Preliminary effects of hyaluronic acid on early rehabilitation of patients with isolated anterior cruciate ligament reconstruction

Clinical and Biochemical Implications of Hyaluronic Acid in Musculoskeletal Rehabilitation: A Comprehensive Review

Hyaluronic acid (HA) naturally occurs as a biopolymer in the human body, primarily in connective tissues like joints and skin. Functioning as a vital element of synovial fluid, it lubricates joints, facilitating fluid movement and diminishing bone friction to protect articular well-being. Its distinctive attributes encompass notable viscosity and water retention capacities, ensuring flexibility and absorbing shock during motion. Furthermore, HA has gained significant attention for its potential benefits in various medical applications, including rehabilitation. Ongoing research explores its properties and functions, especially its biomedical applications in several clinical trials, with a focus on its role in improving rehabilitation outcomes. But the clinical and biochemical implications of HA in musculoskeletal rehabilitation have yet to be fully explored. This review thoroughly investigates the properties and functions of HA while highlighting its biomedical applications in different clinical trials, with a special emphasis on its role in rehabilitation. The presented findings provide evidence that HA, as a natural substance, enhances the outcomes of musculoskeletal rehabilitation through its exceptional mechanical and biochemical effects.

Efficacy and Safety of Hyaluronic Acid Intra-articular Injection after Arthroscopic Knee Surgery: A Systematic Review and Meta-analysis

OBJECTIVE

Hyaluronic acid (HA) intra-articular injection after arthroscopic knee surgery has been widely applied but its efficacy and safety remain controversial. The aim of this systematic review is to analyze the efficacy and safety of HA intra-articular injection after arthroscopic knee surgery, and to compare the efficacy of HA with different molecular weights.

METHODS

We conducted a systematic literature search in PubMed, Embase, Google scholar and the Cochrane library from inception to 16 September 2022 for English-written articles, in order to identify randomized controlled trials that evaluated the clinical efficacy and/or safety of HA intra-articular injection after arthroscopic knee surgery. Then we meta-analyzed the outcomes of patients given intra-articular HA injections postoperatively and control patients. We also evaluated the influence of HA with different molecular weights. In every calculation, sensitive analysis was performed. The visual analogue scale (VAS) for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and adverse events were selected as the primary outcome measurements, while Lysholm, International Knee Documentation Committee (IKDC) and Tegner score were selected as the secondary outcome measurements. Publication bias of every outcome was evaluated using egger test.

RESULTS

Fifteen studies involving 951 knees were included and 12 of them were used to performed the meta-analysis. The results showed no significant difference between the HA group and control group according to VAS, whether assessed at less (P = 0.90) or more than 6 months (P = 0.55). Besides, there were no statistical differences between the HA group and control group according to subgroup analysis (Ps = 0.77, 0.91 and 0.81 in anterior cruciate ligament reconstruction, meniscectomy and overall groups, respectively). Compared to control group, the overall effect of WOMAC score showed no significant differences (P = 0.25), nor did in two subgroups (P = 0.37 and P = 0.22). Outcomes measured by Lysholm (P = 0.13), IKDC (P = 0.86) and Tegner (P = 0.42) scores showed no significant differences, either. The analysis of the risk of adverse events indicated no increase in HA groups (P = 0.06). We found no significant differences between high- and low-molecular-weight HA at 6 (P = 0.96) or 12 months (P = 0.93) postoperatively. Two studies failed to pass the sensitive analysis and the reasons were discussed detailly and acceptable publication bias was observed.

CONCLUSIONS

Although HA injection after arthroscopic knee surgery is safe, the available evidence does not support its efficacy in pain relief and functional recovery. Therefore, the application of HA injection after arthroscopic knee surgery is not recommended.

