Histological and structural study of the adhesive tissue in knee fibroarthrosis: a clinical-pathological correlation

Prevention of knee stiffness following ligament reconstruction: Understanding the role of Arthrogenic Muscle Inhibition (AMI)

The knee is a joint that is often injured in sport, with a large and increasing number of ligament tears and repairs; postoperative complications can lead to poor outcome, such as stiffness. Beyond the well-known and well-described intra- and extra-articular causes of postoperative stiffness, the present study introduces the concept of a central reflex motor inhibition mechanism called arthrogenic muscle inhibition (AMI). AMI occurs after trauma and can be defined as active knee extension deficit due to central impairment of Vastus Medialis Obliquus (VMO) contraction, often associated with spinal reflex hamstring contracture. This explains the post-traumatic flexion contracture that is so common after knee sprain. The clinical presentation of AMI is easy to detect in consultation, in 4 grades from simple VMO inhibition to fixed flexion contracture by posterior capsule retraction in chronic cases. After recent anterior cruciate ligament (ACL) tear, more than 55% of patients show AMI, reducible in 80% of cases by simple targeted exercises initiated in consultation. Practically, in patients who have sustained knee sprain, it is essential to screen for this reflex mechanism and assess reducibility, as AMI greatly aggravates the risk of postoperative stiffness. In case of hemarthrosis, we recommend joint aspiration, which provides immediate benefit in terms of pain and motor inhibition. In case of persistent AMI, classical electrostimulation and "cushion crush", as used by all physiotherapists, are ineffective. To reduce the risk of postoperative stiffness, no surgery should be considered until AMI has resolved. LEVEL OF EVIDENCE: expert opinion.

The superior healing capacity of MRL tendons is minimally influenced by the systemic environment of the MRL mouse

Murphy Roths Large mice (MRL) exhibit improved tendon healing and are often described as a "super-healer" strain. The underlying mechanisms that drive the superior healing response of MRL remain a controversial subject. We utilized a tendon transplantation model between MRL and "normal-healer" B6-mice to differentiate between the contribution of MRL's innate tendon and systemic environment to its improved healing capacity. Patellar tendons with a midsubstance punch injury were transplanted back into the same animal (autograft) or into an animal of the other strain (allograft). Findings at 4 weeks showed that the innate MRL tendon environment drives its improved healing capacity as demonstrated by improved stiffness and maximum load in MRL-grafts-in-B6-host-allografts compared to B6-autografts, and higher modulus in MRL-autografts compared to B6-graft-in-MRL-host-allografts. Groups with an MRL component showed an increase in pro-inflammatory cytokines in the 3 days after injury, suggesting an early enhanced inflammatory profile in MRL that ultimately resolves. A preserved range of motion of the knee joint in all MRL animals suggests a systemic "shielding effect" of MRL in regard to joint adhesiveness. Our findings 4-weeks post injury are consistent with previous studies showing tissue-driven improved healing and suggest that the systemic environment contributes to the overall healing process.

Early manipulation under anaesthesia for stiffness following total knee arthroplasty is associated with a greater gain in knee flexion

PURPOSE

This study aimed to identify the risk factors for manipulation under anaesthesia (MUA) following total knee arthroplasty (TKA) and whether performing an 'early' MUA within 3 months leads to a greater improvement in range of motion.

METHODS

Primary TKAs performed between 2013 and 2018 at three tertiary New Zealand hospitals were reviewed with a minimum follow-up of 1 year. Clinical details of patients who underwent MUA were reviewed to identify the knee flexion angle prior to and following MUA. Multivariate analysis identified the risk factors for undergoing MUA and compared flexion angles between 'early' (< 3 months) and 'late' MUA (> 3 months).

RESULTS

A total of 7386 primary TKAs were analysed in which 131 underwent an MUA (1.8%). Patients aged < 65 years were two times more likely to undergo MUA compared to patients aged ≥ 65 years (2.5 versus 1.3%, p < 0.001; adjusted HR = 2.1, p < 0.001). There was no difference in the final flexion angle post-MUA between early and late MUA (104.7° versus 104.1°, p = 0.819). However, patients who underwent early MUA had poorer pre-MUA flexion (72.3° versus 79.6°, p = 0.012), and subsequently had a greater overall gain in flexion compared to those who underwent late MUA (mean gain 33.1° versus 24.3°, p < 0.001).

