenocytes. Conclusions: Results of this study show that expression of type I collagen and NF-κB genes is promoted manifestly by bFGF. The effects were proportionate to in vitro proliferation rates of tenocytes. The study indicated that matrix synthesis of flexor tendons can be promoted by bFGF and that NF-κB may play a pivotal role in initiating proliferation and type I collagen synthesis of tenocytes. (J Hand Surg 2003;28A:215-220. Copyright © 2003 by the American Society for Surgery of the Hand.)

FLEXOR TENDON REPAIR AND REHABILITATION

Basic science and clinical investigation have advanced significantly the treatment and the outcome following intrasynovial flexor tendon repair and rehabilitation and reconstruction over the past 30 years. The application of modern multistrand suture repair techniques as well as postoperative rehabilitation protocols emphasizing the application of intrasynovial repair site excursion has led to a protocol for treatment of intrasynovial flexor tendon lacerations emphasizing a strong initial repair followed by the application of postoperative passive motion rehabilitation. Protocols for the reconstruction of failed initial treatment have likewise undergone modification given new findings on the biologic and clinical behavior of flexor tendon grafts. Currently accepted treatment protocols following flexor tendon repair and reconstruction are based on current clinical and scientific data.

Effect of paratenon and repetitive motion on the gliding resistance of tendon of extrasynovial origin.

We measured the gliding resistance of canine and human tendons of intrasynovial origin and tendons of extrasynovial origin with and without paratenon, and investigated the structure of paratenon using scanning electron microscopy. In the canine study, seven intrasynovial flexor digitorum profundus (FDP) tendons, seven extrasynovial fibularis (peroneus) longus (FL) tendons with paratenon, and seven FL tendons without paratenon were used. In the human study, seven intrasynovial FDP tendons and seven extrasynovial palmaris longus (PL) tendons cut in half (one half with paratenon, the other half without paratenon) were used. The gliding resistance of each tendon was measured at 1, 5, 10, 20, 50, and100 flexion/extension cycles. The canine and human FDP tendons maintained a gliding resistance significantly lower than that of the other tendons at all observation points (P < 0.05). In the canine, the gliding resistance of the FL tendon with paratenon was significantly lower than that of the FL tendon without paratenon up to 50 flexion/extension cycles (P < 0.05), but the two were not significantly different at 100 cycles. In the human, the gliding resistance of PL tendons with paratenon was significantly lower than that of the PL tendons without paratenon at all measuring points (P < 0.05). Preservation of paratenon thus appears to decrease the gliding resistance of extrasynovial tendons after repetitive motion in vitro.

The effect of variations in applied rehabilitation force on collagen concentration and maturation at the intrasynovial flexor tendon repair site

The biochemical means by which accelerated rehabilitation alters intrasynovial flexor tendon repair site collagen synthesis and extracellular matrix maturation are not fully understood. We hypothesized that an increased level of applied rehabilitative force in a clinically relevant animal model would hasten the maturation of the repair site extracellular matrix as demonstrated by total collagen and collagen cross-link assessment. Twenty-eight flexor digitorum profundus tendons from 14 adult dogs were transected and repaired. The animals received either low- or high-force rehabilitation and were killed 10, 21, and 42 days after surgery. A 10-mm segment of tendon surrounding the repair site was obtained. Biochemical analysis showed that total collagen concentration was significantly reduced at each time point, that the reducible cross-link ratio of dihydroxylysinonorleucine to hydroxylysinonorleucine was significantly increased at each time point, and that the nonreducible pyridinoline cross-link content was significantly decreased at 10 days in both rehabilitative groups. Total collagen content did not vary to a statistically significant degree with either time or as a function of rehabilitation type. Based on these findings several clinically relevant observations can be made. Increasing collagen concentration and repair site maturation do not explain the previously demonstrated increased tensile properties of tendon that occur between 3 and 6 weeks after repair. Higher force rehabilitation does not alter the biochemical composition of the healing tendon through 6 weeks. Coupled with other recent data these findings suggest that high-force rehabilitation does not stimulate accelerated healing after intrasynovial flexor tendon repair.