Intraarticular viscosupplementation following arthroscopic anterior cruciate ligament reconstruction: A systematic review

BACKGROUND

Pain, swelling and joint stiffness are the major problems following arthroscopic ACL reconstruction (ACLR) surgery that restrict early return to sports and athletic activities. The patients often receive prolonged analgesic medications to control the inflammatory response and resume the pre-injury activities. This systematic review aims to evaluate the safety and efficacy of intraarticular (IA) hyaluronic acid (HA) injection following ACLR.

MATERIAL AND METHODS

A literature search of electronic databases and a manual search of studies reporting clinical effectiveness of IA HA following ACLR was performed on 1^st November 2020. The quality of the methodology and risk of bias was assessed using the Cochrane Collaboration Risk of Bias Tool and Newcastle-Ottawa scale for randomized-controlled trial and prospective cohort studies, respectively.

RESULTS

Of 324 studies retrieved, four studies (3 RCTs and one prospective cohort study) were found to be suitable for inclusion in this review. These studies had a low to moderate risk of bias. There were 182 patients in the HA group and 121 patients in the control group. The demographic characteristics of the patients were similar in all studies. The pooled analysis of studies evaluating pain at different follow up periods (2-week, 4-6 weeks, 8-12 weeks) after ACLR revealed no significant difference between the HA and control groups (p > 0.05). The knee swelling was significantly less in the HA group at two weeks (MD -7.85, 95% CI: [-15.03, -0.68], p = 0.03, I2 = 0%), but no such difference was noted after 4-6 weeks and 8-12 weeks. The functional outcome score was not significantly different between the groups (SMD 0.00, 95% CI: 0.38 to 0.38, p = 0.99, I² = 0%).

CONCLUSIONS

Although the individual study demonstrated a short-term positive response regarding pain control and swelling reduction, the pooled analysis did not find any clinical benefit of IA HA injection following ACLR surgery.

LEVEL OF EVIDENCE

II.

The efficacy of intraarticular viscosupplementation after arthroscopic partial meniscectomy: a randomized controlled trial

BACKGROUND

This study aimed to evaluate the efficacy of viscosupplementation after arthroscopic partial meniscectomy.

METHOD

A randomized controlled trial of 47 patients who underwent arthroscopic partial meniscectomy was conducted between March 2020 and March 2021. Patients were randomized into two groups: a viscosupplementation group (n = 23) and a control group (n = 24). A single-dose intraarticular hyaluronic acid injection was used as viscosupplementation. The 100 mm visual analogue scale (VAS) for pain assessment was measured at baseline and at 1 day, 2 weeks, 6 weeks, and 3 months post-surgery. The International Knee Documentation Committee (IKDC), Tegner, Lysholm, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores and range of motion (ROM) of the knee were measured at baseline, 2 weeks, 6 weeks, and 3 months.

RESULTS

The 100 mm VAS score for pain was significantly lower in the viscosupplementation group at 2 weeks post-surgery (27.5 mm vs. 40.7 mm, P = 0.047). ROM was significantly greater in the viscosupplementation group than in the control group at 2 weeks (131.5° vs. 121.0°, P = 0.044) post-surgery. No significant differences were observed in the IKDC or in the Tegner, Lysholm, and WOMAC scores between the two groups.

CONCLUSIONS

Viscosupplementation after arthroscopic partial meniscectomy significantly reduced pain at 2 weeks post-surgery and improved ROM of the knee at 2 weeks post-surgery. There might be some benefits in terms of pain and functional recovery of viscosupplementation after arthroscopic surgery.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

TRIAL REGISTRATION

This randomized controlled trial was registered at cris.nih.go.kr # KCT0004921 .

Prevention of post-traumatic osteoarthritis after intra-articular knee fractures using hyaluronic acid: a randomized prospective pilot study

PURPOSE

Based on the irreversible destruction of hyaline cartilage, post-traumatic osteoarthritis (PTOA) is a notorious sequelae after intra-articular knee fractures. This study evaluates the clinical efficacy and applicability of immediate post-operative intra-articular injection of hyaluronic acid (IA HA) into the knee joint with an intra-articular fracture.