CONCLUSION

Younger age was the only patient risk factor for MUA. Patients who underwent early MUA had similar post-MUA flexion, but had poorer pre-MUA flexion compared to those who underwent late MUA. Subsequently, a greater overall gain in flexion was achieved in those who underwent early MUA.

LEVEL OF EVIDENCE

III.

Three-dimensional computation of fibre orientation, diameter and branching in segmented image stacks of fibrous networks

Fibre topography of the extracellular matrix governs local mechanical properties and cellular behaviour including migration and gene expression. While quantifying properties of the fibrous network provides valuable data that could be used across a breadth of biomedical disciplines, most available techniques are limited to two dimensions and, therefore, do not fully capture the architecture of three-dimensional (3D) tissue. The currently available 3D techniques have limited accuracy and applicability and many are restricted to a specific imaging modality. To address this need, we developed a novel fibre analysis algorithm capable of determining fibre orientation, fibre diameter and fibre branching on a voxel-wise basis in image stacks with distinct fibre populations. The accuracy of the technique is demonstrated on computer-generated phantom image stacks spanning a range of features and complexities, as well as on two-photon microscopy image stacks of elastic fibres in bovine tendon and dermis. Additionally, we propose a measure of axial spherical variance which can be used to define the degree of fibre alignment in a distribution of 3D orientations. This method provides a useful tool to quantify orientation distributions and variance on image stacks with distinguishable fibres or fibre-like structures.

Arthroscopic Lysis of Adhesions and Anterior Interval Release With Manipulation Under Anesthesia for Severe Post-traumatic Knee Stiffness: A Simple and Reproducible Step-by-Step Guide

Post-traumatic knee stiffness can present after injuries around the knee and surgery. Management is guided by the type of initial injury, amount of range-of-motion loss, time since injury, and cartilage status. Cases refractory to conservative management may conventionally be treated with manipulation under anesthesia (MUA), arthroscopic lysis of adhesions, or open quadricepsplasty. We describe our arthroscopic technique of lysis of adhesions with anterior interval release and intraoperative MUA, which has been shown to provide sustainable range-of-motion improvement in a subset of patients with severe knee arthrofibrosis. Although technically demanding, this technique benefits from being minimally invasive, allows for direct visualization of intra-articular structures, and allows all-round arthroscopic release of adhesions to improve patellar mobility and decrease the risk of fracture prior to MUA. A rigorous postoperative formal physical therapy protocol and patient compliance are imperative to achieve good outcomes.

Manipulation under anesthesia following total knee arthroplasty: a comprehensive review of literature

INTRODUCTION

The etiology of the stiff knee after total knee arthroplasty (TKA) is largely unknown, although excessive scar tissue due to arthrofibrosis is an important reason for a limited range of motion (ROM) after this procedure. Persistent limited ROM after TKA results in poor patient-reported outcomes and is increasingly becoming a more prominent reason for TKA revision surgery.

METHODS

A narrative review of current literature on manipulation under anesthesia (MUA) after TKA analyzing etiology and risk factors for stiffness after TKA, effectiveness of MUA and what is known about rehabilitation after MUA.

RESULTS

Literature describes numerous risk factors for insufficient knee ROM after TKA, but a comprehensive valid risk model is lacking. MUA is an effective treatment option with evidence suggesting better outcomes if performed within the first 3 months after TKA. The wide variety in both the indication and timing for MUA, and the lack of scientific evidence on how to rehabilitate patients after MUA, complicates the interpretation of available literature. This is even more so the case on the reporting of one versus two or more MUAs after TKA.

CONCLUSION

Future comparative trials, preferably with a randomized study design, should be conducted to elude more clear indications for MUA, to give clinical guidance on correct timing for MUA and on how to rehabilitate patients afterward.

Presentation and management of arthrofibrosis of the knee: A case report

STUDY DESIGN

Case report.

BACKGROUND

Arthrofibrosis is a debilitating condition that results in pain, decreased range of motion, and decreased function. Although surgical management of arthrofibrosis has been well described in the literature, rehabilitation of the arthrofibrotic knee is less well described.