Quantitative variation in vascular endothelial growth factor mRNA expression during early flexor tendon healing: an investigation in a canine model

Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis, with direct mitogenic activity on cells of endothelial origin. We quantified the temporal accumulation of VEGF mRNA at the repair site of an in vivo canine intrasynovial flexor tendon repair and rehabilitation model by means of quantitative Northern blot analysis, in order to detail a molecular signal involved in the intrinsic angiogenic process that accompanies early flexor tendon healing. Significant accumulation of VEGF mRNA occurred at the flexor tendon repair site at 7 days post-operatively, with peak levels seen at post-operative days 7 and 10. Levels returned to baseline by day 14. Local VEGF mRNA accumulation at the repair site temporally precedes and is spatially distinct from the vascular ingrowth itself, which has been shown to occur maximally at day 17. These data suggest that cells within the flexor tendon repair site are involved in molecular processes other than the synthesis of extracellular matrix, such as modulation of angiogenesis.

Intrasynovial Flexor Tendon Repair

Rehabilitation methods that generate increased tendon force and motion have been advocated to improve results following intrasynovial flexor tendon repair. However, the effects of rehabilitation force and motion on tendon-healing may be masked by the high stiffness produced by newer suture methods. Our objective was to determine whether the biomechanical properties of tendons repaired by one of two multistrand suture methods were sensitive to an increased level of applied rehabilitation force. Two hundred and fourteen flexor digitorum profundus tendons from 107 adult dogs were transected and repaired. Dogs were assigned to one of four groups based on the rehabilitation method (low force [<5 N] or high force [17 N]) and the repair technique (four-strand or eight-strand core suture) and were killed between five and forty-two days after the procedure. Repair-site structural properties were determined by tensile testing, and digital range of motion was assessed with use of a motion-analysis system. Tensile properties did not differ between the low and high-force rehabilitation groups, regardless of the repair technique (p > 0.05). In contrast, tensile properties were strongly affected by the repair technique, with tendons in the eight-strand group having an approximately 35% increase in ultimate force and rigidity compared with those in the four-strand group (p < 0.05). Ultimate force did not change significantly with time during the first twenty-one days (p > 0.05); there was no evidence of softening in either of the repair or rehabilitation groups. Force increased significantly from twenty-one to forty-two days, while rigidity increased throughout the forty-two-day period (p < 0.05). Increasing the level of force applied during postoperative rehabilitation from 5 to 17 N did not accelerate the time-dependent accrual of stiffness or strength. Suture technique was of primary importance in providing a stiff and strong repair throughout the early healing interval. Our findings suggest that there be a reexamination of the concept that increases in force produced by more vigorous mobilization protocols are beneficial to tendon-healing. While more vigorous rehabilitation may help to improve hand function, we found no evidence that it enhances tissue-healing or strength in the context of a modern suture repair.

FLEXOR TENDON BLOOD VESSELS

The aim of this study was to assess rabbit long flexor tendon vascularity in a qualitative and quantitative manner using immunohistochemistry. The endothelial cell surface marker CD31 was targeted with a specific monoclonal mouse-anti-human antibody with good species cross-reactivity. Subsequent signal amplification and chromogen labelling allowed vessel visualization. Computer image analysis was performed. Values for vessel number and total vessel area per section, as well as the sections' cross-sectional tendon areas, were obtained.There was a consistent deep tendon avascular zone between the A2 and A4 pulley in the rabbit forepaw. This was not the case in the hindpaw, with dorsally orientated longitudinal vessels coursing the length of the intrasynovial tendon. The area of least vascularity in the hindpaw was around the metacarpophalangeal joint. We therefore recommend the use of hindpaw tendons when using the rabbit as a flexor tendon experimental model. This is because its vascular pattern is similar to that of the human flexor digitorum profundus.

Nonviral in vivo gene therapy for tissue engineering of articular cartilage and tendon repair.

