Treatment of isolated chondral and osteochondral defects in the knee by autologous matrix-induced chondrogenesis (AMIC)

Purpose

The purpose of this study is to evaluate clinical and radiological outcomes of patients treated with autologous matrix-induced chondrogenesis (AMIC) for full-thickness chondral and osteochondral defects of the femoral condyles and patella.

Method

A retrospective evaluation of clinical and radiographic outcomes of patients treated with AMIC for chondral and osteochondral full-thickness cartilage defects of the knee was performed with a mean follow-up of 28.8 ± 1.5 months (range, 13–51 months).

Results

Significant improvements in clinical outcome scores (IKDC, Lysholm, Tegner, and VAS pain score) were noted. The largest improvements were seen in the osteochondral subgroup (mean age 25.9 years), whereas patients treated for chondral defects in the patellofemoral joint and on the femoral condyles improved less. Patients in all groups were generally satisfied with their results. MRI evaluation showed that tissue filling was present but generally not complete or homogenous.

Conclusions

AMIC is a safe procedure and leads to clinical improvement of symptomatic full-thickness chondral and osteochondral defects and to regenerative defect filling. The value of AMIC relative to other cartilage repair procedures and to the natural course remains undefined.

Level of evidence

Case series, Level IV.     

Matrix-induced autologous chondrocyte implantation versus microfracture in the treatment of cartilage defects of the knee: a 2-year randomised study

Cartilage defects occur in approximately 12% of the population and can result in significant function impairment and reduction in quality of life. Evidence for the variety of surgical treatments available is inconclusive. This study aimed to compare the clinical outcomes of patients with symptomatic cartilage defects treated with matrix-induced autologous chondrocyte implantation (MACI™ or microfracture (MF). Included patients were ≥18 and ≤50 years of age with symptomatic, post-traumatic, single, isolated chondral defects (4–10 cm²) and were randomised to receive MACI™ or MF. Patients were followed up 8–12, 22–26 and 50–54 weeks post-operatively for efficacy and safety evaluation. Outcome measures were the Tegner, Lysholm and ICRS scores. Sixty patients were included in a randomised study (40 MACI™, 20 MF). The difference between baseline and 24 months post-operatively for both treatment groups was significant for the Lysholm, Tegner, patient ICRS and surgeon ICRS scores (all P < 0.0001). However, MACI™ was significantly more effective over time (24 months versus baseline) than MF according to the Lysholm (P = 0.005), Tegner (P = 0.04), ICRS patient (P = 0.03) and ICRS surgeon (P = 0.02) scores. There were no safety issues related to MACI™ or MF during the study. MACI™ is superior to MF in the treatment of articular defects over 2 years. MACI™ and MF are complementary procedures, depending on the size of the defect and symptom recurrence. The MACI™ technique represents a significant advance over both first and second generation chondrocyte-based cartilage repair techniques for surgeons, patients, health care institutions and payers in terms of reproducibility, safety, intraoperative time, surgical simplicity and reduced invasiveness.     

Good clinical results with autologous matrix-induced chondrogenesis (Amic) technique in large knee chondral defects

Purpose

Autologous matrix-induced chondrogenesis (AMIC) is a treatment for focal full-thickness cartilage defects combining microfracturing with an exogenous I/III collagen matrix (Chondro-Gide). The aim of the present study was to determine the 7 years outcomes of patients treated with the AMIC technique for knee chondral defects larger than 2 cm². The hypothesis was that the positive short-term outcomes achieved in the previous series would not deteriorate at a 7-year follow-up.

Methods

Twenty-one patients treated with the AMIC technique were retrospectively analysed. Patients were assessed through the IKDC subjective knee evaluation questionnaire and the Lysholm scoring system. All patients underwent a complete imaging study including radiographs and magnetic resonance. The median defect size was found to be 4.3 (range 2.9–8) cm².