METHODS

Prospective randomized case-control study involving 40 patients (20 in each group) with intra-articular knee fracture with an average follow-up of 23 months (range 18-24 months). Twenty patients with intra-articular distal femoral or intra-articular proximal tibial fractures who met our inclusion criteria received three intra-articular hyaluronic acid injections weekly starting immediately after ORIF. Another 20 patients serving as a control group received no injection after ORIF. Patients were assessed functionally with Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) score. Plain X-rays and when indicated CT scans were used to assess radiological union.

RESULTS

The results showed patients treated with intra-articular hyaluronic acid injection after fixation had significantly less pain (KOOS) (p = 0.01). No significant difference was found between both groups in other KOOS-related outcome measures, complications, functional outcome, or quality of life.

CONCLUSIONS

These preliminary results support a direct role for hyaluronic acid in the acute phase of the inflammatory process that follows articular injury and provides initial evidence for the efficacy of IA HA.

No Effects of Early Viscosupplementation After Arthroscopic Partial Meniscectomy: A Randomized Controlled Trial

BACKGROUND

The management of the postoperative period after knee arthroscopic surgery may be challenging because surgical trauma deeply alters the joint microenvironment, causing the release of several catabolic molecules and proinflammatory factors that might slow down functional recovery. The possibility of using hyaluronic acid (HA) to promote postoperative pain relief and expedite functional improvement seems attractive, considering its biological properties.

PURPOSE

The aim of the present double-blind randomized controlled trial was to evaluate the effects, in terms of pain control and functional recovery, provided by a single HA injection performed at the end of arthroscopic meniscectomy.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 90 patients, 18 to 55 years old, were included according to the following criteria: (1) chronic, symptomatic meniscal tears requiring partial resection; (2) a healthy contralateral knee; (3) no previous surgery on the index knee; and (4) no other concurrent articular lesions requiring surgical treatment (eg, cartilage or ligament injuries). Patients were randomized into 2 treatment groups: one underwent meniscectomy alone, whereas the other also received an injection of 3 mL HA at the end of the procedure. All patients were evaluated at baseline and then at 15, 30, 60, and 180 days using the following tools: International Knee Documentation Committee (IKDC) subjective, Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) for pain, VAS for general health status, and Tegner scores. The transpatellar circumference and active and passive ranges of motion were also recorded during the follow-up evaluations.

RESULTS

No major adverse events were reported using HA postoperatively. A statistically significant increase in all the clinical scores was reported in both treatment groups, but no significant intergroup difference was documented at any follow-up evaluation. No difference was observed also in the objective measurements. The mean time to return to full sports activity was not different between groups, and a comparable satisfaction rate was recorded in both treatment groups.

CONCLUSION

Early postoperative viscosupplementation did not provide significant clinical benefits after arthroscopic meniscectomy. Despite the lack of major adverse events, the administration of a single HA injection at the end of the surgical procedure is not a successful strategy to provide either faster functional recovery or symptomatic improvement after meniscectomy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02629380.

Early Viscosupplementation After Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

BACKGROUND

Hyaluronic acid (HA) has been widely used to treat osteoarthritis given its biological and mechanical properties. Because HA is an "intra-articular" treatment approach that affects the joints, it could be used in the management of acute conditions, such as during the early postsurgical phase, to reduce inflammatory stress and improve articular function.

PURPOSE

The aim of the present double-blind, randomized controlled trial was to evaluate pain control and functional recovery provided by a single injection of HA performed the day after anterior cruciate ligament (ACL) reconstruction.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

The study enrolled 60 patients affected by primary, chronic, and symptomatic ACL tear requiring surgical reconstruction. All patients were treated with the same reconstructive technique and rehabilitation protocol. Exclusion criteria were (1) concurrent articular lesion requiring surgical treatment, (2) axial malalignment in the index limb, and (3) functional limitation or pain in the contralateral knee. The day after the procedure, the patients were randomized to receive a single injection of 3 mL HA or 3 mL saline solution after surgical drains were removed. All patients were evaluated at baseline and at 15, 30, 60, and 180 days and 12 months after surgery by use of the following tools: Short Form-36 Health Survey (SF-36), International Knee Documentation Committee (IKDC) subjective score, visual analog scale (VAS) for pain, VAS for general health status, and Tegner score. At each follow-up evaluation, the transpatellar circumference and active and passive range of motion (ROM) of both knees were recorded.

