Comparison of Clinical and Biomechanical Outcomes between Partial Fibulectomy and Drug Conservative Treatment for Medial Knee Osteoarthritis.

BACKGROUND: Upper partial fibulectomy has been preliminarily proved to have the efficacy for pain alleviation and improvement of function in patients with mild to moderate medial compartment knee osteoarthritis (KOA). However, the previous studies lack the control group with other treatments. The aim of this prospective, randomized controlled study is to compare the clinical and biomechanical effects between upper partial fibulectomy and drug conservative treatment on improvement of clinical pain, function, and gait for patients with mild to moderate medial knee osteoarthritis (KOA) and further discuss its biomechanical mechanism. METHODS: From August 2016 to February 2017, 49 and 48 patients with mild to moderate medial KOA were allocated to fibulectomy and drug groups. We assessed the patients' visual analog scale (VAS) pain score, Hospital for Special Surgery (HSS) knee score, limb alignment, passive flexion/extension range of motion (ROM) of the knee, and 3D gait kinematics and kinetics parameters before and after intervention. Repeated-measures ANOVA with Dunnett's post hoc assessment and multivariate analysis of variance were applied for intragroup and intergroup comparisons, respectively. RESULTS: The improvement in the fibulectomy group on the VAS pain score, HSS knee score, walking speed, and walking knee range of motion (ROM) was statistically better than that in the drug group. The decreased overall peak knee adduction moment (KAM) (decreased by 16.1%) and hip-knee-ankle (HKA) angle (decreased by 0.99° from a more varus alignment to a more neutral alignment) of the affected and operated side 1 year after surgery were observed in the fibulectomy group. CONCLUSION: This research demonstrated that as a biomechanical intervention, upper partial fibulectomy can be a better choice in pain relief and function and gait improvement than drug conservative treatment for patients with early-stage knee OA. The long-term clinical outcomes, indication, and rationale for the improvement in clinical symptoms should be investigated further.

Skeletal ligament healing using the recombinant human amelogenin protein.

Injuries to ligaments are common, painful and debilitating, causing joint instability and impaired protective proprioception sensation around the joint. Healing of torn ligaments usually fails to take place, and surgical replacement or reconstruction is required. Previously, we showed that in vivo application of the recombinant human amelogenin protein (rHAM(+)) resulted in enhanced healing of the tooth-supporting tissues. The aim of this study was to evaluate whether amelogenin might also enhance repair of skeletal ligaments. The rat knee medial collateral ligament (MCL) was chosen to prove the concept. Full thickness tear was created and various concentrations of rHAM(+), dissolved in propylene glycol alginate (PGA) carrier, were applied to the transected MCL. 12 weeks after transection, the mechanical properties, structure and composition of transected ligaments treated with 0.5 µg/µl rHAM(+) were similar to the normal un-transected ligaments, and were much stronger, stiffer and organized than control ligaments, treated with PGA only. Furthermore, the proprioceptive free nerve endings, in the 0.5 µg/µl rHAM(+) treated group, were parallel to the collagen fibres similar to their arrangement in normal ligament, while in the control ligaments the free nerve endings were entrapped in the scar tissue at different directions, not parallel to the axis of the force. Four days after transection, treatment with 0.5 µg/µl rHAM(+) increased the amount of cells expressing mesenchymal stem cell markers at the injured site. In conclusion application of rHAM(+) dose dependently induced mechanical, structural and sensory healing of torn skeletal ligament. Initially the process involved recruitment and proliferation of cells expressing mesenchymal stem cell markers.

The effect of platelet-rich plasma on normal soft tissues in the rabbit.

BACKGROUND: Platelet-rich plasma is reported to contain multiple growth factors, and has been utilized in orthopaedic surgery to aid healing in multiple tissues. To date, the use of autologous platelet-rich plasma has not been studied for its effects on normal soft tissue. METHODS: Eighteen adult New Zealand White rabbits were injected with 0.5 mL of autologous platelet-rich plasma in the right or left quadriceps muscle, Achilles tendon, medial collateral ligament, subcutaneous tissue, tibial periosteum, and ankle joint. Saline solution was injected on the contralateral side as a control. The soft tissues were examined histologically at two weeks (six rabbits) and six weeks (six rabbits), and soft tissues from six rabbits that had been reinjected at six weeks were examined at twelve weeks. RESULTS: Inflammatory skin lesions were visible at forty-eight hours at superficial platelet-rich plasma sites. All lesions resolved by six days. Compared with findings in control specimens, histological analysis of platelet-rich plasma injection sites at two weeks showed a marked inflammatory infiltrate with lymphocytic and monocytic predominance. Intra-articular injection showed villous synovial hyperplasia and chronic synovitis. Tendon and ligament sites showed new collagen deposition. Intramuscular injection sites showed thrombosis, necrosis, and calcium deposition. Subcutaneous sites also showed calcium deposition without necrosis as well as collagen nodules representing early scar tissue. Histological examination of platelet-rich plasma injection sites at six and twelve weeks demonstrated a persistent but diminished inflammatory infiltrate. Focal areas of scar tissue were seen with fibroblasts, collagen formation, and neovascularity. All saline solution sites at all times were nonreactive. CONCLUSIONS: Platelet-rich plasma can initiate an inflammatory response in the absence of an inciting injury in normal soft tissue in rabbits.