Results

At a median follow-up of 7 (±1.4) years, the mean IKDC score improved from 31.7 (±8.9) points preoperatively, to 80.6 (±5.3) at the latest follow-up (p < 0.05). The mean Lysholm score improved from 38.8 (±12.4) points preoperatively to 72.6 (±19.5) points at the last follow-up (p < 0.05). At the last follow-up, 76.2% of patients were satisfied or extremely satisfied with their outcomes, while 66.6% of patients showed good quality repair tissue on magnetic resonance imaging.

Conclusion

AMIC was found to be an effective method to treat full-thickness knee chondral defects larger than 2 cm², with significant clinical and functional improvement maintained over a 7-year follow-up.

Level of evidence

IV.

     

Combination of microfracture and periostal-flap for the treatment of focal full thickness articular cartilage lesions of the shoulder: a prospective study

Focal full-thickness articular cartilage lesions of the shoulder are less common than those of the lower extremity but are often symptomatic and may progress to degenerative osteoarthritis. This prospective study evaluated our clinical results for cartilage repair in five patients with chondral defects localized at the humeral head using a combination of microfracture and periostal flap, all by deltoidopectoral approach. Mean follow-up was 25.8 months (range 24-31) and consisted of a clinical examination, Constant score examination, radiography, and magnetic resonance imaging; three patients underwent a second-look arthroscopy an average of 8 months following cartilage repair. We found the Constant score significantly improved over the preoperative level, from 43.4% to 81.8%. Pain was reduced significantly to 18.6 points. Radiography and magnetic resonance imaging showed progression of the osteoarthritis in two patients. Second-look arthroscopy revealed a significantly reduced cartilage lesion. This is the first report of a combination of microfracture and a periostal flap for repair of focal full-thickness cartilage lesions at the shoulder. Short-term follow-up clinical results were satisfactory. It is essential to address the underlying pathology. Results must be reconfirmed in a long-term study.     

The treatment of chondral and osteochondral defects of the knee with autologous matrix-induced chondrogenesis (AMIC): method description and recent developments

Purpose  

Articular resurfacing by treatment of chondral defects may include chondral abrasion, autologous chondrocyte Implantation (ACI), matrix-induced chondrocyte transplantation (MACT) or osteochondral autologous transplantation (OATS). This technical note describes the method of autologous matrix-induced chondrogenesis (AMIC), a one-step procedure combining subchondral microfracture with the fixation of a collagen I/III membrane with fibrin glue or sutures.     

Articular cartilage lesions in 993 consecutive knee arthroscopies

BACKGROUND: Traumatic articular cartilage injuries heal poorly and may lead to development of osteoarthritis at a young age. This study estimates the number of patients who may benefit from one of the surgical methods of cartilage repair. METHODS: All patients undergoing knee arthroscopy during a 6-month period at three collaborating hospitals were consecutively evaluated according to the International Cartilage Repair Society (ICRS) knee form. The material consists of 993 consecutive knee arthroscopies in patients with median age of 35 years. RESULTS: Preoperative radiographs demonstrated degenerative changes in 13% of the knees. Articular cartilage pathology was found in 66% and a localized cartilage defect was found in 20% of the knees. A localized full-thickness cartilage lesion (ICRS grade 3 and 4) was observed in 11% of the knees. Of the localized full-thickness lesions, 55% (6% of all knees) had a size above 2 cm(2). CONCLUSION: Eleven percent of all knee arthroscopies show cartilage defects that may be suitable for cartilage repair procedures. However, the natural history of these lesions and the number of patients that will benefit from a cartilage repair procedure are so far unknown.     