RESULTS

No severe adverse events were documented after early viscosupplementation. A significant improvement was documented in both treatment groups. Significant differences were documented in the transpatellar circumference at 60 days and in active ROM at 30 days postoperatively; patients who received HA had better values compared with the placebo group (P = .022 and .027, respectively). No statistically relevant intergroup differences were found in the clinical scores.

CONCLUSION

The study documented no adverse events and had some positive findings in terms of active ROM recovery and transpatellar circumference reduction. However, the early postoperative application of viscosupplementation did not lead to significant improvement in clinical scores after ACL reconstruction.

REGISTRATION

NCT02630407 (ClinicalTrials.gov identifier).

Systematic Review of Biological Modulation of Healing in Anterior Cruciate Ligament Reconstruction

Background:

Whether biological modulation is effective to promote healing in anterior cruciate ligament (ACL) reconstruction remains unclear.

Purpose:

To perform a systematic review of both clinical and experimental evidence of preclinical animal studies on biological modulation to promote healing in ACL reconstruction.

Study Design:

Systematic review; Level of evidence, 2.

Methods:

A systematic search was performed using the PubMed, Ovid, and Scopus search engines. Inclusion criteria were clinical and animal studies involving subjects with ACL injury with the use of biological modulation to promote healing outcomes. Methodological quality of clinical studies was evaluated using the Critical Appraisal Skill Programme (CASP) appraisal tool, and animal studies were evaluated by a scoring system based on a published checklist of good animal studies.

Results:

Ten clinical studies and 50 animal studies were included. Twenty-five included studies were regarded as good quality, with a methodological score ≥5. These studies suggested that transforming growth factor–beta (TGF-β), mesenchymal stem cells, osteogenic factors, and modalities that reduce local inflammation may be beneficial to promote graft healing in ACL reconstruction.

Conclusion:

This systematic review suggests that biological modulation is able to promote healing on top of surgical treatment for ACL injuries. This treatment strategy chiefly works through promotion of healing at the tunnel-graft interface, but the integrity of the intra-articular midsubstance of the graft would be another target for biological modulation.

The role of viscosupplementation

The treatment of early osteoarthritis in middle-aged athletes with intra-articular (IA) viscosupplementation using hyaluronic acid (HA) has been used since the late 1980s. Administration of IA HA has demonstrated anti-inflammatory, anabolic, and analgesic effects. Treatment of acute injuries such as anterior cruciate ligament reconstruction and full thickness chondral lesions have benefited with the addition of IA HA. Use of IA HA has also been shown to delay total knee arthroplasty. Although IA HA has shown significant benefits in the middle-aged athletes, it is not a ubiquitous treatment option. Success with corticosteroid injections can be used as a clinical marker for subsequent success with HA injections.

Rehabilitation after anterior cruciate ligament reconstruction: a systematic review

BACKGROUND

Rigorous rehabilitation after anterior cruciate ligament (ACL) reconstruction is necessary for a successful surgical outcome. A large number of clinical trials continue to assess aspects of this rehabilitation process. Prior systematic reviews evaluated fifty-four Level-I and II clinical trials published through 2005.

METHODS

Eighty-five articles from 2006 to 2010 were identified utilizing multiple search engines. Twenty-nine Level-I or II studies met inclusion criteria and were evaluated with use of the CONSORT (Consolidated Standards of Reporting Trials) criteria. Topics included in this review are postoperative bracing, accelerated strengthening, home-based rehabilitation, proprioception and neuromuscular training, and six miscellaneous topics investigated in single trials.

