This study reports the application of a novel method for quantitatively determining differences in the mechanical properties of healthy and torn rotator cuff tissues. In order to overcome problems of stress risers at the grip-tendon interface that can obscure mechanical measurements of small tendons, we conducted our investigation using dynamic shear analysis. Rotator cuff tendon specimens were obtained from 100 patients during shoulder surgery. They included 82 differently sized tears and 18 matched controls. We subjected biopsy samples of 3 mm in diameter to oscillatory deformation under compression using dynamic shear analysis. The storage modulus (G’) was calculated as an indicator of mechanical integrity. Normal tendons had a significantly higher storage modulus than torn tendons, indicating that torn tendons are mechanically weaker than normal tendons (p = 0.003). Normal tendons had a significantly higher mean shear modulus than tendons with massive tears (p <
0.01). Dynamic shear analysis allows the determination of shear mechanical properties of small tissue specimens obtained intra-operatively that could not be studied by conventional methods of tensile testing. These methods could be employed to investigate other musculoskeletal tissues. This pilot study provides some insight into mechanisms that might contribute to the failure of repair surgery, and with future application could help direct the most appropriate treatment for specific rotator cuff tears.
Most patients with a nightstick fracture of the
ulna are treated conservatively. Various techniques of immobilisation or
early mobilisation have been studied. We performed a systematic
review of all published randomised controlled trials and observational
studies that have assessed the outcome of these fractures following
above- or below-elbow immobilisation, bracing and early mobilisation.
We searched multiple electronic databases, related bibliographies and
other studies. We included 27 studies comprising 1629 fractures
in the final analysis. The data relating to the time to radiological
union and the rates of delayed union and nonunion could be pooled
and analysed statistically. We found that early mobilisation produced the shortest radiological
time to union (mean 8.0 weeks) and the lowest mean rate of nonunion
(0.6%). Fractures treated with above- or below-elbow immobilisation
and braces had longer mean radiological times to union (9.2 weeks,
9.2 weeks and 8.7 weeks, respectively) and higher mean rates of
nonunion (3.8%, 2.1% and 0.8%, respectively). There was no statistically
significant difference in the rate of non- or delayed union between
those treated by early mobilisation and the three forms of immobilisation
(p = 0.142 to p = 1.000, respectively). All the studies had significant
biases, but until a robust randomised controlled trial is undertaken
the best advice for the treatment of undisplaced or partially displaced
nightstick fractures appears to be early mobilisation, with a removable
forearm support for comfort as required. Cite this article:
Bone loss involving articular surface is a challenging
problem faced by the orthopaedic surgeon. In the hand and wrist,
there are articular defects that are amenable to autograft reconstruction
when primary fixation is not possible. In this article, the surgical
techniques and clinical outcomes of articular reconstructions in
the hand and wrist using non-vascularised osteochondral autografts
are reviewed.
We describe the use of a vascularised periosteal patch onlay graft based on the 1,2 intercompartmental supraretinacular artery in the management of 11 patients (ten men, one woman) with chronic nonunion involving the proximal third of the scaphoid. The mean age of the patients was 31 years (21 to 45) with the dominant hand affected in eight. Six of the patients were smokers and three had undergone previous surgery to the scaphoid. All of the proximal fragments were avascular. The presence of union was assessed using longitudinal axis CT. Only three patients progressed to union of the scaphoid and four required a salvage operation for a symptomatic nonunion. The remaining four patients with a persistent nonunion are asymptomatic with low pain scores, good grip strength and a functional range of wrist movement. Although this technique has potential technical advantages over vascularised pedicled bone grafting, the rate of union has been disappointing and we do not recommend it as a method of treatment.
This study examined the role of vitamin D as a factor accounting for fatty degeneration and muscle function in the rotator cuff. There were 366 patients with disorders of the shoulder. A total of 228 patients had a full-thickness tear (group 1) and 138 patients had no tear (group 2). All underwent magnetic resonance arthrography and an isokinetic muscle performance test. The serum concentrations of vitamin D (25(OH)D3) were measured. In general, a lower serum level of vitamin D was related to higher fatty degeneration in the muscles of the cuff. Spearman’s correlation coefficients were 0.173 (p = 0.001), −0.181 (p = 0.001), and −0.117 (p = 0.026) for supraspinatus, infraspinatus and subscapularis, respectively. In group 1, multivariate linear regression analysis revealed that the serum level of vitamin D was an independent variable for fatty degeneration of the supraspinatus and infraspinatus. The serum vitamin D level has a significant negative correlation with the fatty degeneration of the cuff muscle and a positive correlation with isokinetic muscle torque.