Treatment of deep cartilage defects of the patella with periosteal transplantation

Twenty-six consecutive patients (19 men and 7 women) with a mean age of 31.5 years (range 19–52 years) who suffered from an isolated full-thickness cartilage defect of the patella (area ranged from 0.75 to 20.0 cm²) and disabling knee pain were treated with autologous periosteal transplantation (without any chondrocytes). The duration of symptoms was 59 months (range 11–144 months). During the first 5 postoperative days all patients were treated with continuous passive motion (CPM). This was followed by active motion, slowly progressive strength training, and slowly progressive weight-bearing. After a mean follow-up of 42 months (range 24–76 months), 17 patients (65%) were graded as excellent (were painfree), 8 patients (31%) as good (had pain with strenous knee-loading activities), and 1 patient as poor (had pain at rest). Twenty-two patients (85%) had returned to their previous occupation. Twelve patients (46%) had resumed sports or recreational activities at their former level. Repeated magnetic resonance imaging (MRI) investigations showed progressive, and finally complete, filling of the articular defects. Biopsies taken in five randomly selected cases showed hyaline-like cartilage. Patients with full-thickness cartilage defects of the patella and disabling knee pain can be treated with autologous periosteal transplantation (without any chondrocytes), followed by CPM, and slowly progressive strength training and weight-bearing. We believe this is a good method to accomplish regeneration of articular cartilage and satisfactory clinical results. Received: 25 March 1998 Accepted: 14 April 1998     

Autologous chondrocyte implantation in the knee using fibrin

Autologous chondrocyte implantation (ACI) is widely used to treat symptomatic articular cartilage injury of the knee. Fibrin ACI is a new tissue-engineering technique for the treatment of full-thickness articular cartilage defects, in which autologous chondrocytes are inserted into a three-dimensional scaffold provided by fibrin gel. The objective of this study is to document and compare mean changes in overall clinical scores at both baseline and follow-up. Fibrin ACI was used to treat deep cartilage defects of the femoral condyle in 30 patients. There were 24 men and 6 women with a median age of 35 years (range 15–55) and with a mean defect size of 5.8 cm² (range 2.3–12). Clinical and functional knee evaluations were performed using different scoring systems, MRI was performed 24 months postoperatively, and arthroscopy was performed 12 months postoperatively. All patients achieved clinical and functional status improvements following surgery (P < 0.01). The mean scores of the Henderson classification (MRI evaluation) significantly improved from 14.4 to 7 (P = 0.001), and no graft-associated complications were noted. Arthroscopic assessments performed 12 months postoperatively produced nearly normal (grade II) International Cartilage Repair Society scores in 8 of the 10 study patients. Fibrin ACI offers the advantages of technical simplicity, minimal invasiveness, a short surgery time, and easier access to difficult sites than classical ACI. Based on the findings of this clinical pilot study, we conclude that fibrin ACI offers a reliable means of treating articular cartilage defects of the knee.     

Arthroscopic repair of a chondrolabral lesion associated with anterior glenohumeral dislocation

Chondrolabral lesions are uncommon after anteroinferior glenohumeral dislocations. This report describes a new dual-lesion complex that involved an avulsion of the anteroinferior glenoid labrum and a flap tear of the adjacent articular cartilage [glenoid labral tear and articular cartilage flap (GLAF) lesion]. The chondral component involved a large undermined region of the anterior half of the lower glenoid articular cartilage, and the labral component involved an avulsion from the 2.30–6 o’clock position on the glenoid. The labral tear was reconstructed with 3 suture anchors to form a neo-labrum in an attempt to overlap and stabilize the periphery of the chondral flap. A meniscal repair device was used to place a mattress stitch in the cartilage periphery to further stabilize the flap. This technique resulted in a secure repair without any chondral damage, and this remained intact on an MRI performed at a 3-month follow-up. A final 12-month follow-up showed complete recovery, as assessed by the Oxford shoulder instability score and Rowe score, and by a return to the pre-injury sporting level.     