RESULTS

Bracing following ACL reconstruction remains neither necessary nor beneficial and adds to the cost of the procedure. Early return to sports needs further research. Home-based rehabilitation can be successful. Although neuromuscular interventions are not likely to be harmful to patients, they are also not likely to yield large improvements in outcomes or help patients return to sports faster. Thus, they should not be performed to the exclusion of strengthening and range-of-motion exercises. Vibration training may lead to faster and more complete proprioceptive recovery but further evidence is needed.

CONCLUSIONS

Several new modalities for rehabilitation after ACL reconstruction may be helpful but should not be performed to the exclusion of range-of-motion, strengthening, and functional exercises. Accelerated rehabilitation does not appear to be harmful but further investigation of rehabilitation timing is warranted.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Viscosupplementation with hylan g-f 20 in patients with osteoarthrosis of the knee

Viscosupplementation (VIS) is one of several treatment modalities for osteoarthritis of the knee. It is useful in the treatment of osteoarthritis when other methods of conservative care have failed and it may be a safer method of treatment than oral chemical therapy which can have significant side effects with even short-term usage. The biochemical effects of hyaluronic acid are incompletely understood, however there are several accepted modes of action which result in a positive clinical effect on the function of the knee joint. There is some evidence that hyaluronic acid preparations with a higher molecular weight may be more beneficial to the patient. It is commonly used after arthroscopic meniscectomy and or debridement of the knee in a patient with chondral disease. The clinical effects have been well documented in multiple studies in patients with mild to moderate osteoarthritis in study groups before or after arthroscopic surgery of the knee. Adverse events do occur and are easily treated with only rare case reports of systemic effects. Furthermore, there is some evidence that VIS can prolong the need for total knee arthroplasty in the older patient as well.

Effective lubrication of articular cartilage by an amphiphilic hyaluronic acid derivative

BACKGROUND

Intra-articular injection of hyaluronic acid based therapies is gaining popularity as a treatment option for non-operative management of patients with symptomatic osteoarthritis. Although there is an abundance of evidence for both biological and mechanical mechanisms of joint protection by hyaluronic acid, one clear intention of viscosupplementation is to reduce friction and wear by providing an extrinsic lubricant. We tested the in vitro friction response of a novel hyaluronic acid derivative that presents amphiphilic features to promote adhesion to the cartilage surface and thereby improve cartilage lubrication.

METHODS

Migrating Contact Area and Static Contact Area friction tests were conducted on bovine articular cartilage to assess the efficacy of two lubricants, a chemically modified amphiphilic hyaluronic acid and synovial fluid from a healthy joint, as well as a phosphate buffered saline negative control.

FINDINGS

No differences in lubrication (P=0.34) were evident between the three test articles during the Migrating Contact Area test, which represents articulation of healthy articular cartilage. The modified hyaluronic acid presented an equilibrium friction coefficient 2.8 times less than that of the synovial fluid (P ≤ 0.0005) and five times less than that of the PBS control (P ≤ 0.0001) during the Static Contact Area test, representing a mixed lubrication condition.

INTERPRETATION

The present study demonstrated that a chemically modified amphiphilic hyaluronic acid can provide equivalent lubrication to synovial fluid during articulation of loaded healthy articular cartilage and can provide superior lubrication as indicated by a lower coefficient of friction than synovial fluid under loading conditions potentially associated with cartilage wear.

Viscosupplementation with hyaluronic acid in the treatment for cartilage lesions: a review of current evidence and future directions

Diseases involving the articular cartilage are one of the leading causes of physical impairment among the adult population. While surgical technique and advancement have allowed us effective means at treating these diseases, this is not without significant risk and morbidity. With a very solid safety profile, viscosupplementation with hyaluronic acid (HA) derivatives has become an excellent modality for treating diseased articular cartilage. Recent literature supports the use of HA not only in the management of the pain associated with osteoarthritis but also as a disease-modifying agent as well. Further studies have started to define exciting new roles for viscosupplementation in the treatment for acute injuries to the joint microenvironment.

