E3 ubiquitin ligase Casitas B lineage lymphoma-b and its potential therapeutic implications for immunotherapy

The distinction of self from non-self is crucial to prevent autoreactivity and ensure protection from infectious agents and tumors. Maintaining the balance between immunity and tolerance of immune cells is strongly controlled by several sophisticated regulatory mechanisms of the immune system. Among these, the E3 ligase ubiquitin Casitas B cell lymphoma-b (Cbl-b) is a newly identified component in the ubiquitin-dependent protein degradation system, which is thought to be an important negative regulator of immune cells. An update on the current knowledge and new concepts of the relevant immune homeostasis program co-ordinated by Cbl-b in different cell populations could pave the way for future immunomodulatory therapies of various diseases, such as autoimmune and allergic diseases, infections, cancers and other immunopathological conditions. In the present review, the latest findings are comprehensively summarized on the molecular structural basis of Cbl-b and the suppressive signaling mechanisms of Cbl-b in physiological and pathological immune responses, as well as its emerging potential therapeutic implications for immunotherapy in animal models and human diseases.

Radial head resection versus prosthetic arthroplasty in terrible triad injury: a retrospective comparative cohort study

Aims

The crucial role of the radial head in the stability of the elbow in terrible triad injury is acknowledged. This retrospective study aims to compare the results of resection of a severely comminuted radial head with or without prosthetic arthroplasty as part of the reconstruction for this injury.

Patients and Methods

The outcome of radial head resection was compared with prosthetic arthroplasty in 29 and 15 patients with terrible triad injuries, respectively. There were ten female patients (34.5%) in the resection group and six female patients (40%) in the prosthesis group. The mean age was 40.7 years (sd 13.6) in the resection group and 36 years (sd 9.4) in the prosthesis group. The mean follow-up of the patients was 24.4 months (sd 12) in the resection group and 45.8 months (sd 6.8) in the prosthesis group. Outcome measures included visual analogue scale (VAS) for pain, Mayo Elbow Performance Score (MEPS), Disabilities of Arm, Shoulder and Hand (DASH) Score, and range of movement. Postoperative radiological complications were also recorded.

Results

The mean ranges of extension, flexion, supination, and pronation were not significantly different between the two study groups (p = 0.75, p = 0.65, p = 0.82, and p = 0.68, respectively). The mean VAS score, DASH score, and MEPS of the two groups were also not statistically significantly different (p = 0.93, p = 0.19, and p = 0.32, respectively). At the final visit, the elbow was stable in all patients. No patient was found to have developed an Essex–Lopresti injury. Osteoarthritis grade I and II was observed in five and three patients of the resection group, respectively, and four and one patients of the arthroplasty group, respectively.

Conclusion

The outcome of patients undergoing treatment for terrible triad injuries is similar whether the patient’s radial head was excised or replaced. Cite this article: Bone Joint J 2018;100-B:1499–505.

Expansile aneurysmal bone cyst in the tubular bones of the hand treated with en bloc excision and autograft reconstruction: a report of 12 cases

Primary aneurysmal bone cysts (ABCs) in the small tubular bones of the hands are rare and optimal treatment is not yet established. Between August 1997 and June 2009, 12 patients with biopsy-proven expansile primary ABCs of the small tubular bones of the hand were treated with en bloc tumor excision and strut autograft reconstruction. The adjacent joint was preserved if feasible, otherwise it was fused. Patients were followed for at least 2 years (mean = 7 years). All grafts were incorporated except for partial resorption in one. There was only one tumor recurrence about 1 year after the operation. Other complications included premature physeal arrest in one case and limitation of adjacent joint motion in three. A relatively low rate of recurrence and other complications indicates that this technique would serve as a good strategy for patients with expansile ABCs in the hand in terms of safety, simplicity and reduced number of re-operations.

Congenital bilateral pseudarthrosis of the index metacarpal bones

Congenital pseudarthrosis is very rare in upper extremity, and has only previously been reported in the forearm. A case of bilateral congenital pseudarthrosis of the index metacarpal bones is described.

A variant of mirror hand. A case report

We describe a rare variant of mirror hand in a 20-year-old man who presented with multiple fingers. Radiographs revealed two ulnae (one vestigial) and a radius. There was duplication of the humeral head. The unique features of this case are the age of patient before the start of treatment and extension of the duplication proximal to the elbow.