Pentadecapeptide BPC 157 (PL 14736) improves ligament healing in the rat.

We improved medial collateral ligament (MCL) healing throughout 90 days after surgical transection. We introduced intraperitoneal, per-oral (in drinking water) and topical (thin cream layer) peptide therapy always given alone, without a carrier. Previously, as an effective peptide therapy, stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, an anti-ulcer peptide effective in inflammatory bowel disease therapy (PL 14736)) particularly improved healing of transected tendon and muscle and wound healing effect including the expression of the early growth response 1 (egr-1) gene. After MCL transection BPC 157 was effective in rats when given once daily intraperitoneally (10 microg or 10 ng/kg) or locally as a thin layer (1.0 microg dissolved in distilled water/g commercial neutral cream) at the site of injury, first application 30 min after surgery and the final application 24 h before sacrifice. Likewise, BPC 157 was effective given per-orally (0.16 microg/ml in the drinking water (12 ml/day/rat)) until sacrifice. Commonly, BPC 157 microg-ng-rats exhibited consistent functional, biomechanical, macroscopic and histological healing improvements. Thus, we suggest BPC 157 improved healing of acute ligament injuries in further ligament therapy.

[Effect of platelet derived growth factor BB on healing of medial collateral ligament in rats].

OBJECTIVE: To examine an effect of the locally-used platelet derived growth factor-BB (PDGF-BB) on the healing of the medial collateral ligament (MCL) in the knee joints of rats. METHODS: Forty-eight rats were equally randomly divided into 2 groups: the experimental group (group A) and the control group (group B). MCL of all the rats were ruptured to establish the wound models. In group A, 5 microg of PDGF-BB was locally injected in the wound of each rat and then the wound was sutured; but in group B, the wound was only sutured. After 2 weeks, histological evaluations were performed to determine whether PDGF-BB could promote the healing of MCL. RESULTS: There were significantly more fibroblasts formed during the ligament healing process in group A than in group B (213.44 +/- 15.32 vs. 180.42 +/- 12.78, P < 0.01). The fibroblasts were more mature and more regularly-arranged in group A than in group B. The type, content, and crosslink of the collagen were improved to a greater extent in group A than in group B (P < 0.01). CONCLUSION: PDGF can promote the healing of the injured ligament.

Lack of hormonal influences on mechanical properties of sheep knee ligaments.

BACKGROUND: The number of anterior cruciate ligament injuries in female athletes exceeds that in male athletes at similar competitive levels. This difference has been attributed by some authors to hormone-mediated alteration in knee laxity in women. HYPOTHESIS: Sheep anterior cruciate and medial collateral ligament strength and stiffness are not altered by administration for 6 months of estrogen or a selective estrogen receptor agonist (raloxifene). STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-eight mature ewes were divided into five groups: sham operation (N = 6), ovariectomy (N = 9), ovariectomy and estradiol implant (N = 7), low-dose raloxifene (N = 9), and high-dose raloxifene (N = 7). After 6 months, the animals were sacrificed and ligaments were tested along with those from five rams' knees. RESULTS: No differences were found between treatment groups for maximum force, stiffness, energy to failure, or failure site. The ultimate stress of the rams' anterior cruciate ligaments was significantly higher than that of the ewes. CONCLUSIONS: Estrogen and estrogen receptor agonists at physiologic levels do not lead to decreased knee ligament strength. CLINICAL RELEVANCE: The female hormonal milieu may not be responsible for the increased incidence of anterior cruciate ligament injury in female athletes compared with their male counterparts.

The biomechanical response to doses of TGF-beta 2 in the healing rabbit medial collateral ligament.