Long term safety, efficacy, and patient acceptability of hyaluronic acid injection in patients with painful osteoarthritis of the knee

The increasing prevalence of painful knee osteoarthritis has created an additional demand for pharmacologic management to prevent or delay surgical management. Viscosupplementation, via intraarticular injection of hyaluronic acid (HA), aims to restore the favorable milieu present in the nonarthritic joint. The safety profile of intraarticular HA injections for painful knee osteoarthritis is well established, with the most common adverse effect being a self-limited reaction at the injection site. Although acceptance of the early literature has been limited by publication bias and poor study quality, more recent and rigorous meta-analysis suggests that intraarticular HA injection is superior to placebo injection for pain relief and matches, if not surpasses, the effect size of other nonoperative treatments, such as nonsteroidal anti-inflammatory medication. Intraarticular HA injection is effective in providing temporary pain relief in patients with painful knee osteoarthritis. Future investigations should focus on optimizing the composition and administration of HA agents to provide prolonged relief of painful osteoarthritis in the knee and other joints.

Intra-articular hyaluronic acid: potential treatment of younger patients with knee injury and/or post-traumatic arthritis

Anterior cruciate ligament (ACL) and meniscal injuries are common in both athletes and the general population. Such injuries may lead to early-onset post-traumatic osteoarthritis (OA) in 50% to 60% of patients, regardless of whether patients had reconstruction performed. In younger patients, intra-articular (IA) injection of hyaluronic acid (HA) may be useful for improving short-term outcomes and possibly slowing or arresting the progression of OA. Hyaluronic acid has anti-inflammatory, anabolic, and chondroprotective effects, which have been demonstrated in in vitro and animal models of meniscal and ACL injury. Results from several clinical trials and patient series have demonstrated the benefit of IA HA injection in younger patients with acute knee damage, including symptomatic meniscal tears and isolated ACL injury with chondral injury, although evidence for this is less extensive than the large database supporting the use of IA HA injection in older patients with knee OA. Administration of HA has been shown to improve outcomes in patients undergoing knee arthroscopy, and IA HA also has direct antinociceptive effects that may contribute to its benefit in patients with patellofemoral pain. However, the use of IA HA in patients with ACL injury or early OA has been evaluated in only a few studies. Thus, there is a need for larger-scale randomized controlled trials with longer durations of follow-up to provide more definitive evaluation of the efficacy and safety of IA HA in these patients. Such studies provide an opportunity to further elucidate the benefits of IA HA in younger patients with knee damage and may result in appropriate expansion of use in this large population, which has a substantial need for new treatment alternatives.

The effects of applying adhesion prevention gel on the range of motion and pain after TKA

A mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HA/CMC) has been shown to be effective for decreasing postoperative adhesions in various kinds of surgeries. We evaluated the clinical efficacy and safety of HA/CMC gel on the early postoperative range of motion and pain relief after total knee arthroplasty (TKA). Thirty one patients who underwent bilateral TKA as a single-stage procedure for primary osteoarthritis were included in the study. At the completion of surgery, among both knees, the HA/CMC gel was applied to one knee (the HA/CMC group) and HA/CMC gel was not applied to the other knee (the control group). The primary outcome measure was the early assessment of range of motion and the secondary outcome measures were the VAS pain scores and the number of complications in each group. Periarticular application of HA/CMC gel was safe without causing any wound problems or infection. However, local application of HA/CMC gel neither increased the range of motion nor reduced the pain during the early postoperative period of TKA.

Effects of supplemental intra-articular lubricin and hyaluronic acid on the progression of posttraumatic arthritis in the anterior cruciate ligament-deficient rat knee

BACKGROUND

Lubricin and hyaluronic acid lubricate articular cartilage and prevent wear. Because lubricin loss occurs after anterior cruciate ligament injury, intra-articular lubricin injections may reduce cartilage damage in the anterior cruciate ligament-deficient knee.