Heretofore, nonviral methods have been used primarily for in vitro transfection of cultured cell lines. These methods were substantially less efficient when compared with the use of viruses, particularly when used in vivo. Herein a three-step, highly efficient method of nonviral gene delivery is presented. Using this method, genes have been delivered successfully into tissues of orthopaedic importance with high-efficiency by nonviral means. Transforming growth factor-beta 1, parathyroid hormone related protein, and a marker gene were transfected into primary perichondrium and cartilage cells with efficiencies in excess of 70%. They overexpressed their cognate gene products showing efficacy of expression in a rabbit model of osteochondral defect repair. Using the same method, a marker gene was delivered into a canine model for intrasynovial flexor tendon injury and repair. This was achieved by direct gene delivery during surgery. An estimated 5 additional minutes were required during surgery to complete the transfection steps. High efficiency gene delivery was achieved in the flexor tendons, tendon sheaths, tendon pulleys, surrounding tissues, and skin. The efficiency of transfection approached 100% in the exposed superficial tissue layers and transfected cells were found several layers below the exposed tissue surfaces. The data show the potential of direct nonviral gene therapy in orthopaedics for ex vivo and in vivo applications.

Flexor tendon grafting to the hand: an assessment of the intrasynovial donor tendon-A preliminary single-cohort study.

We report the results of a pilot study using intrasynovial donor tendons for flexor tendon reconstruction in 8 patients (10 digits) at a mean follow-up time of 3.8 years for neglected or failed primary repair of zone 2 lacerations and for neglected flexor digitorum profundus avulsions. The flexor digitorum longus to the second toe was used as the donor tendon graft. Four patients (4 digits) underwent single-stage reconstruction and 4 patients (6 digits) had multistage reconstruction. The overall patient satisfaction using a standardized visual analog reporting scale was excellent. There was 1 excellent, 1 good, 1 fair, and 1 poor result in the single-stage reconstruction group, including 1 repair site rupture and 1 digit requiring tenolysis. In the multistage reconstruction group there was 1 excellent, 3 good, 1 fair, and no poor results, including 1 digit requiring tenolysis. One patient was lost to follow-up. There was no donor site morbidity. The average active motion recovery was 64% and 56% for single-stage and multistage reconstructions, respectively, and was 73% overall for single digit reconstructions. The results of this pilot study suggest that intrasynovial tendon grafting may offer an improved alternative for tendon grafting to the synovial spaces of the digit.

Advances in the biology of zone II flexor tendon healing and adhesion formation.

There has been dramatic improvement in the results of zone II tendon surgery in the last three decades. This improvement was brought, to a great extent, by the better understanding of the mechanisms of tendon healing. This article provides an overview of the mechanism of intrasynovial tendon healing, the role and origin of fibroblasts, and the effects of extracellular components and various growth factors on tendon healing. It also sheds light on the incidence and significance of tendon adhesions. An account of the ultrastructure of the synovial sheath is presented.

HYALURONIC ACID MODULATES CELL PROLIFERATION UNEQUALLY IN INTRASYNOVIAL AND EXTRASYNOVIAL RABBIT TENDONS IN VITRO

As tendons differ in biochemical composition and cellular capacities, we have compared dose response effects of hyaluronic acid on cell proliferation and synthesis of matrix components in intermediate and proximal segments of intrasynovial deep flexor tendons and extrasynovial peroneus rabbit tendons in vitro. Compared with matched control tendons, hyaluronic acid inhibited cell proliferation in intermediate and proximal intrasynovial flexor tendon segments at the concentrations of 0.1–2.0 mg/ml and 0.5–2.0 mg/ml respectively, but in extrasynovial tendon segments only at the concentration of 0.5 mg/ml. Hyaluronic acid did not affect synthesis of proteoglycan, collagen and non-collagen protein in either type of tendon. These results show that hyaluronic acid modulates cell proliferation unequally in intra- and extrasynovial tendons without affecting the synthesis of matrix components in the two types of tendons, indicating differential hyaluronic acid sensitivity and a possible mechanism of action.

Regulation of alpha(v)beta3 and alpha5beta1 integrin receptors by basic fibroblast growth factor and platelet-derived growth factor-BB in intrasynovial flexor tendon cells.

