Introduction and Aims: The aim of this study was to use biological, functional and radiographic evaluation to demonstrate that cultured autologous chondrocytes implanted using a type I/III collagen membrane leads to regeneration of hyaline-like articular cartilage in the knee.

Method: Approximately 70,000 knee arthroscopies are performed every year in Australia; 60% involve chondral surface defects. Three regenerative autologous cell therapy techniques have been used in Australia to treat full thickness chondral lesions:

periostial-covered autologous chondrocyte implantation (PACI);

The team at the University of Western Australia has concentrated on CACI and MACI techniques because of concerns over fibroblast formation and hypertrophy with PACI. Definitive evidence regarding the role of the membrane in enhancing chondrocyte-mediated cartilage regeneration is lacking.

Results: The series consists of a total of 71 patients who had failed previous surgical treatment prior to definitive collagen-covered ACI (32 implantations in 31 patients) or MACI (43 implantations in 40 patients). Biological, functional and radiographic evaluations were conducted pre-operatively, and post-operatively in order to determine the success of integration of implanted chondrocytes and categorise the level of restoration in knee joint function. Post-operative MRI scans at three months show oedematous tissue at the defect sites, contrasting with the fluid-filled defects seen pre-operatively. MRI scans at one, two and three years (collagen-covered) and one year (MACI) show normal cartilage signal. Apopototic test of chondrocytes before implantation showed that viability of chondrocytes was over 85% where apopototic rate of chondrocytes was less than 2%. Six-minute walk test and KOOS results indicate improved functional capacity following collagen covered and MACI.

Conclusion: Results from this clinical study indicate that the use of a type I/III collagen membrane in conjunction with ACI is a valid new approach for the treatment of chondral defects. Results from radiographic, functional and biological evaluations are encouraging. Ongoing follow-up will reveal the durability of reconstructions with CACI and MACI.

Introduction Displaced fractures of the midshaft clavicle often results in malunion with angulation and foreshortening. The purpose of this study is to determine the secondary effects of clavicular shortening on the sternoclavicular joint and scapulo-thoracic relationship, and to evaluate the symptomatic and biomechanical outcome in these patients.

Methods A series of 10 patients each with a malunited fractured clavicle defined by relative shortening of more than 15 mm were examined. A self-administered questionnaire for assessment of symptoms and function of the ipsilateral shoulder was completed for each patient. Computer tomography and three dimensional reconstructions of both shoulders were undertaken for static anatomical measurements. Biomechanical testing comparing both shoulders in each patient measured strength and velocity of movement. All subjects were symptomatic in the injured shoulder.

Results There were statistically significant differences between injured and uninjured shoulders for both mean shoulder scores and visual analog global assessments of shoulder function. Clavicular shortening produced statistically significant increased upward angulation of the clavicle at the sternoclavicular joint (p< 0.005), increased lateral displacement of the scapula on the posterior wall, and anterior scapular version (p< 0.05). Biomechanical differences were also recorded including a reduction in muscular strength for adduction, extension, and internal rotation of the humerus and also a reduced peak abduction velocity in the injured shoulder (p< 0.05).

Conclusions Changes in static sternoclavicular and scapulothoracic relationships occur following short malunion of the clavicle and are possible mechanisms limiting shoulder function after this injury. This study provides evidence that consideration should be given to prevention of clavicle malunion by open reduction and internal fixation, especially in the young and active age group.