PURPOSE

This study was conducted to determine if lubricin and/or hyaluronic acid supplementation will reduce cartilage damage in the anterior cruciate ligament-deficient knee.

STUDY DESIGN

Controlled laboratory study.

METHODS

Thirty-six male rats, 3 months old, underwent unilateral anterior cruciate ligament transection. They were randomized to 4 treatments: (1) saline (phosphate-buffered saline [PBS]), (2) hyaluronic acid (HA), (3) purified human lubricin (LUB), and (4) LUB and HA (LUB+HA). Intra-articular injections were given twice weekly for 4 weeks starting 1 week after surgery. Knees were harvested 1 week after the final injection. Radiographs of each limb and synovial fluid lavages were obtained at harvest. Histologic analysis was performed to assess cartilage damage using safranin O/fast green staining. Radiographs were scored for the severity of joint degeneration using the modified Kellgren-Lawrence scale. Synovial fluid levels of sulfated glycosaminoglycan, collagen II breakdown, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and lubricin were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Treatment with LUB or LUB+HA significantly decreased radiographic and histologic scores of cartilage damage (P = .039 and P = .015, respectively) when compared with the PBS and HA conditions. There was no evidence of an effect of HA nor was the LUB effect HA-dependent, suggesting that the addition of HA did not further reduce damage. The synovial fluid of knees treated with LUB had significantly more lubricin in the synovial fluid at euthanasia, although there were no differences in the other cartilage metabolism biomarkers.

CONCLUSION

Supplemental intra-articular LUB reduced cartilage damage in the anterior cruciate ligament-transected rat knee 6 weeks after injury, while treatment with HA did not.

CLINICAL RELEVANCE

Although longer term studies are needed, intra-articular supplementation (tribosupplementation) with lubricin after anterior cruciate ligament injury may protect the articular cartilage in the anterior cruciate ligament-injured knee.

The use of hyaluronan after arthroscopic surgery of the knee

Viscosupplementation is defined as the use of intra-articular hyaluronan therapy for symptomatic osteoarthritis (OA). Originally used for the treatment of ophthalmic disorders, viscosupplementation has been available for over a decade in the United States for the treatment of pain secondary to OA of the knee in patients who have not responded adequately to conservative oral pharmaceuticals including nonsteroidal anti-inflammatories and simple analgesics. The majority of patients with symptomatic knee OA will have evidence of meniscal and/or articular surface pathology, and most orthopaedic surgeons include arthroscopic surgery as a possible treatment modality for the symptomatic patient. Although arthroscopic meniscectomy is the most commonly performed orthopaedic procedure in the United States, in patients with concomitant OA, disease-related pain can persist after arthroscopic surgery. This article reviews some of the more recent evidence recommending the use of viscosupplementation for the management of symptomatic knee OA and pain relief after arthroscopy.

Joint injury and osteoarthritis: soluble mediators in the course and treatment of cartilage pathology

Osteoarthritis is a disabling disease of the aging generation, which results in loss of quality of life and increased healthcare costs. Cytokines appear to play an important role in the cartilaginous degeneration characterizing the pathological process. Increasing experience is being gained with cytokine-modulating therapies aimed at interfering with effects of chondrodegradative cytokines in the synovial fluid. Although in vitro and in vivo effectiveness of several of these therapies has been demonstrated, clinical effectiveness remains disputable, which may be related to the low levels of inflammatory cytokines found in osteoarthritic joints. By contrast, directly after joint trauma, which has been shown to predipose to early osteoarthritis, synovial fluid cytokine levels are strongly increased. Cytokine-modulating therapies, however, have hardly been considered for this indication. Increased knowledge of intra-articular soluble mediators correlating with cartilage pathology will lead to further development of cytokine-modulating products and, eventually, to effective inhibition of cartilage degeneration, in both the osteoarthritic as well as injured joints.