CASE DESCRIPTION

A 28-year-old female presented with swelling, pain, and decreased strength, range of motion, patellar mobility, and function following an exploratory arthroscopy of her left knee. After failed conservative management, the patient underwent two additional surgeries to remove scar tissue. Following each surgery, the emphasis was on decreasing inflammation and maintaining patellar mobility while increasing joint range of motion and strength. Therapy progression was determined by the presence or absence of inflammatory signs. The second scar tissue removal surgery resulted in a femoral neuropathy that further complicated the rehabilitation process.

OUTCOMES

At 3-year follow-up, the patient continued to present with decreased range of motion and strength compared to the uninvolved limb, but had returned to a modified running program and reported pain no longer limited her ability to participate in activities of daily living.

DISCUSSION

This case report highlights the importance of recognizing that arthrofibrosis may result following a minor knee surgery and with minimal range of motion loss. Additional complications also may result during arthrofibrosis treatment. Progressing rehabilitation based on the inflammatory response may decrease the likelihood of additional scar tissue formation and potentially improve the outcome for the patient.

Revision surgery for the stiff total knee arthroplasty

AIMS

The aim of this study was to examine the results of revision total knee arthroplasty (TKA) undertaken for stiffness in the absence of sepsis or loosening.

PATIENTS AND METHODS

We present the results of revision surgery for stiff TKA in 48 cases (35 (72.9%) women and 13 (27.1%) men). The mean age at revision surgery was 65.5 years (42 to 83). All surgeries were performed by a single surgeon. Stiffness was defined as an arc of flexion of < 70° or a flexion contracture of > 15°. The changes in the range of movement (ROM) and the Western Ontario and McMasters Osteoarthritis index scores (WOMAC) were recorded.

RESULTS

At a mean follow up of 59.9 months (12 to 272) there was a mean improvement in arc of movement of 45.0°. Mean flexion improved from 54.4° (5° to 100°) to 90° (10° to 125°) (p < 0.05) and the mean flexion contracture decreased from 12.0° (0° to 45°) to 3.5° (0° to 25°) (p < 0.05). The mean WOMAC scores improved for pain, stiffness and function. In patients with extreme stiffness we describe a novel technique, which we have called the 'sloppy' revision. This entails downsizing the polyethylene insert by 4 mm and using a more constrained liner to retain stability.

CONCLUSION

To our knowledge, this is the largest series of revision surgeries for stiffness reported in the literature where infection and loosening have been excluded.

TAKE HOME MESSAGE

Whilst revision surgery is technically demanding, improvements in ROM and outcome can be achieved, particularly when the revision is within two years of the primary surgery. Cite this article: Bone Joint J 2016;98-B:622-7.

Manipulation under anesthesia for post traumatic stiff knee-pearls, pitfalls and risk factors for failure

BACKGROUND

Stiffness is common following fractures around knee. Manipulation under anesthesia (MUA) is the initial noninvasive procedure usually performed for such patients. Though MUA has been extensively evaluated for knee arthroplasty, there is paucity of literature regarding its benefits in trauma cases. The purpose of this study was to define the role of manipulation in post traumatic stiff knees.

METHODS

Hospital inpatient and outpatient records from January 2010 to June 2014 were retrospectively reviewed to identify patients undergoing MUA at our institution. Patients with more than one year follow up and adequate data were included. Clinical and radiographic parameters were analyzed to assess outcomes, complications, effect of timing on flexion gain as well as identify risk factors associated with failure.

RESULTS

Out of 45 patients undergoing manipulation, 41 patients with 48 knees (34 unilateral and 7 bilateral) met inclusion criteria. Thirty six manipulations were successful while 3 were abandoned due to tight tissues and 9 developed complications.Successful MUA resulted in immediate gain of 62.36° of flexion which decreased to 49.86° at 1year. There was statistically significant loss of flexion of 12.5° over a year (p value 0.0013). Arc of motion improved from 48.5° to 106.1° at 1year (p value <0.0001). Significant improvement was also seen in extension and fixed flexion deformity (p value <0.0001). No significant difference could be detected between early (<3 months) and late (>3 months) groups with respect to outcomes (p value 0.883)or complications (p value 0.3193). Failed group had significantly lower pre MUA flexion and pre MUA range of motion (p value 0.003). Univariate analysis showed that extensor mechanism ruptures during injury (p value <0.0001) and knees with Flexion <40° (p value 0.0022) or ROM<30° (p value 0.0002) were significantly associated with failures.

