Biodegradable materials for bone defect repair

Compared with non-degradable materials,biodegradable biomaterials play an increasingly important role in the repairing of severe bone defects,and have attracted extensive attention from researchers.In the treatment of bone defects,scaffolds made of biodegradable materials can provide a crawling bridge for new bone tissue in the gap and a platform for cells and growth factors to play a physiological role,which will eventually be degraded and absorbed in the body and be replaced by the new bone tissue.Traditional biodegradable materials include polymers,ceramics and metals,which have been used in bone defect repairing for many years.Although these materials have more or fewer shortcomings,they are still the cornerstone of our development of a new generation of degradable materials.With the rapid development of modern science and technology,in the 21st century,more and more kinds of new biodegradable materials emerge in endlessly,such as new intelligent micro-nano materials and cell-based products.At the same time,there are many new fabrication technologies of improving biodegradable materials,such as modular fabrication,3D and 4D printing,interface reinforcement and nanotechnology.This review will introduce various kinds of biodegradable materials commonly used in bone defect repairing,especially the newly emerging materials and their fabrication technology in recent years,and look forward to the future research direction,hoping to provide researchers in the field with some inspiration and reference.     

三种移植物关节镜下重建前交叉韧带的临床疗效比较

目的比较分析膝关节镜下自体骨-髌腱-骨（B-PT-B）、同种异体跟腱和LARS（1igament advanced reinforce．mentsystem,LARS）人工韧带重建前交叉韧带（anterior cruciate ligament,ACL）的临床疗效差异。方法从2008年2月-2010年11月,对156例膝关节ACL损伤患者行关节镜下ACL重建术,其中自体骨-髌腱-骨（B-PT-B）组39例,同种异体跟腱组53例,LARS人工韧带组64例。通过一般情况、前抽屉试验、Lachman试验、轴移试验、Lysholm、IKDC膝关节评分进行临床疗效评价。结果所有患者随访12-38个月,平均21个月,术后3、6个月各组膝关节Lysholm、IKDC评分,LARS组明显高于其余2组（P〈O．05）。异体跟腱组与自体B-PT-B组相比,差异无统计学意义（P〉0．05）。术后12月及最后随访时,LARS组略高于其余2组,但3组间差异无统计学意义（P〉0．05）。结论在关节镜下应用3种不同移植物重建前交叉韧带的近期疗效均较为满意,LARS组可在术后早期进行膝关节功能活动近期效果优于自体B-PT-B组和异体跟腱组。对于年轻患者．尤其是运动员ACL损伤。LARS人工韧带是一种理想移植材料。     

Electrosurgery in operative arthroscopy

Electrosurgery is a useful tool in the orthopedic procedures outlined, including lateral release, synovial lesions, and shoulder impingement syndrome. The salient positive characteristic of electrosurgery is the capacity to obtain immediate and thorough hemostasis, thereby allowing the patient to begin a rehabilitative program far sooner than with conventional operative techniques. Less hemarthrosis also lowers the level of postoperative pain and the risk of postoperative infection. By becoming familiar with some of the basics of electrosurgery, including equipment and electrosurgical principles, the surgeon and staff can better utilize electrosurgery and be aware of the potential, yet avoidable, complications. The future appears bright for electrosurgery, with new equipment and procedures being developed, but more research is needed to clarify the long-term effects on tissues involved and the clinical results of patients.     

Complications in ankle arthroscopy

Purpose

To determine the complication rate for ankle arthroscopy.

Methods

A review of a consecutive series of patients undergoing ankle arthroscopy in our hospital between 1987 and 2006 was undertaken. Anterior ankle arthroscopy was performed by means of a 2-portal dorsiflexion method with intermittent soft tissue distraction. Posterior ankle arthroscopy was performed by means of a two-portal hindfoot approach. Complications were registered in a prospective national registration system. Apart from this complication registry, patient records, outpatient charts and operative reports were reviewed. Patients with a complication were asked to visit our hospital for clinical examination and assessment of permanent damage and persisting complaints.