Biochemical and biomechanical properties of lesion and adjacent articular cartilage after chondral defect repair in an equine model

BACKGROUND: Chondral defects may lead to degradative changes in the surrounding cartilage, predisposing patients to developing osteoarthritis. PURPOSE: To quantify changes in the biomechanical and biochemical properties of the articular cartilage adjacent to chondral defects after experimental defect repair. STUDY DESIGN: Controlled laboratory study. METHODS: Specimens were harvested from tissue within (lesion), immediately adjacent to, and at a distance from (remote area) a full-thickness cartilage defect 8 months after cartilage repair with genetically modified chondrocytes expressing insulin-like growth factor-I or unmodified, control chondrocytes. Biomechanical properties, including instantaneous Young's and equilibrium aggregate moduli, were determined by confined compression testing. Biochemical properties, such as water and proteoglycan content, were also measured. RESULTS: The instantaneous Young's modulus, equilibrium modulus, and proteoglycan content increased, whereas water content decreased with increasing distance from the repaired lesion. The instantaneous Young's and equilibrium moduli of the adjacent articular cartilage were 80% and 50% that of remote area samples, respectively, whereas water content increased 0.9% and proteoglycan content was decreased by 35%. No significant changes in biomechanical and biochemical properties were found either in the lesion tissue or in adjacent cartilage with genetic modification of the chondrocytes. CONCLUSION: Articular cartilage adjacent to repaired chondral defects showed significant remodeling 8 months after chondral defect repair, regardless of whether genetically modified or unmodified cells were implanted. CLINICAL RELEVANCE: Changes in the biochemical and biomechanical properties of articular cartilage adjacent to repaired chondral defects may represent remodeling as part of an adaptive process or degeneration secondary to an altered distribution of joint forces. Quantification of these changes could provide important parameters for assessing progress after operative chondral defect repair.     

A comparative study of 3 different cartilage repair techniques

Purpose  

The value of cell-free techniques in the treatment of cartilage defects remains under debate. In this study, cartilage repair of full-thickness chondral defects in the knees of Goettinger minipigs was assessed by treatment with a cell-free collagen type-I gel or a collagen type-I gel seeded with autologous chondrocytes. As a control, abrasion arthroplasty was included.     

Osteochondral autologous transplantation versus microfracture for the treatment of articular cartilage defects in the knee joint in athletes

The purpose of this prospective randomized clinical study was to compare the outcomes of mosaic type autologous osteochondral transplantation (OAT) and microfracture (MF) procedures for the treatment of the articular cartilage defects of the knee joint in athletes. Between 1998 and 2002, a total of 57 athletes with a mean age of 24.3 years and with a symptomatic lesion of the articular cartilage in the knee were randomized to undergo either OAT or MF procedure. There were 28 athletes in OAT group and 29 in MF group. Patients were evaluated using a modified Hospital for Special Surgery (HSS) and International Cartilage Repair Society (ICRS) scores, MRI and clinical assessment after 6, 12, 24 and 36 months after the surgery. According to the modified HSS and ICRS scores, functional and objective assessment showed that 96% had excellent or good results after OAT compared with 52% after MF procedure (P<0.001). In 12, 24 and 36 months after the operations, the HSS and ICRS showed statistically significantly better results in the OAT group (P=0.03; P=0.006; P=0.006). Twenty-six (93%) athletes following OAT and fifteen (52%) athletes following MF returned to sports activities at the preinjury level at an average of 6.5 months (range, 4–8 months) after the operations. At an average of 37.1 months follow-up, our prospective, randomized, clinical study in athletes has shown significant superiority of the OAT over MF for the repair of articular cartilage defects in the knee.     

Treatment of tear of the anterior cruciate ligament combined with localised deep cartilage defects in the knee with ligament reconstruction and autologous periosteum transplantation

