Clavicular tunnel widening after acromioclavicular joint reconstruction: comparison between single and double clavicular tunnel techniques.

Acromioclavicular joint (ACJ) reconstruction using artificial ligaments is a common surgical treatment for Rockwood grade III or higher injuries. These techniques use bone tunnels in the clavicle and coracoid to insert the Tightrope implants. This multicenter retrospective study compares long term radiographic follow up of clavicular tunnel widening in two groups of patients with high-grade ACJ injury who underwent reconstruction using two different surgical techniques. The first group of 23 patients underwent an arthroscopic single clavicular tunnel ACJ reconstruction. The second group of 23 patiënts underwent an open double clavicular tunnel reconstruction. Inclusion criteria are Rockwood grade III or higher injury and minimum 18 months of follow-up. Exclusion criteria are distal clavicle fracture and additional stabilization techniques. Radiographic results were measured on anteroposterior shoulder radiographs taken at the first and last follow-up. Clavicular tunnel widening is the main outcome measurement. Secondary outcomes are heterotopic ligament calcifications, migration of buttons, tunnel fracture and loss of acromioclavicular reduction. The mean clavicular tunnel widening in the single clavicular tunnel technique is 1.91 mm. In the double clavicular tunnel technique, the widening of the medial tunnel is 2.52 mm and 3.59 mm in the lateral tunnel. The difference in widening between the single tunnel and the lateral tunnel is significant (p=0.003). A very clear observation on all follow-up X-rays was a reorientation of the clavicular tunnels towards the coracoid. The double clavicular tunnel technique has more tunnel widening in both tunnels compared to the single bundle technique.

The clinical importance of carpal instabilities following distal radial fractures.

A prospective study was undertaken to determine the clinical importance of the different carpal instabilities following dorsally displaced distal radial fractures (Colles' type). All patients were followed for 1 year and a Cooney score and X-ray evaluation were done. Nine different carpal instabilities were evaluated. Only dissociative DISI and ulnar translocation showed significant clinical differences at 1 year follow-up. It is therefore recommended that a dissociative DISI, usually caused by scapholunate dissociation, should be treated by percutaneous pinning at the time of the initial treatment.

Arthroscopy of the shoulder. Current concepts review.

Arthroscopy of the shoulder has become much more common in the past decade as surgeons have developed proficiency with the arthroscope in the knee and appropriate instrumentation has been developed. In recent years arthroscopic techniques adapted to the shoulder have continued to evolve from a diagnostic to a treatment-oriented modality. It is now recognized and accepted as both a diagnostic and therapeutic technique in orthopedic surgery. A thorough knowledge of the anatomy, disorders, arthroscopic variations and pathological findings is essential to successfully perform the procedure. This paper discusses the operating room set-up, the portal placement and the indications for arthroscopy of the shoulder.

Arthroscopic transglenoid suture of Bankart lesions.

Arthroscopic transglenoid suture of Bankart lesions was performed in 31 patients from 1988 to 1992. The diagnosis in all patients was recurrent traumatic anterior luxation, and a Bankart lesion was found in all cases. Mean time for clinical follow-up was 43 months (ranging from 25 to 76 months). A telephone review of all cases was obtained two years later. Five patients experienced postoperative wound problems posteriorly, where the sutures were tied over the fascia of the infraspinatus. One transient suprascapular nerve palsy was seen. There was a recurrence of complete dislocation in eight patients, while six patients had had repeated subluxations (total failure rate of 45.1%). Sixteen patients (51.6%) were assessed as having good to excellent results according to the Rowe scoring system. A slight loss of external rotation was found in six cases. Seventeen patients (54.8%) were able to return to their pre-injury level of athletic activity. Due to the high failure rate, we do not recommend arthroscopic transglenoid suture of Bankart lesions in patients with recurrent traumatic anterior dislocations.

In vitro generation of mature, naive antigen-specific CD8(+) T cells with a single T-cell receptor by agonist selection.

Peripheral blood T cells transduced with a tumor-specific T-cell receptor (TCR) face problems of auto-reactivity and lack of efficacy caused by cross-pairing of exogenous and endogenous TCR chains, as well as short term in vivo survival due to activation and growth factor-induced differentiation. We here studied an alternative strategy for the efficient generation of naive CD8(+) T cells with a single TCR. TCR-transduced human postnatal thymus-derived and adult mobilized blood-derived hematopoietic progenitor cells (HPCs) were differentiated to CD4(+)CD8(+) double-positive T cells using OP9-Delta-like 1 (OP9-DL1) cultures. Addition of the agonist peptide induced double positive cells to cross-present the peptide, leading, in the absence of co-stimulation, to cell cycle arrest and differentiation into mature CD8(+) T cells. Comprehensive phenotypic, molecular and functional analysis revealed the generation of naive and resting CD8(+) T cells through a process similar to thymic positive selection. These mature T cells show a near complete inhibition of endogenous TCRA and TCRB rearrangements and express high levels of the introduced multimer-reactive TCR. Upon activation, specific cytokine production and efficient killing of tumor cells were induced. Using this strategy, large numbers of high-avidity tumor-specific naive T cells can be generated from readily available HPCs without TCR chain cross-pairing.

A posteromedial working portal for arthroscopic subacromial decompression and acromioclavicular joint arthroplasty.

Arthroscopic subacromial decompression is traditionally performed through a posterolateral viewing portal and a lateral working portal. We describe the same procedure by using a posterolateral viewing portal and a posteromedial working portal. Because this portal is in the same sagittal plane as the ipsilateral acromioclavicular joint, it allows performing an arthroscopic excision arthroplasty of this joint.