Results

An overall complication rate of 3.5?% in 1,305 procedures was found. Neurological complications (1.9?%) were related to portal placement. Age was a significant risk factor for the occurrence of complications. Most complications were transient and resolved within 6?months. Complications did not lead to functional limitations. Residual complaints did not influence daily activities.

Conclusions

Our complication rate is less than half of what has been reported in literature (3.5 vs 10.3?%). The use of the dorsiflexion method for anterior ankle arthroscopy can prevent a significant number of complications. Posterior ankle arthroscopy by means of a two-portal hindfoot approach is a safe procedure with a complication rate that compares favourably to that of anterior ankle arthroscopy.

Level of evidence

Retrospective prognostic study, Level II.     

Complications in knee arthroscopy

All simple arthroscopic procedures during 1999 through 2001 performed at Baerum community hospital were retrospectively examined. Procedures were excluded when being part of more complex procedures. A total of 876 procedures performed on 785 patients were left for examination. Complications were registered from the patient record and all received a written questionnaire or phone call. The answer was obtained from 97.6%. The overall complications rate was low, giving total of 5.00%. A total of 0.68% of the complications had therapeutic consequences. There were two superficial infections, one thromboembolic event/pulmonary embolus and one reoperation due to scar tissue. Other complications were considered minor, and had none or little consequence for the patient comprising preoperative bradycardial episodes, asthmatic events, subcutaneous infusion of total intravenous anaesthetics (TIVA), instrument breakage and conversion to arthrotomi. Postoperatively registered complications included swelling, haemarthros, portal bleeding and fistulation, temporary sensory loss and longstanding pain. Duration of surgery was the only predicting factor for postoperative complications. Simple arthroscopic surgery is safe and has few serious complications. The use of TIVA or tourniquet does not increase the morbidity or complication rate, and prophylaxis against thromboembolism was not necessary.     

Wrist arthroscopy

Major advancement in arthroscopic equipment and techniques has extended the ability of large joint arthroscopy to be performed in smaller joints. Although wrist arthroscopy is performed in small numbers, the same advantages are afforded as in large joint procedures. It provides important diagnostic information and therapeutic intervention, while avoiding the significant morbidity of open techniques. Patients with mechanical wrist pain are the best candidates for arthroscopy to evaluate ligamentous injuries or triangular fibrocartilage complex injuries. Arthroscopy is also an effective tool in the evaluation and treatment of intra-articular distal radius fractures and is particularly useful in radial styloid fractures. Wrist arthroscopy is a technically demanding procedure. However, it remains a safe and effective method for diagnosis and treatment if performed using a precise technique and if the surgeon has a precise understanding of the anatomy of the wrist.     

Ankle arthroscopy

Ankle arthroscopy is an increasingly useful technique for dealing with a wide range of ankle pathology. Improvements in technique and instrumentation are expanding the range of diagnostic and therapeutic indications for arthroscopy of the ankle. Indications include removal of loose bodies, debridement and drilling of osteochondral defects, relief of anterior tibiotalar impingement, lysis of adhesions and arthrodesis. Reconstruction of lateral ankle instability is currently investigational but may some day be a common procedure. A review of ankle arthroscopy, as well as the currently accepted indications, is presented with a brief review of the literature. The techniques for the most common indications are described. The complications and indications for referral are discussed.     

Operative arthroscopy

In a period of 20 months, over 200 patients (age ranged from high school students to middle-aged persons) with knee injuries were treated by operative arthroscopy. The majority of the injuries were incurred while the patients had been participating in athletic events, either competitive or recreational. Operative arthroscopy offers the advantage of shortened hospital stay, rapid rehabilitation, lack of disfiguring scar, and reduced costs. Patients are followed yearly after the first postoperative year. Improved long-term results from diagnostic and operative arthroscopy, as compared to conventional surgical procedures, are expected. The proof of those expectations will be determined in the next several years as this group of patients requiring partial meniscectomies or procedures for pathologic and degenerative conditions is reevaluated.     