Ligament injuries result in significant disability in over 100,000 patients each year. Despite current methods of treatment, 13% of patients with medial collateral ligament (MCL) injury develop early signs of arthritis, suggesting an incomplete return of knee stability. The principal hypothesis of this work was that the addition of TGF-beta 2 to the healing MCL would accelerate the development of scar strength and stiffness. Forty-four rabbits were divided evenly into four groups, with each group receiving either 0.1, 1 or 5 microg of TGF-beta 2 and the fourth group receiving 1 microg TGF-beta 2 and 1 microg of PDGF. Each rabbit underwent bilateral transection of the MCL, with one side having treatment with one of four doses of growth factor and the other side left untreated. All animals were sacrificed at 6 weeks and the structural properties of maximum load at failure, stiffness, and energy absorbed at failure measured. All treatment groups demonstrated an increase in scar mass, but no group had a significant increase in scar load at failure at 6 weeks. The addition of 0.1 microg TGF-beta 2 led to a significant increase in scar stiffness. The addition of PDGF had no significant effect on any of the parameters studied. This study suggests the mechanical stiffness, but not the load at failure, of ligament scar can be significantly altered by the administration of TGF-beta 2.

Exogenous transforming growth factor beta 1 alone does not improve early healing of medial collateral ligament in rabbits.

OBJECTIVE: To determine whether transforming growth factor beta 1 (TGF-beta1) improves early ligament healing. DESIGN: Experimental, controlled study of medial collateral ligaments (MCLs) in rabbits' knees. SETTING: Research laboratory. SUBJECTS: Sixteen skeletally mature, New Zealand White female rabbits. INTERVENTIONS: Ten rabbits had a standardized gap injury made in the MCL of both knees. Three weeks later, a second operation was performed to inject 7 microg of TGF-beta1 in a carrier solution into the right knee MCL, while the left knee MCL was injected with carrier alone. The rabbits were killed 3 weeks after the injection of TGF-beta1 (6 weeks after the original injury). Six of the rabbits (12 knees) had no operation on the MCL and served as external normal controls. OUTCOME MEASURES: Biomechanical measures of the femur-MCL-tibia complex. Histologic evaluation of MCL cell and matrix organization. Transmission electron microscopy measures of MCL fibril diameters. RESULTS: There were no statistically significant differences in the biomechanical measures, fibril diameter distributions and histologic evaluation of the injured MCLs treated with TGF-beta1 or carrier alone. Both groups of injured MCLs were significantly different from normal MCLs. CONCLUSIONS: The results indicate that the dosage and route of delivery of TGF-beta1 did not lead to overt improvement in the healing of the injured MCL. Whether different doses or delivery methods, alone or in combination with TGF-beta1, or other growth factors would lead to improvement remains to be determined.

Collagen expression and biomechanical response to human recombinant transforming growth factor beta (rhTGF-beta2) in the healing rabbit MCL.

We investigated biomechanical and collagen expression in a healing bilateral rabbit medial collateral ligament (MCL) model to human recombinant transforming growth factor beta (rhTGF-beta2) at three and six weeks. Each rabbit had rhTGF-beta2 in a bioabsorbable pellet administered in one side, with the contralateral side serving as control (no rhTGF-beta2). All MCL healed with rhTGF-beta2 producing a profoundly increased scar mass at three weeks which decreased in size toward control at six weeks. In-situ hybridization demonstrated collagen expression (type I and III) no different than control at three weeks, but by six weeks elevated expression of type I was seen. Biomechanical analysis at three weeks showed no effect of rhTGF-beta2 on structural properties. However, at six weeks rhTGF-beta2 significantly inhibited both the maximum load (p < 0.05) and energy absorbed (p < 0.05) with no change in stiffness. Despite increased type I collagen expression and profound increase in early scar mass, rhTGF-beta2 did not improve the structural properties. Whether the dose or mode of delivery is responsible for decline in structural properties cannot be determined in this design. We hypothesize investigations of healing ligaments to cytokines should have biologic and biomechanical properties correlated in the same study at a minimum of two time points.

[The influence of hyaluronic acid and basic fibroblast growth factor on the proliferation of ligamentous cells].

OBJECTIVE: To observe the effects of hyaluronic acid (HA) and basic fibroblast growth factor (bFGF) on the proliferation of the cells from medial collateral ligament (MCL) and anterior cruciate ligament (ACL) cells. METHODS: The MCL cells and ACL cells of mature New Zealand white rabbit were cultured, while HA, bFGF or HA and bFGF were added to the cell culture media, the cellular proliferation was assayed by MTT method. RESULTS: HA only had no effect on the preoliferation of ACL cells, but had a small stimulatory effect on the proliferation of MCL cells. The addition of 1 ng/ml bFGF enhanced the proliferation of both MCL and ACL cells significantly, and this enhancement was maximal in the concentration of 50 ng/ml. However, the enhancement of proliferation of MCL and ACL cells could be achieved when the combination of HA in concentration of 100 micrograms/ml and bFGF in concentration of 100 ng/ml. CONCLUSION: It is evident that bFGF can enhance the proliferation of the ligament cells. HA can maintain the normal growth of ACL cells with no effect on the proliferation of the cells, while HA has a small stimulatory effect on the proliferation of MCL cells. However, when bFGF is coordinated with HA, more improvement of cellular proliferation can be achieved. HA can be used as a potential carrier for bFGF to enhance the healing of ligamentous tissue injuries.

