Peter C. Kreuz

Clinical Efficacy of the Microfracture Technique for Articular Cartilage Repair in the Knee An Evidence-Based Systematic Analysis

Background Despite the popularity of microfracture as a first-line treatment for articular cartilage defects in the knee, systematic information on its clinical efficacy for articular cartilage repair and long-term improvement of knee function is not available. Hypothesis Systematic analysis of the existing clinical literature of microfracture in the knee can improve the understanding of the advantages and limitations of this cartilage repair technique and can help to optimize its indications and clinical outcomes. Study Design Systematic review. Methods A comprehensive literature search was performed using established search engines (MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials) to identify original human studies of articular cartilage repair with microfracture. Modified Coleman Methodology Scores were used to analyze the quality of the existing studies. Clinical efficacy of articular cartilage repair was evaluated by systematic analysis of short- and long-term functional outcome scores, macroscopic and microscopic repair cartilage quality, and findings of postoperative magnetic resonance imaging. Results Twenty-eight studies describing 3122 patients were included in the review. The average follow-up was 41 months, with only 5 studies reporting follow-up of 5 years or more. Six studies were randomized controlled trials and the mean Coleman Methodology Score was 58 (range, 22–97). Microfracture effectively improved knee function in all studies during the first 24 months after microfracture, but the reports on durability of the initial functional improvement were conflicting. Several factors were identified that affected clinical outcome. Defect fill on magnetic resonance imaging was highly variable and correlated with functional outcome. Macroscopic repair cartilage quality positively affected long-term failure rate, while the influence of histologic repair tissue quality remained inconclusive. Conclusion This systematic analysis shows that microfracture provides effective short-term functional improvement of knee function but insufficient data are available on its long-term results. Shortcomings of the technique include limited hyaline repair tissue, variable repair cartilage volume, and possible functional deterioration. The quality of the currently available data on micro-fracture is still limited by the variability of results and study designs. Further well-designed studies are needed to determine the long-term efficacy of microfracture and to define its specific clinical indications compared to other cartilage repair techniques.

Treatment of posttraumatic and focal osteoarthritic cartilage defects of the knee with autologous polymer-based three-dimensional chondrocyte grafts: 2-year clinical results

Autologous chondrocyte implantation (ACI) is an effective clinical procedure for the regeneration of articular cartilage defects. BioSeed®-C is a second-generation ACI tissue engineering cartilage graft that is based on autologous chondrocytes embedded in a three-dimensional bioresorbable two-component gel-polymer scaffold. In the present prospective study, we evaluated the short-term to mid-term efficacy of BioSeed-C for the arthrotomic and arthroscopic treatment of posttraumatic and degenerative cartilage defects in a group of patients suffering from chronic posttraumatic and/or degenerative cartilage lesions of the knee. Clinical outcome was assessed in 40 patients with a 2-year clinical follow-up before implantation and at 3, 6, 12, and 24 months after implantation by using the modified Cincinnati Knee Rating System, the Lysholm score, the Knee injury and Osteoarthritis Outcome Score, and the current health assessment form (SF-36) of the International Knee Documentation Committee, as well as histological analysis of second-look biopsies. Significant improvement (p < 0.05) in the evaluated scores was observed at 1 and/or 2 years after implantation of BioSeed-C, and histological staining of the biopsies showed good integration of the graft and formation of a cartilaginous repair tissue. The Knee injury and Osteoarthritis Outcome Score showed significant improvement in the subclasses pain, other symptoms, and knee-related quality of life 2 years after implantation of BioSeed-C in focal osteoarthritic defects. The results suggest that implanting BioSeed-C is an effective treatment option for the regeneration of posttraumatic and/or osteoarthritic defects of the knee.

Characteristic Complications After Autologous Chondrocyte Implantation for Cartilage Defects of the Knee Joint