Elbow arthroscopy

Decreased surgical morbidity and rapid recovery time associated with arthroscopic surgery of the elbow justify its preference over more extensive open incisions in selected cases. Not all elbow conditions can be treated arthroscopically, however, and open incisions are still preferred in more extensive problems such as displaced fractures and olecranon impingement syndromes.     

Wrist arthroscopy

Understanding of wrist biomechanics and pathology is enhanced by wrist arthroscopy. The procedure does indeed provide an alternative to arthrotomy in selected situations, greatly decreasing patient morbidity. It is a difficult skill to acquire; however, wrist arthroscopy presents diagnostic and therapeutic benefits that far outweigh this short-lived drawback.     

Elbow arthroscopy

It is only in the last decade that elbow arthroscopy had developed as an alternative method of diagnosing and treating pathology of the elbow. When performed with careful technique and a good understanding of the bony and neurovascular anatomy around the elbow, arthroscopy can benefit a large majority of patients with a very low complication rate. The few series that have been reported have shown significant improvement in 73% to 94% of the patients treated. In most cases, functional recovery is quite rapid in the postoperative period.     

Elbow arthroscopy in stiff elbow

Purpose

The purpose of this study was to evaluate and review the functional outcomes after arthroscopic surgery in post-traumatic and degenerative elbow contractures.

Methods

Between 2004 and 2008, 243 patients with post-traumatic or degenerative elbow stiffness were treated with arthroscopic surgery. A total of 212 patients were reviewed at an average of 58 months follow-up (SD ± 17.3). The patients were divided into two groups: group A with post-traumatic stiffness, and group B with degenerative stiffness. Arthroscopic procedures performed included: synovectomy, debridement of osteophytes, removal of loose bodies, anterior and posterior capsulectomy, radial head excision. Ulnar nerve neurolysis was usually performed. The following data were recorded and analysed: sex, age, paraesthesia, previous surgical treatment and complications. Patient outcome was assessed pre- and post-operatively by a visual analogue scale and by the Mayo Elbow Performance Index (MEPI), which assesses pain, ROM, stability and function.

Results

The total average ROM improved by 33° in group A and 20° in Group B. The MEPI improved from 60 to 81 in group A, and from 65 to 91 in group B.

Conclusions

Arthroscopic surgery in post-traumatic and degenerative elbow contractures can be considered a safe, useful, with a long learning curve procedure that offers important improvement of the ROM decreasing surgical morbidity.

Level of evidence

IV.     

Elbow arthroscopy in acute injuries

Purpose

Arthroscopy of the elbow has become a standard treatment option for many indications. The purpose of this article is to review literature concerning the use of arthroscopy for acute elbow injuries.

Methods

The main medical literature databases were searched for articles on the use of elbow arthroscopy in acute injuries. A total of 13 publications relevant to the topic were included. The Coleman methodology score was used to assess the methods of each article.

Results

All published articles have been case reports or retrospective case series. In fracture treatment, arthroscopy has been used in the treatment of displaced radial head, coronoid and capitellum fractures in adults and displaced radial neck and lateral humeral condyle fractures in children with good results. Endoscopic techniques have been used in distal biceps rupture and medial avulsion of the triceps. And also new techniques have been developed for the treatment of intra-articular soft-tissue lesions like rupture of the radial ulnohumeral ligament complex. One of the 13 studies analyzed was considered of good quality, 5 of moderate quality and all others of poor quality with inconsistent methodology and outcomes.

Conclusion

The range of treatments using elbow arthroscopy in acute injuries is expanding and brings new controversies and challenges. Single reports of arthroscopically treated bony and soft-tissue injuries of the elbow showed satisfactory results. However, further randomized prospective studies are needed to evaluate their safety and efficacy compared with open ‘gold standard’ techniques.

Level of evidence

IV.     