Effect of local application of basic fibroblast growth factor on ligament healing in rabbits.

OBJECTIVE: The effect of basic fibroblast growth factor (bFGF) on healing of a 4-mm defect in the medial collateral ligament of rabbits was studied. METHODS: Fibrin gel containing 0 (vehicle only), 0.1, 1, or 10 micrograms of recombinant human bFGF was applied to the defect during the surgical procedure. Controls did not receive fibrin gel. Four rabbits in each group were sacrificed 1, 2, 3, and 6 weeks after surgery. Repair tissues were subjected to gross and histologic examinations, and expression of type I procollagen messenger RNA was evaluated using in situ hybridization after 2 and 3 weeks. RESULTS: bFGF promoted formation of repair tissue and was associated with early filling of the ligament defect. Tissue maturation was significantly delayed after 3 and 6 weeks in the high-dose bFGF groups. In the low dose group, in contrast, tissue maturation was similar to that in controls at all time points, by both gross and histologic examination. In situ hybridization studies showed that type I procollagen mRNA expression was reduced in all bFGF groups. CONCLUSION: Our data demonstrate that a single local application of bFGF promoted early formation of repair tissue in injured medial collateral ligaments. High doses of bFGF reduced repair tissue maturation, suggesting that in clinical uses the dose may play a significant role.

Migration and healing of ligament cells under inflammatory conditions.

It is well documented that the adult human medial collateral ligament has a functional healing response, whereas the anterior cruciate ligament does not. The differential healing responses of the medial collateral and anterior cruciate ligaments could be due to factors caused by different biological conditions and locations in vivo. In addition, different intrinsic properties of the constituent cells of these ligaments may contribute to their different healing abilities. Ligament healing follows an orderly process of hemorrhage, inflammation, proliferation, and remodeling. At the cellular level, healing involves a cell's detachment from and attachment to the matrix adjacent to the wound area, migration, and proliferation. This study sought to investigate whether, during migration, the responses of the medial collateral and anterior cruciate ligament fibroblasts are intrinsically different under the same inflammatory conditions. Human medial collateral and anterior cruciate ligament fibroblast cells were cultured, and in vitro wounds were simulated by streaking the cells with an inoculating loop, creating a cell-free area. The migration of the cells into this gap, thus filling the cell-free area, was observed. Two sets of experiments were conducted; one varied the wound width and the other added the inflammatory factors tumor necrosis factor-alpha, complement C5a, and lipopolysaccharide. As the width of the wound increased, the rate of recovery decreased for both types of ligament cells (slope: anterior cruciate ligament, 0.13 hour/micron and medial collateral ligament, 0.10 hour/micron). Also, the three inflammatory factors used all inhibited the recovery rates of both ligaments to ones that were 1.4-2.3 times slower than controls. However, in both sets of experiments, the anterior cruciate ligament fibroblasts were more sensitive to inflammatory factors, and the medial collateral ligament fibroblasts had faster recovery rates (anterior cruciate ligament, 1.2-3.4 times slower than rates for medial collateral ligament fibroblasts, excluding those under lipopolysaccharide treatment). The results showed that medial collateral and anterior cruciate ligament fibroblasts responded differently under the same inflammatory conditions. This may suggest that these differences in intrinsic properties contribute to their different healing responses and abilities.

Effects of local injection of corticosteroids on the healing of ligaments. A follow-up report.

One hundred and one skeletally mature New Zealand White rabbits were used to study the long-term effects of a single injection of corticosteroid on the biomechanical, histological, and biochemical properties of ligament-healing. Two steroid doses were studied, as previously described. The injections were made into a fascial pocket immediately after transection of the ligament. The animals were killed forty-two and eighty-four days after the injury. In our previous investigation, in which we examined the early (inflammatory and proliferative) phases of ligament-healing, the specimens that had been injected with a dose of steroids equivalent to that given to humans demonstrated significantly inferior biomechanical properties and histological organization relative to controls that had not received an injection. In the current study, we examined the later (remodeling and maturation) phases of ligament-healing and found that the tensile strength (the ultimate stress) of the specimens that had been injected with the steroids returned to a value that was equal to that of the controls that had not received an injection; however, the peak load of the specimens that had been injected with steroids remained inferior to that of the controls. This was accompanied by a lag in the histological maturation.