CONCLUSION

MUA is a suitable non invasive treatment option for post traumatic stiffness. There is no effect of timing on outcome and late manipulation also results in good outcome. Extensor mechanism rupture and pre manipulation ROM<30° or flexion <40° are associated with failure and such cases should be considered for alternative options for better outcome.

Manipulation under Anesthesia for Stiffness after Total Knee Arthroplasty

PURPOSE

This study evaluated the incidence of manipulation under anesthesia (MUA) for stiffness after total knee arthroplasty (TKA) and the degree of joint motion recovery after MUA.

MATERIALS AND METHODS

A total of 4,449 TKAs (2,973 patients) were performed between March 2000 and August 2014. Cases that underwent MUA for stiffness after TKA were reviewed. TKAs were performed using the conventional procedure in 329 cases and using the minimally invasive procedure in 4,120 cases. The preoperative range of joint motion, timing of manipulation, diagnosis and the range of joint motion before and after MUA were retrospectively investigated.

RESULTS

MUA was carried out in 22 cases (16 patients), resulting in the incidence of 0.5%. The incidence after the conventional procedure was 1.2% and 0.4% after the minimally invasive procedure. In the manipulated knees, the preoperative range of motion (ROM) was 102.5°±26.7°, and the preoperative diagnosis was osteoarthritis in 19 cases, rheumatoid arthritis in two, and infection sequela in one. MUA was performed 4.7±3.0 weeks after TKA. The average ROM was 64.5°±13.5° before manipulation. At an average of 64.3±41.3 months after manipulation, the ROM was recovered to 113.4°±31.2°, which was an additional 49.9° improvement in flexion.

CONCLUSIONS

The satisfactory recovery of joint movement was achieved when MUA for stiffness was performed relatively early after TKA.

Post-traumatic knee stiffness: surgical techniques

Post-traumatic knee stiffness and loss of range of motion is a common complication of injuries to the knee area. The causes of post-traumatic knee stiffness can be divided into flexion contractures, extension contractures, and combined contractures. Post-traumatic stiffness can be due to the presence of dense intra-articular adhesions and/or fibrotic transformation of peri-articular structures. Various open and arthroscopic surgical treatments are possible. A precise diagnosis and understanding of the pathology is mandatory prior to any surgical treatment. Failure is imminent if all pathologies are not addressed correctly. From a general point of view, a flexion contracture is due to posterior adhesions and/or anterior impingement. On the other hand, extension contractures are due to anterior adhesions and/or posterior impingement. This overview will describe the different modern surgical techniques for treating post-traumatic knee stiffness. Any bony impingements must be treated before soft tissue release is performed. Intra-articular stiff knees with a loss of flexion can be treated by an anterior arthroscopic arthrolysis. Extra-articular pathology causing a flexion contracture can be treated by open or endoscopic quadriceps release. Extension contractures can be treated by arthroscopic or open posterior arthrolysis. Postoperative care (analgesia, rehabilitation) is essential to maintaining the range of motion obtained intra-operatively.

Low-dose irradiation and constrained revision for severe, idiopathic, arthrofibrosis following total knee arthroplasty

Treatment options for arthrofibrosis following total knee arthroplasty include manipulation under anesthesia, open or arthroscopic arthrolysis, and revision surgery to correct identifiable problems. We propose preoperative low-dose irradiation and Constrained Condylar or Rotating-hinge revision for severe, idiopathic arthrofibrosis. Irradiation may decrease fibro-osseous proliferation while constrained implants allow femoral shortening and release of contracted collateral ligaments. Fourteen patients underwent fifteen procedures for a mean overall motion of 46° and flexion contracture of 30°. One patient had worsening range of motion while thirteen patients had 57° mean gain in range of motion (range 5°-90°). Flexion contractures decreased by a mean of 28°. There were no significant complications at a mean follow up of 34 months (range 24 to 74 months).