Background Although autologous chondrocyte implantation (ACI) is a well-established therapy for the treatment of isolated cartilage defects of the knee joint, little is known about typical complications and their treatment after ACI. Hypothesis Unsatisfactory outcome after ACI is associated with technique-related typical complications. Study Design Case series; Level of evidence, 4. Methods A total of 309 consecutive patients with 349 ACI procedures of the knee joint were analyzed. Three different ACI techniques were used: periosteum-covered ACI in 52 cases (14.9%), Chondrogide (Geistlich Biomaterials, Wolhusen, Switzerland) membrane-covered ACI in 215 cases (61.6%), and a 3-dimensional matrix-associated ACI (BioSeed-C, Biotissue Technologies, Freiburg, Germany) in 82 cases (23.5%). In 52 patients, revision surgery was performed for persistent clinical problems. These patients were analyzed for defect size and location, technique of ACI, and intraoperative findings during revision surgery. The mean time of follow-up for patients after ACI was 4.5 years (standard deviation, ±1.5). Results Four typical major complications were identified: hypertrophy of the transplant, disturbed fusion of the regenerative cartilage and the healthy surrounding cartilage, insufficient regenerative cartilage, and delamination. These diagnoses covered a total of 88.5% of the patients who underwent revision surgery. The overall complication rate was highest in the group of patients treated with periosteum-covered ACI (P = .008). The incidence of symptomatic hypertrophy was 5.2% for all techniques and defect locations; the highest incidence was in patients treated with periosteum-covered ACI (15.4%) (P = .001). The incidence of disturbed fusion was highest in the Chondrogide-covered ACI (3.7%) and the matrix-associated ACI group (4.8%). Concerning the incidence of complications by defect location, there was a tendency for increased complications in patellar defects (P = .095). Within the patellar defects group, no correlation was found for the occurrence of delamination, insufficient regeneration, and disturbed fusion. As a statistical trend, an increased rate of hypertrophy was found for patellar defects (P = .091). Conclusion A major proportion of complications after ACI can be summarized by 4 major diagnoses (symptomatic hypertrophy, disturbed fusion, delamination, and graft failure). Among those, the overall complication rate and incidence of hypertrophy of the transplant were higher for periosteum-covered ACI. Furthermore, an increased rate of symptomatic hypertrophy was found for patellar defects. Therapeutic concepts need to be developed to treat these typical complications of ACI.

Mosaicplasty With Autogenous Talar Autograft for Osteochondral Lesions of the Talus After Failed Primary Arthroscopic Management A Prospective Study With a 4-Year Follow-up

Background There have been limited data in the literature reporting the results of osteochondral autografting for osteochondral lesions of the talus that have failed arthroscopic treatment. Hypothesis Osteochondral autografting can produce significant clinical improvement and a high rate of healing of osteochondral defects of the talus that have failed arthroscopic treatment. Study Design Cohort study; Level of evidence, 4. Methods Between 1998 and 2003, 35 patients (18 men, 17 women) with osteochondral talar lesions for which arthroscopic excision, curettage, and drilling had failed, underwent mosaicplasty with an osteochondral graft harvested from the ipsilateral talar articular facet. A malleolar osteotomy or a tibial wedge osteotomy was used for central or posterior lesions that could not otherwise be reached. The mean age of the patients was 30.9 years, and the mean follow-up was 48.9 months. Results The American Orthopaedic Foot and Ankle Society Ankle Hindfoot scale score in patients without osteotomy rose by 39 points (P =. 0001); with malleolar osteotomy, by 30.1 points (P =. 017); with tibial wedge osteotomy, by 34.9 points (P =. 0002); and with the posterolateral approach, by 32 points. The Wilcoxon test revealed a significant difference between patients without and with osteotomy (P =. 027) and between patients with malleolar and tibial wedge osteotomies (P =. 046). There were no patients with nonunion or malunion in the osteotomy groups. The score values corresponded with the subjective patient evaluation. The Spearman coefficient of correlation was. 89. Conclusion Osteochondral autografting with tibial wedge osteotomy is a good alternative to malleolar osteotomy in osteochondral talar lesions that have failed arthroscopic treatment and that cannot be reached in spite of a forced plantar flexion of the ankle. Patients with small osteochondral lesions accessible through an anterior approach without additional osteotomy have the best prognostic factors.

Two-Year Results of Open-Wedge High Tibial Osteotomy With Fixation by Medial Plate Fixator for Medial Compartment Arthritis With Varus Malalignment of the Knee