An acute tear of the anterior cruciate ligament (ACL) is frequently associated with injuries to the joint cartilage and subchondral bone. These injuries may progress to deep cartilage defects, causing disabling pain, and represent a therapeutic challenge in patients with the combination instability and pain. At our clinic we treat patients with the combined injury with simultaneous ACL reconstruction and autologous periosteum transplantation of the cartilage defect. This report describes the technique for periosteum transplantation of full-thickness cartilage defects in the medial femoral condyle. Our clinical report includes the first 7 patients (6 men and 1 woman, mean age 29.1 years at operation) who have been followed for 2 years or longer of 14 consecutive patients (12 men and 2 women). All patients had suffered a total tear of the ACL and a full-thickness defect of the cartilage at the medial femoral condyle. The cartilage defects had a mean area of 7.3 cm² (range 1.0–13.5 cm²). All patients had disabling instability and medial knee pain when walking. The anterior cruciate ligament was reconstructed with a bone-tendon-bone graft of the central third of the patellar ligament. After preparation of the cartilage lesion, the periosteum transplant was anchored to the underlying bone with suture anchors and fibrin glue. Postoperatively, these patients (n = 7) were initially treated with continuous passive motion, followed by active flexibility training and slowly progressing strength training and weight-bearing activities. At follow-up a mean of 31.3 months (range 24–38 months) later, 6 patients evidenced subjectively stable knees, no pain during rest or when walking, and had returned to not too heavy knee-loading work. One patient had a subjectively stable knee, but felt medial knee pain. Meticulous surgical technique and rigorous postoperative rehabilitation are probably of the greatest importance in this procedure. With the use of suture anchors and fibrin glue, the periosteum transplant can be well adapted to the condylar subchondral bone bed. Received: 14 April 1998 Accepted: 4 September 1998     

Prognostic value of chondral defects on the outcome after arthroscopic treatment of acetabular labral tears

Pathology of the acetabular labrum plays an increasing role in the treatment of hip pain. Hip arthroscopy has proven its clinical value as a useful procedure for successful treatment of labral tears. Until today, only a few studies have investigated the influence of articular cartilage defects on the clinical outcome of partial arthroscopic labrum resection in a larger patient population. We prospectively evaluated patients with an intraoperatively proven labral lesion/tear without any radiological and arthroscopical sign of a concomitant bony femoroacetabular impingement or hip dysplasia for a minimum postoperative follow-up of 2 years. Cartilage defects were classified according to Outerbridge and divided into two subgroups: Outerbridge ≤ 1 and Outerbridge ≥ 2, respectively. To evaluate combined results, various established scoring systems (visual analogue scale, modified Harris Hip Score, Larson Hip Score) were used. Out of 54 originally enrolled patients, 50 individuals (29 female, 21 male) with a median age of 33 years (range 15–49) were available for follow-up after a mean of 34 (range 24–48) months. At follow-up, the total study population experienced significant improvement in pain and in the combined evaluation scales (Larson Hip Score/MHHS). When patients were categorized into two subgroups, either with intraoperatively present or absent articular cartilage defects, our data indicated that subjects with no degenerative changes of the articular cartilage surface significantly improved in the applied clinically scoring systems. In contrast, in patients with an articular cartilage lesion during hip arthroscopy score values had a tendency to be unimproved or even deteriorated at follow-up. Regression analysis revealed a significant negative correlation between postoperative outcome and the grading of the coexistent articular cartilage defect. On the basis of our investigation, we conclude that partial arthroscopic resection of a torn labrum without attending bone deformity (dysplasia or femoroacetabular impingement) can reveal good and satisfied results. Depending on the extent of a coexisting articular cartilage defect subjective clinical results are compromised.     

Full-thickness cartilage lesion do not affect knee function in patients with ACL injury

There is debate in the literature regarding the impact of full-thickness cartilage lesion on knee function in patients with ACL injury. The hypothesis of the current study is that a full-thickness cartilage lesion at the time of ACL reconstruction does not influence knee function as measured by the Knee injury and Osteoarthritis Outcome Score (KOOS) in patients with ACL injury. Of the 4,849 primary ACL surgery cases in the Norwegian National Knee Ligament Registry as of 12 December 2007, 30 patients met the following inclusion criteria: a full-thickness cartilage lesion (International Cartilage Repair Society [ICRS] grades 3 and 4), age less than 40 years, no associated pathology or meniscus injury, and less than 1 year between knee injury and ACL reconstruction. Each of the 30 patients in this study group was matched with two control participants without cartilage lesions. Preoperatively, the patients completed the KOOS, and the surgeon recorded the location and size of the cartilage lesion and graded the cartilage injury according to ICRS standards. There were no significant differences between the case and control groups for any of the five subscales of the KOOS. A cartilage lesion was located in the medial compartment in 67% of the cases, in the lateral compartment in 20% of the cases, and in the patellofemoral joint in 13% of the cases. In conclusion, the combination of a full-thickness cartilage lesion and an ACL rupture did not result in inferior knee function at the time of the ACL reconstruction as measured by the KOOS.     