Effect of Anterior Tibiofemoral Glides on Knee Extension during Gait in Patients with Decreased Range of Motion after Anterior Cruciate Ligament Reconstruction

PURPOSE

The purpose of this preliminary investigation was to evaluate the effect of anterior tibiofemoral glides on maximal knee extension and selected spatiotemporal characteristics during gait in patients with knee extension deficits after anterior cruciate ligament (ACL) reconstruction.

METHODS

Twelve patients with knee-extension deficits after recent ACL reconstructions underwent quantitative gait analyses immediately before and after 10 minutes of repeated anterior tibiofemoral glides on the operative limb, and again after a 10-minute seated rest period.

RESULTS

Maximum knee extension during stance phase of the operative limb significantly increased immediately after the treatment (mean increase: 2.0°±4.1°, 95% CI: 0.6°-3.3°). Maximum knee extension decreased after the 10-minute rest period (mean decrease: 0.9°±1.8°, 95% CI: -0.1°-1.8°), although the decrease was not statistically significant. Small increases in operative limb step length, stride length, and gait speed were observed after the rest period compared to baseline values only.

CONCLUSIONS

A single session of anterior tibiofemoral glides increases maximal knee extension during the stance phase of gait in patients with knee-extension deficits. Increases in knee extension are small and short-lived, however, suggesting that continued activity is required to maintain the observed improvements.

How to treat the stiff total knee arthroplasty?: a systematic review

BACKGROUND

Multiple modalities have been used to treat the stiff TKA, including manipulation under anesthesia (MUA), arthroscopy, and open arthrolysis.

QUESTIONS/PURPOSES

We reviewed the literature to address three questions: (1) How many degrees of ROM will a stiff TKA gain after MUA, arthroscopy, and open arthrolysis? (2) Does the timing of each procedure influence this gain in ROM? (3) What is the number of clinically important complications for each procedure?

METHODS

We performed a PubMed search of English language articles from 1966 to 2008 and identified 20 articles, mostly Level IV studies.

RESULTS

For patients who have arthrofibrosis after TKA, the gains in ROM after MUA and arthroscopy (with or without MUA) are similar. Open arthrolysis seems to have inferior gains in ROM. MUA is more successful in increasing ROM when performed early but still may be effective when performed late. Arthroscopy combined with MUA still is useful 1 year after the index TKA. The numbers of clinically important complications after MUA and arthroscopy (with or without MUA) are similar.

CONCLUSIONS

Stiffness after TKA is a common problem that can be improved with MUA and/or arthroscopic lysis of adhesions with few complications. The low quality of available literature makes it difficult to develop treatment protocols.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Incidence of motion loss of the stifle joint in dogs with naturally occurring cranial cruciate ligament rupture surgically treated with tibial plateau leveling osteotomy: longitudinal clinical study of 412 cases

OBJECTIVE

To report the incidence of loss of stifle extension or flexion and its relationship with clinical lameness after tibial plateau leveling osteotomy (TPLO) for treatment of cranial cruciate ligament (CCL) rupture.

STUDY DESIGN

Longitudinal study.

ANIMALS

Dogs (n=280) with CCL rupture (n=412).

METHODS

TPLO was performed without meniscal release or arthrotomy. Angles of extension and flexion of the stifle were measured by goniometry to determine range of motion. Based upon motion loss, stifles were divided in 3 groups: no loss of extension or flexion (n=322), <10 degrees loss of extension or flexion (n=78), > or =10 degrees loss of extension or flexion (n=12).

RESULTS

Loss of extension or flexion > or =10 degrees was associated with significantly (P=.001) higher clinical lameness scores in comparison with no loss, or loss of extension or flexion <10 degrees. Osteoarthrosis in the cranial femorotibial joint was significantly correlated (P<.005, r(2)=0.55) with loss of extension. Loss of extension > or =10 degrees was less tolerable and less amenable to physical rehabilitation than flexion loss.

CONCLUSIONS

Loss of extension or flexion > or =10 degrees was responsible for higher clinical lameness scores. Osteoarthrosis in the cranial femorotibial joint led to extension loss.