PURPOSE The purpose of our study was to evaluate the complications, technique-related risks, and the clinical course of patients treated with high tibial osteotomy (HTO) for medial arthritis of the knee with varus malalignment. METHODS Forty-three of 46 consecutive patients (follow-up, 93.5%) treated with HTO using the TomoFix implant (Synthes, Solothurn, Switzerland) were followed-up for 24 months. Radiographic and clinical data were collected preoperatively as well as 6, 12, and 24 months after surgery using standard instruments (Lysholm and subjective International Knee Documentation Committee score). RESULTS Excellent and good results were achieved in 67.5% of patients. Thirty-seven patients (86.0%) reported clinical improvement at 24 months compared to preoperative status. Evaluation of the clinical course following HTO revealed a significant increase in function after 12 (P < .01) and 24 (P < .01), but not at 6 months (P = .336) after surgery. A further increase was found between 12 and 24 months (P = .017); 67.5% of the study population returned to their predisease sports activity level at 24 months after surgery. Except for 1 case of intra-articular fracture, no severe intraoperative complications were found. One case of nonunion that demanded additional surgery was observed. CONCLUSIONS HTO with an open-wedge technique using the TomoFix implant seems to be a safe and efficient procedure. Our data show that postoperative recovery is long, with a majority of patients not reaching a functional end-point by 6 or 12 months. In many patients, further improvement was found after 12 months, which might be related to a removal of the implant. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Repair of Focal Cartilage Defects With Scaffold-Assisted Autologous Chondrocyte Grafts Clinical and Biomechanical Results 48 Months After Transplantation

Background Scaffold-assisted autologous chondrocyte implantation is a clinically effective procedure for cartilage repair, but biomechanical evaluations are still missing. Purpose This study was conducted to assess the clinical efficacy, including biomechanical analyses, of BioSeed-C treatment for traumatic and degenerative cartilage defects of the knee. Study Design Case series; Level of evidence, 4. Methods The authors evaluated the midterm clinical and biomechanical outcome of BioSeed-C, a cell-based fibrin-polymer graft for the treatment of cartilage defects. Clinical outcome at 4-year follow-up was assessed in 52 patients with full-thickness cartilage defects, International Cartilage Repair Society (ICRS) stage III and IV. Clinical scoring was performed preoperatively and 48 months after implantation using the Lysholm score, the International Knee Documentation Committee (IKDC) score, the ICRS score, the Knee injury and Osteoarthritis Outcome Score (KOOS), and the Noyes score. Cartilage regeneration was assessed by magnetic resonance imaging (MRI) using the Henderson-Kreuz score. Biomechanical evaluation was performed by isokinetic strength measurements, comparing healthy and operated knee of each patient. Results Clinical evaluation showed significant improvement in the Lysholm (from 51.8 preoperatively to 80.7 at 48 months postoperatively), IKDC (from 47.5 to 71.5), ICRS (from 3.8 to 2.0), KOOS (subcategory pain from 62 to 78, symptoms from 68 to 76, activities of daily living from 68 to 85, sports from 19 to 55, and quality of life from 30 to 55), and Noyes (from 31 to 59) scores (P ≤ .001) 48 months after implantation of BioSeed-C compared with the preoperative situation. The MRI evaluations showed moderate to complete defect filling in 43 of 44 treated patients. Two patients without improvement in the clinical and MRI scores received a total knee endoprosthesis after 4 years. Isokinetic evaluation showed significantly reduced maximum strength capacities for knee flexion and extension at the operated knee compared with the healthy knee (P < .05). Conclusion The clinical outcomes 4 years after graft implantation are good despite a persisting strength deficit. Implanting Bio-Seed-C is a promising treatment option for cartilage defects of the knee. More emphasis should be put on the rehabilitation of muscular strength.

Monteggia fractures in adults: LONG-TERM RESULTS AND PROGNOSTIC FACTORS

The objective of this retrospective study was to correlate the Bado and Jupiter classifications with long-term results after operative treatment of Monteggia fractures in adults and to determine prognostic factors for functional outcome. Of 63 adult patients who sustained a Monteggia fracture in a ten-year period, 47 were available for follow-up after a mean time of 8.4 years (5 to 14). According to the Broberg and Morrey elbow scale, 22 patients (47%) had excellent, 12 (26%) good, nine (19%) fair and four (8%) poor results at the last follow-up. A total of 12 patients (26%) needed a second operation within 12 months of the initial operation. The mean Broberg and Morrey score was 87.2 (45 to 100) and the mean DASH score was 17.4 (0 to 70). There was a significant correlation between the two scores (p = 0.01). The following factors were found to be correlated with a poor clinical outcome: Bado type II fracture, Jupiter type IIa fracture, fracture of the radial head, coronoid fracture, and complications requiring further surgery. Bado type II Monteggia fractures, and within this group, Jupiter type IIa fractures, are frequently associated with fractures of the radial head and the coronoid process, and should be considered as negative prognostic factors for functional long-term outcome. Patients with these types of fracture should be informed about the potential risk of functional deficits and the possible need for further surgery.

Pectoralis major tendon transfers above or underneath the conjoint tendon in subscapularis-deficient shoulders. An in vitro biomechanical analysis.