Integrins are important players in soft tissue healing as molecules that mediate communication between cells and extracellular matrix. Thus, the regulation of the expression of these molecules would be important during wound repair. To explore the regulatory roles of specific growth factors on integrin expression by intrasynovial flexor tendon cells, the present study assessed the in vitro effects of basic fibroblast growth factor and platelet derived growth factor-BB on expression of the alpha5beta1 and alpha(v)beta3 integrins in these cells. Analyses were carried out at the transcriptional (reverse transcription-polymerase chain reaction) and translational (immunohistochemistry) levels of cellular metabolism. Both types of analyses revealed increased expression of alpha5beta1 and alpha(v)beta3 by tendon cells exposed to either basic fibroblast growth factor or platelet-derived growth factor-BB over a wide range of growth factor concentrations employed in the study. Semiquantitative reverse transcription-polymerase chain reaction showed that, relative to control, basic fibroblast growth factor and platelet-derived growth factor-BB increased the expression of alpha(v) mRNA by 2-and 3-fold, respectively. Alpha 5 mRNA expression was also increased 3-fold by basic fibroblast growth factor, and 2-fold by platelet-derived growth factor-BB. We believe the results of this study are significant because the specific integrins affected are intimately involved in two events that have been shown to be important to intrasynovial flexor tendon healing, namely fibronectin deposition (alpha5beta1) as part of the provisional matrix and angiogenesis/revascularization (alpha(v)beta3).

Flexor tendon-tendon sheath interaction after tendon grafting: A biomechanical study in a human model in vitro

A human cadaver tendon sheath model was used to study the differences in excursion resistance of tendons that might be considered as sources of clinical tendon grafts. The flexor digitorum profundus and superficialis tendons, the extensor indicis proprius tendon used in its normal proximal-distal orientation, the extensor indicis proprius tendon used in a reversed distal-proximal orientation, and the palmaris longus tendon were studied in 7 fingers. The intrasynovial tendons (the flexor digitorum profundus and superficialis tendons and the reversed extensor indicis proprius tendon) produced less excursion resistance (p < .05) than the extrasynovial tendons (the normally oriented extensor indicis proprius tendon and the palmaris longus tendon). In contrast to studies measuring resistance against a single pulley, resistance within a complete tendon sheath may be affected by contact with other structures, particularly in joint extension.

Effects of increased in vivo excursion on digital range of motion and tendon strength following flexor tendon repair.

Postoperative rehabilitation is an important factor in determining functional outcome following intrasynovial flexor tendon repair. We hypothesized that a rehabilitation protocol that produced increased in vivo excursion would lead to increased digital range of motion and tendon strength and decreased adhesion formation in a canine model. Ninety-six flexor digitorum profundus tendons from 48 dogs were cut transversely and repaired by a multistrand suture technique. Postoperative rehabilitation was performed daily with a low excursion-low force (1.7-mm average excursion; < 10 N force) or a high excursion-low force (3.6 mm excursion; < 10 N force) protocol. After death of the dogs at 10, 21, or 42 days, specimens were evaluated for digital range of motion, tensile mechanical properties, elongation of the repair site, and adhesion formation. Our data indicate that the range of motion of digits whose tendons were at low or high excursion was similar to that of controls. Increased in vivo tendon excursion due to synergistic wrist motion did not significantly affect ex vivo flexion of the distal and proximal interphalangeal joints or tendon displacement (p > 0.05). Similarly, tensile properties (ultimate load, repair site rigidity, and repair site strain at 20 N and at failure) and length of the gap at the repair site were not significantly affected by increased excursion (p > 0.05). Severity of adhesion formation was reduced slightly by increased excursion (p = 0.04). Our findings indicate that 1.7 mm of tendon excursion is sufficient to prevent adhesion formation following sharp transection of the canine flexor tendon and that additional excursion provides little added benefit.

The effect of gap formation at the repair site on the strength and excursion of intrasynovial flexor tendons. An experimental study on the early stages of tendon-healing in dogs.