微骨折术治疗膝关节软骨损伤修复效果T2 star mapping评价研究

目的 本研究应用MRI对关节镜下微骨折法治疗膝关节软骨损伤修复效果进行大体组织形态学评估及定量分析.方法 本研究纳入14例有膝关节软骨损伤症状并接受关节镜下微骨折法治疗的病例进行回顾性病例分析.所有病例的关节软骨损伤均为ICRS分级Ⅲ或Ⅳ,术中测量病变面积为2～8cm^2.1年随访期内所有病例都接受常规MRI序列及T2 star mapping序列扫描（1.5T）.对损伤修复区域采用软骨组织修复磁共振观察评分系统（MOCART）进行评价.采用T2 star mapping序列扫描图像感兴趣区划分的方法对修复区域及自身正常软骨所测量的T2＊弛豫值进行分析比较.结果 1年随访期软骨修复区MOCART评分为59.50±23.90,相邻本体软骨组织评分为65.21±21.84,与软骨修复组间比较无显著差异.软骨修复区和邻近正常自体软骨组织T2＊弛豫时间分别为（31.14±9.26）ms和（32.93±11.69）ms,修复区软骨组织质地与正常软骨组织相近.结论 经关节镜下微骨折法修复膝关节软骨损伤后1年随访观察期内,MRI软骨扫描可见软骨损伤区填充良好.经T2＊测量值分析证实软骨修复组织可以达到与邻近正常透明软骨相近的组织结构.     

Ultrasound-Guided Radiofrequency Thermal Ablation of Uterine Fibroids: Medium-Term Follow-Up

Previous studies have shown that radiofrequency thermal ablation (RFA) of uterine fibroids through a percutaneous ultrasound (US)-guided procedure is an effective and safe minimally invasive treatment, with encouraging short-term results. The aim of this study was to assess the results in terms of volume reduction and clinical symptoms improvement in the midterm follow-up of fibroids with a diameter of up to 8 cm. Eleven premenopausal females affected by symptomatic fibroids underwent percutaneous US-guided RFA. Symptom severity and reduction in volume were evaluated at 1, 3, 6, 9, and 12 months. The mean symptom score (SSS) before the procedure was 50.30 (range 31.8–67.30), and the average quality of life (QOL) score value was 62 (range 37.20–86.00). The mean basal diameter was 5.5 cm (range 4.4–8) and the mean volume was 101.5 cm³ (range 44.58–278 cm³). The mean follow-up was 9 months (range 3–12 months). The mean SSS value at the end of the follow-up was 13.38 (range 0–67.1) and the QOL 90.4 (range 43.8–100). At follow-up the mean diameter was 3.0 cm (range 1.20–4.5 cm), and the mean volume was 18 cm³ (range 0.90–47.6 cm³). In 10 of 11 patients we obtained total or partial regression of symptoms. In one case the clinical manifestations persisted and it was thus considered unsuccessful. In conclusion, US-guided percutaneous RFA is a safe and effective treatment even for fibroids up to 8 cm.     

Superior results with continuous passive motion compared to active motion after periosteal transplantation A retrospective study of human patella cartilage defect treatment