BACKGROUND Different operative techniques for transfer of the pectoralis major tendon have been proposed for the treatment of irreparable ruptures of the subscapularis tendon. The objective of this study was to compare the effects of two techniques of transferring the pectoralis major tendon (above or underneath the conjoint tendon) on glenohumeral kinematics during active abduction in a biomechanical model of a subscapularis-deficient shoulder. METHODS Six shoulder specimens were tested with a custom dynamic shoulder testing apparatus. After the kinematics of the intact shoulder were recorded, a complete tear of the subscapularis tendon was simulated surgically. A transfer of the clavicular portion of the pectoralis major muscle to the lesser tuberosity was then performed with the transferred tendon placed either above (tendon-transfer 1) or underneath (tendon-transfer 2) the conjoint tendon. For each condition, the maximum abduction angle as well as the external rotation angle and the superoinferior and anteroposterior humeral translations at the maximum abduction angle were recorded. RESULTS With the rotator cuff intact, the mean maximum glenohumeral abduction angle (and standard error of the mean) was 86.3 degrees +/- 2.1 degrees and the mean amount of external rotation at the maximum abduction angle was 5.5 degrees +/- 7.6 degrees . A complete tear of the subscapularis tendon decreased the mean maximum abduction angle to 40.8 degrees +/- 2.4 degrees (p < 0.001) and increased the mean external rotation to 91.8 degrees +/- 4.8 degrees (p < 0.001). The mean humeral translations in the anterior and superior directions (+3.4 +/- 0.5 and +6.3 +/- 0.3 mm, respectively) at the maximum abduction angle were also increased (p < 0.01 and p < 0.001) when compared with those in the intact shoulder. Significant differences were found in the mean maximum abduction angle as well as the mean external rotation angle and humeral translations (anterior and superior) at maximum abduction between the tendon-transfer-1 condition (63.2 degrees +/- 13.5 degrees , 82.4 degrees +/- 6.6 degrees , 4.0 +/- 1.8 mm, and 3.3 +/- 1.9 mm, respectively) and tendon-transfer-2 condition (89.5 degrees +/- 12.3 degrees , 45.7 degrees +/- 22.5 degrees , -0.6 +/- 2.0 mm, and 0.5 +/- 2.3 mm, respectively). The tendon-transfer-2 condition restored glenohumeral kinematics that were closer to those in the intact shoulder than were those resulting from the tendon-transfer-1 condition. CONCLUSIONS Transfer of the pectoralis major tendon in subscapularis-deficient shoulders partially restored the glenohumeral kinematics of the intact shoulder. One possible explanation for the superior effect of the tendon-transfer-2 condition is that, with a pectoralis major tendon transfer underneath the conjoint tendon, the line of action of the transferred tendon is closer to that of the subscapularis muscle.

Rehabilitation After Autologous Chondrocyte Implantation for Isolated Cartilage Defects of the Knee

Autologous chondrocyte implantation for treatment of isolated cartilage defects of the knee has become well established. Although various publications report technical modifications, clinical results, and cell-related issues, little is known about appropriate and optimal rehabilitation after autologous chondrocyte implantation. This article reviews the literature on rehabilitation after autologous chondrocyte implantation and presents a rehabilitation protocol that has been developed considering the best available evidence and has been successfully used for several years in a large number of patients who underwent autologous chondrocyte implantation for cartilage defects of the knee.

Mesenchymal Stem Cell-Based HLA-Independent Cell Therapy for Tissue Engineering of Bone and Cartilage

Mesenchymal stem cells (MSC) can be obtained from human bone marrow aspirates and, thanks to their differentiation potential and excellent in vitro culture properties, represent an attractive cell line for the regeneration of mesenchymal tissue. Both in vitro and in vivo, they can differentiate into cartilage, bone, tendons and fat cells, and-in contrast to embryonic stem cells-they are not under ethical scrutiny. Cultured on three-dimensional scaffolds according to the tissue engineering concept, they have already been successfully employed for reconstruction of mesenchymal tissues in numerous studies involving both small and large animal models. Recently, immunological properties of MSC have been investigated by several groups. On the basis of the available literature, MSC have to be referred to as immune privileged, and they seem to be available for HLA-independent cell transplantation. While clinical MSC transplantation has also been successfully performed in pilot studies in humans, numerous points still remain to be clarified, underscoring the need for further intensive research before large-scale clinical application can be contemplated. Only then can it be shown whether the associated high expectations are justified.