Medial approach in elbow arthroscopy

The author undertook a cadaveric dissection study to confirm the hypothesis that starting with the anterior medial portal in elbow arthroscopy is safer than starting with the anterior radial portal. In six cadaveric elbows, the capsule was distended with saline. Both anterior medial and anterior radial approaches were made with the elbow flexed to 90 degrees. Four and one-half millimeter arthroscopic sheaths were inserted and obturators were then left in place while the saline was drained; expanding polyurethane foam was used to distend the capsule. We allowed the polyurethane foam to harden and then dissected all elbows, with special attention given to exposure of the radial and medial nerve and the brachial artery. The hardened foam allowed for continued capsular distension during these dissections and recreated normal distances from instrument portals to neurovascular bundles. The minimum distance from the path of the arthroscopic sheath to the large neurovascular structures was then measured. The distance from the medial portal to the nearest neurovascular structure (median nerve, brachial artery) averaged 23 mm. The distance from the radial portal to the nearest neurovascular structure (radial nerve) averaged 3 mm. The ulnar nerve averaged a 25 mm clearance from the medial portal. Even when the medial portal was made by an incorrect method, the minimum clearance to the median nerve averaged 11 mm. The most frequently recommended current standard technique for elbow arthroscopy involves beginning with an anterior radial portal. However, the findings in this study suggest that an anterior medial portal is a superior starting point.(ABSTRACT TRUNCATED AT 250 WORDS)     

Current concepts in knee arthroscopy

Arthroscopic methods in the knee are used for diagnostic procedures and offer the surgeon a minimally invasive method for repairing a wide variety of injuries in both the acutely and chronically injured knee. These procedures are most often associated with minimal morbidity and early initiation of rehabilitation, and patients may return to work and their daily living activities at a faster rate than with conventional surgical methods. In the acute knee injury, arthroscopy has proven to be a valuable tool in defining the type and extent of the anterior cruciate ligament injury as well as providing definitive assessment of meniscal pathology. Partial menisectomy is the most commonly performed arthroscopic procedure in the knee, acounting for approximately 41% of the total arthroscopic procedures performed. Rapid advancement of arthroscopic techniques in chronic knee injuries, including patellofemoral disorders, osteochondritis dissecans, arthrofibrosis of the knee, degenerative arthritis and cruciate ligament injuries, has resulted in less surgical morbidity without disrupting uninvolved anatomy.     

Hip arthroscopy in athletes.

The limited data (n = 42) and diverse pathology within this study make statistical analysis difficult, although the observations are still meaningful. Diagnostic arthroscopy has defined elusive causes of disabling hip pain in an athletic population including occult labral and chondral damage and rupture of the ligamentum teres. Operative arthroscopy has been effective in reducing the symptoms associated with many of these forms of pathology. For more evident causes of hip pain, such as loose bodies or impinging osteophytes, arthroscopy offers an excellent alternative to traditional open techniques. This study has defined that many intraarticular disorders initially may go unrecognized. The benefit of earlier diagnosis seems intuitive and may minimize extraneous investigative studies, but there are a few caveats. First, various forms of extraarticular pathology (e.g., muscle strains) far outnumber intraarticular injuries and thus the temptation for an extensive intraarticular work up for every hip injury should be avoided. Second, as mentioned, does earlier diagnosis always mean early intervention? There is much that we may not fully understand regarding the natural history of many of these intraarticular disorders that we are only now learning to diagnose.     

Subtalar arthroscopy techniques

This article outlines the features of subtalar arthroscopy. The joint anatomy, portal placement, and surgical techniquesare described. Indications and complications are discussed. This is a brief overview of subtalar arthroscopy.     

Diagnostic wrist arthroscopy

Wrist arthroscopy has become an essential tool for the hand and upper extremity surgeon. It is useful in diagnosing and/or staging a wide range of conditions of the wrist, including cartilage injury, early arthritis, ligament injury, and triangular fibrocartilage complex tears. It can be of great benefit in evaluating wrist pain of unclear cause when imaging studies fail to elucidate the disease. In the hands of an experienced arthroscopist, it can be a more accurate diagnostic tool than studies such as magnetic resonance imaging or arthrography. The rate of complications is very low if proper attention is paid to details. Familiarity with the equipment, thorough knowledge of the anatomy, and development of a systematic approach are all critically essential for a surgeon performing arthroscopy of the wrist. The surgeon must also know when arthroscopy does not provide sufficient access to the wrist and an arthrotomy should be performed.