Fifty-seven consecutive patients (33 men and 24 women), with a mean age of 32 years (range 16–53 years), who suffered from an isolated full-thickness cartilage defect of the patella and disabling knee pain of long duration, were treated by autologous periosteal transplantation to the cartilage defect. The first 38 consecutive patients (group A) were postoperatively treated with continuous passive motion (CPM), and the next 19 consecutive patients (group B) were treated with active motion for the first 5 days postoperatively. In both groups, the initial regimens were followed by active motion, slowly progressive strength training, and slowly progressive weight bearing. In group A, after a mean follow-up of 51 months (range 33–92 months), 29 patients (76%) were graded as excellent or good, 7 patients (19%) were graded as fair, and 2 patients (5%) were graded as poor. In group B, after a mean follow-up of 21 months (range 14–28 months), 10 patients (53%) were graded as excellent or good, 6 patients (32%) were graded as fair, and 3 patients (15%) were graded as poor. Altogether, nine of the fair or poor cases (50%) were diagnosed with chondromalacia of the patella. Our results, after performing autologous periosteal transplantation in patients with full-thickness cartilage defects of the patella and disabling knee pain, are good if CPM is used postoperatively. The clinical results using active motion postoperatively are not acceptable, especially not in patients with chondromalacia of the patella. Received: 24 November 1998 Accepted: 30 January 1999     

Synovial shelves of the knee: association with chondral lesions

The objectives of the present study were to evaluate whether synovial shelves of the knee are associated with increased incidence of chondral lesions and to determine which types of plica are associated with significant articular damage. Data were collected prospectively from 1,000 consecutive knee arthroscopies. Of these patients, 321 (32.1%) were found to have synovial shelves of the knee. Patients details (age, sex, duration of symptoms, injuries, and possible mechanism of injury), operative details (types and number of portals, equipment used), intra-articular findings (articular, meniscal and synovial lesions, and stability characteristics) and procedures performed were recorded on a special database. Synovial shelves of the knee were recorded using a modification of the Sakakibara classification. Articular lesions were noted on anatomic articular maps of the different functional zones using a functional zoning system that presaged the current ICRS system. An increased incidence of articular lesions was found in patients with synovial shelves, in comparison with patients without shelves (94.7 vs. 81% respectively; P < 0.001). Patients with larger and more fibrotic shelves were found to have increased incidence of cartilage lesions, in comparison with patients with type smaller and less fibrotic shelves (96.5 vs. 86.4%, respectively; P = 0.002), as well as cartilage lesions with bigger size (84 vs. 71.4%, respectively; P = 0.02). Patella (P < 0.001), and specific areas (P < 0.001) of the medial femoral condyle, were areas with increased incidence of cartilage lesions, in patients with synovial shelves. In conclusion, synovial shelves of the knee are associated with an increased incidence of cartilage lesions. Larger shelves, particularly with chronic inflammation are associated with more frequently occurring and larger articular lesions. Areas with increased incidence of chondral lesions, in patients with plicae, include particularly the lower patella and the non-weight-bearing medial femoral condyle.     

Microfracture treatment of single or multiple articular cartilage defects of the knee: a 5-year median follow-up of 110 patients

We compared the results of microfracture in single versus multiple symptomatic articular cartilage defects in the knee in 110 patients with a median age of 38 years (range 15–60). Cases of reoperation of the cartilage defect were classified as failures. Clinical outcome in non-failures was evaluated by the Lysholm score and grading of knee pain and function of the knee by the use of patient-administered visual analog scales (VAS; 0–100). Data were prospectively collected before the operation and at the 2- to 9-year follow-up. The single lesion or the largest of multiple lesions were located on the medial femoral condyle (n = 62), trochlea (n = 18), lateral tibia (n = 11), patella (n = 10) or lateral femoral condyle (n = 9). We treated one (n = 76), two (n = 27) or three (n = 7) lesions with a median total area of 4 cm² (range 1–15). A total of 24 failures (22%) were registered—18% in the single-defect subgroup and 29% in the multiple-defects subgroup. In the remaining group of patients (n = 86), the mean Lysholm score, mean pain-score (0 = no pain; 100 = worst possible pain) and mean function-score (0 = useless; 100 = full function) improved from 51, 52 and 41, respectively, to 71 (P < 0.001), 30 (P < 0.001) and 69 (P < 0.001) at the follow-up. The pain-score was significant lower (P = 0.042), and the function-score significantly higher (P = 0.001) in the group of patients with a single lesion compared to the group with 2 or 3 lesions. The Lysholm score did not differ significantly between the two subgroups (P = 0.06).