CLINICAL RELEVANCE

Loss of extension or flexion should be assessed in dogs with persistent clinical lameness after TPLO so that early intervention can occur. Our study provides guidelines to define clinically relevant loss of extension or flexion of stifle joint after TPLO.

A modern biomaterial for adhesion prevention

A biomaterial composed of carboxymethylcellulose, poly(ethylene oxide), and calcium can be prepared in a variety of ways to reduce fibrin deposition and adhesion formation. This biomaterial platform can be formulated into a flowable gel with tissue adherence appropriate for use in minimally invasive surgery. The device remains at the site of placement even in gravitationally dependent areas. A peridural formulation was shown in preclinical studies to be safe and effective in reducing adhesions to dura following spinal surgery. A peritoneal formulation used on pelvic organs following peritoneal cavity surgery was also shown to be safe and effective. A clinical feasibility study showed that patients with severe back pain and lower extremity weakness treated with the peridural formulation, applied over their nerve roots following laminectomy or laminotomy, experienced significantly reduced symptoms when compared with surgery-only controls. The peritoneal formulation was shown in two multicenter feasibility studies of women undergoing pelvic surgery to significantly reduce adhesion formation when compared with surgery-only controls. Confirmation of the feasibility studies awaits results from pivotal clinical trials. These formulations were safe, effective, and easy to use. This biomaterial provided a benefit to patients undergoing surgery where postsurgical adhesion formation is a concern.

Arthroscopic treatment of patients with moderate arthrofibrosis after total knee replacement

The purpose of this study was to document the effect of arthroscopic management in patients with knee stiffness after total knee replacement. We present a case series study, in which 32 patients have been treated for moderate arthrofibrosis of the knee after total knee replacement, with the same regimen. We have excluded all cases of stiffness, because of infection, mechanical mal-alignment, loosening of the implants and other obvious reasons of stiffness of the knee, rather than pure arthrofibrosis. All patients first underwent a trial of conservative treatment before going for arthroscopic management. A pain catheter for femoral nerve block was inserted just before anesthesia for post-operative pain management. Arthroscopic arthrolysis of the intra-articular pathology was performed in a standardized technique with release of all fibrous bands in the suprapatellar pouch, reestablishing the medial and lateral gutter, release of the patella, resection of the remaining meniscal tissue or an anterior cyclops, if needed. Intensive physiotherapy and continuous passive motion were to start immediately post-operatively. All the patients were available for the follow up and they were evaluated using the knee society rating system. A total of 25 of the 32 procedures resulted in an improvement of the patients knee score. All the knees operated upon had intra-articular fibrous bands, hypertrophic synovitis and peri-patellar adhesions. A total of eight patients suffered from an anterior cyclops lesion and six patients showed pseudomenicus. In 19 cases a medial and lateral relapse of the patella was performed; only 5 patients got an isolated lateral release. The mean knee flexion was 119 degrees (100-130) at the end of arthroscopy and was 97 degrees (75-115) at the last follow up. The eight patients with extension lags decreased from 27 degrees (10 degrees-35 degrees) pre-operatively to 4 degrees (0-10) at time of follow up. The average knee society ratings increased from 70 points prior to the arthroscopy to 86 at time of follow up, which was found to be statistically significant (P < 0.01, student's t test). The average function score also showed improvement from 68 points pre-operatively to 85 at the time of final follow up. The average pain scores improved from 30 points pre-operatively to 41 at the time of final follow up. Our results showed that arthroscopic management of knee stiffness following total knee replacement is a safe and efficient method of treatment. Pain and functional knee scores can improve markedly.

Alpha-smooth muscle actin containing contractile fibroblastic cells in human knee arthrofibrosis tissue. Winner of the AGA-DonJoy Award 2003

INTRODUCTION

Primary arthrofibrosis is of major concern after joint trauma or knee ligament surgery. The underlying mechanism in detail remains unclear. Highly differentiated fibroblastic cells, so-called myofibroblasts, express the actin isoform alpha-smooth muscle actin (ASMA) and have been found to play a major role in tissue contraction during wound healing and organ fibrosis. We therefore studied the expression of myofibroblasts in human primary knee arthrofibrosis tissue.