Elongation (gap formation) at the repair site has been associated with the formation of adhesions and a poor functional outcome after repair of flexor tendons. Our objectives were to evaluate the prevalence of gap formation in a clinically relevant canine model and to assess the effect of gap size on the range of motion of the digits and the mechanical properties of the tendons. We performed operative repairs after sharp transection of sixty-four flexor tendons in thirty-two adult dogs. Rehabilitation with passive motion was performed daily until the dogs were killed at ten, twenty-one, or forty-two days postoperatively. Eight tendons ruptured in vivo. In the fifty-six intact specimens, the change in the angles of the proximal and distal interphalangeal joints and the linear excursion of the flexor tendon were measured as a 1.5-newton force was applied to the tendon. The gap at the repair site was then measured, and the isolated tendons were tested to failure in tension. Twenty-nine tendons had a gap of less than one millimeter, twelve had a gap of one to three millimeters, and fifteen had a gap of more than three millimeters. Neither the time after the repair nor the size of the gap was found to have a significant effect on motion parameters (p > 0.05); however, the ultimate force, repair-site rigidity, and repair-site strain at twenty newtons were significantly affected by these parameters (p < 0.05). Testing of the tendons with a gap of three millimeters or less revealed that, compared with the ten-day specimens, the forty-two-day specimens failed at a significantly (90 percent) higher force (p < 0.01) and had a significantly (320 percent) increased rigidity (p < 0.01) and a significantly (60 percent) decreased strain at twenty newtons (p < 0.05). In contrast, the tensile properties of the tendons that had a gap of more than three millimeters did not change significantly with time. Our data indicate that, in a dog model involving sharp transection followed by repair, a gap at the repair site of more than three millimeters does not increase the prevalence of adhesions or impair the range of motion but does prevent the accrual of strength and stiffness that normally occurs with time.

Reconstruction of the flexor pulley. The effect of the tension and source of the graft in an in vitro dog model.

Flexor pulleys in the hindpaw digits of twenty-eight adult mixed-breed dogs were reconstructed in order to investigate the influence, on the reconstruction, of the source of the autogenous tissue (intrasynovial compared with extrasynovial tendon) and the tension applied during the repair. The ipsilateral peroneus longus tendon was used to reconstruct the A2 pulley with an around-the-bone technique in twenty-one digits; the graft was sutured at a tension of 0.49, 0.98, and 1.96 newtons in seven digits each. The flexor digitorum profundus tendon of an adjacent digit was used to reconstruct the A2 pulley, at a tension of 0.98 newton, in seven additional digits. The contralateral digits were used as controls for all twenty-eight treated digits. The digits were tested in a custom apparatus designed to measure the frictional force generated between the reconstructed pulley and the tendon beneath it. The frictional force did not differ significantly (p > 0.5) among the three groups repaired with peroneus longus tendon; however, the average value was more than five times that produced in the contralateral, control digits. The average frictional forces created by the flexor digitorum profundus grafts were similar to those in the contralateral, control digits. Reconstruction with the flexor digitorum profundus at a tension of 0.98 newton produced significantly less frictional force (p < 0.05) than that produced by the peroneus longus graft at the same tension. This in vitro model of reconstruction of the A2 pulley demonstrated that tendon from an intrasynovial source (the flexor digitorum profundus) produced less frictional resistance to gliding of the tendon than did tendon from an extrasynovial source (the peroneus longus). This result is consistent with previously published findings that intrasynovial tendons may make better grafts than extrasynovial tendons for the reconstruction of gliding flexor tendons because of decreased friction and better healing qualities. Intrasynovial tendons may also make better grafts for the reconstruction of flexor pulleys.

Flexor digitorum profundus tendongrafting (intrasynovial donor tendons)

Traditional single- and two-stage tendon grafting methods for flexor tendon reconstruction have been unable toconsistently restore satisfactory digital flexion. Although multiple factors may affect the ultimate outcome, the role of the donor tendon graft has only recently been examined. Current methods of flexor tendon grafting for failed zone II tendon repairs and neglected flexor tendon lacerations involve the use of extrasynovial donor grafts. Clinical and histological studies have shown significant adhesion formation as a result of early cellular necrosis and peritendinous tissue ingrowth into the extrasynovial donor graft. The formation of these adhesions may result in poor tendon excursion and limited proximal interphalangeal joint rotation. Recent studies have shown that intrasynovial donor tendon grafts are incorporated to the native tendon site by a unique intrinsic mechanism of repair. Improved functional characteristics of increased tendon excursion and increased digital rotation are primarily caused by this paucity of adhesion formation and will hopefully result in improved overall patient outcomes.