MATERIALS AND METHODS

Tissue samples were taken from the infrapatellar fat pad and intercondylar region of nine patients who underwent revision surgery due to arthrofibrosis after anterior cruciate ligament (ACL) reconstruction (study group). Control tissue was taken from five patients who underwent primary ACL reconstruction (control group I) and from eight patients, who underwent second-look arthroscopy after primary ACL reconstruction (control group II). ASMA containing fibroblasts were immunostained with a monoclonal antibody. Histomorphometry was performed for total cell amount, ASMA containing fibroblasts, and vessel cross-sections.

RESULTS

The arthrofibrosis group showed a tenfold higher amount of ASMA containing myofibroblasts (23.4% vs. 2.3%) than in control group I. There was a significantly higher total cell count and lower vessel density than in control group I. Control group II showed an upregulation of myofibroblasts almost five times that in control group I; nevertheless there was no evidence of scar formation or tissue fibrosis.

CONCLUSIONS

Myofibroblasts are responsible for scar tissue contraction during wound healing. In arthrofibrosis tissue fibroblast contraction may be involved in tissue fibrosis and contraction with consecutive loss of motion. We found that myofibroblasts are upregulated in arthrofibrosis tissue. ACL reconstruction itself caused an up regulation of myofibroblast content. Nevertheless these patients did not show any clinical or histological signs of arthrofibrosis. Thus it is reasonable to assume that the ratio of myofibroblasts and total cell amount in connective tissue are responsible for the onset of arthrofibrosis. Address the expression of this highly differentiated cell type may therefore present a target for future therapeutic interventions.

Management of knee pain and stiffness after total knee arthroplasty

This article reviews 33 patients who presented with persistent pain, inadequate knee motion, or both after total knee arthroplasty. Of 33 patients, 26 had inadequate motion treated by closed manipulation, arthroscopic manipulation, or a modified open release manipulation. In 23 patients, these procedures were successful. Of the 26 patients, 85% had a history of previous knee surgery or diabetes mellitus. The average gain in range of motion was not different in comparing early (<12 weeks) manipulation versus late (>12 weeks) manipulation. Seven of the 33 patients presenting with pain, swelling, inadequate motion, or snapping sensations had either failure of bonding between the polymethyl methacrylate and the components (4 patients) or painful fibrous intra-articular bands (3 patients). These patients were treated successfully either by recementing the components or by arthroscopic fibrous band release.

Endoscopic quadricepsplasty: A new surgical technique

We present a new surgical subperiosteal endoscopic technique for the release of fibrosis of the quadriceps to the femur caused by gunshot injuries, postsurgical scarring, and fractures, that was developed at the Arthroscopy Group at Hospital Hermanos Ameijeiras in Havana, Cuba. The technique used is a proximal endoscopic subperiosteal extension of the usual arthroscopic intra-articular release of adhesions, using periosteal elevators and arthroscopic scissors placed through medial and lateral superior knee portals to release adhesions and bands of scar tissue beneath the quadriceps mechanism. The technique was used in a prospective case series of 26 male patients aged 19 to 22 years between February 1997 and March 1998 who presented with clinically and ultrasonically documented extra-articular fibrosis resulting in ankylosis of the knee in extension. Only patients who had reached a plateau in their aggressive physiotherapy program with no further progression in knee flexion for 3 months were selected. Those with joint instability, motion-limiting articular surface pathology, and muscle or neurologic injury were excluded. All patients had obtained satisfactory results at 2-year follow-up. The extra-articular release gained at final follow-up was between 30 degrees and 90 degrees of flexion in addition to that obtained at the completion of the standard intra-articular release. Complications included 1 case of deep vein thrombosis, 2 cases of scrotal edema, 5 cases of hemarthrosis, and 2 cases of reflex sympathetic dystrophy. We have found this technique useful in obtaining additional flexion and improved function in a difficult class of patients with ankylosis caused by extra-articular fibrosis of the quadriceps to the femur, allowing immediate aggressive rehabilitation and presenting a useful outpatient alternative with fewer and less severe complications than described with the classic open Thompson's quadricepsplasty.