There have been conflicting reports on the effects of gamma irradiation on the material properties of cortical allograft bone. To investigate changes which result from the method of preparation, test samples must be produced with similar mechanical properties to minimise variations other than those resulting from treatment.

We describe a new method for the comparative measurement of bone strength using standard bone samples. We used 233 samples from six cadavers to study the effects of irradiation at a standard dose (28 kGy) alone and combined with deep freezing. We also investigated the effects of varying the dose from 6.8 to 60 kGy (n = 132).

None of the treatments had any effect on the elastic behaviour of the samples, but there was a reduction in strength to 64% of control values (p < 0.01) after irradiation with 28 kGy. There was also a dose-dependent reduction in strength and in the ability of the samples to absorb work before failure

We suggest that irradiation may cause an alteration in the bone matrix of allograft bone, but provided it is used in situations in which loading is within its elastic region, then failure should not occur.

Summary Statement. Bio-impedance analysis (BIA) provides a convenient method for the estimation of whole body and segmental measurement of skeletal muscle mass (SMM). BIA-measured SMM parameters may be effectively used for the normalisation of muscle strength and removing body-size dependence. Introduction. Despite an increasing interest in using bio-impedance analysis (BIA) for the estimation of segmental skeletal muscle mass (SMM); existing data is sparse. On the other hand, there is a need for better understanding of the influence of SMM on gender-related differences in muscle strength. Using BIA technique, this study aimed to measure the SMM, determine its correlation with muscle strength, and examine its relation with gender-related differences in muscle strength. Patients and Methods. Segmental and whole body SMM (3-segment electrode configuration) and maximum voluntary contraction in five distinct shoulder planes (forward flexion, abduction in scapular plane, abduction in coronal plane, and internal- and external rotation) were measured in 45 healthy participants (22 males, 23 females) with a mean age of 30.3 years. Independent t-tests and Pearson Correlation test were applied for comparative and correlational analysis, respectively. Results. All muscle-related parameters including muscle volume, SMM, and SMM index were significantly different between men and women. There was a significant gender-related difference in the absolute shoulder strength but not after normalisation to SMM. A strong correlation was found between strength and SMM and in-between strength measurements. Conclusion. BIA provided a convenient method for SMM estimation. SMM parameters may be effectively used for strength normalisation allowing comparisons of individuals with differing body masses. Strong correlations between SMM and muscle strength supported the use of BIA in assessing muscle size-strength relations and its applicability in muscle function assessments

Summary. Arthroscopic decompression of the lunate decreases clinical symptoms and slows progression of Kienböck's Disease. Introduction. The purpose of this study was to investigate the outcomes of patients suffering from avascular necrosis of the lunate, or Kienböck's Disease, who received arthroscopic decompression to treat the ischemic lunate. Previous studies have demonstrated an elevated intraosseus pressure in the ischemic lunate, and it has been hypothesised that ischemia in the lunate is secondary to this elevated pressure and subsequent venous congestion, as opposed to diminished arterial supply. Based on this work we have used decompression of the lunate to prevent progression of the disease. Patients and Methods. 21 patients, (22 wrists), reported to a single surgeon with a chief complaint of unremitting wrist pain and the subsequent diagnosis was Kienböck's disease, stages I, II, IIIA or IIIB. Range of motion measurement and grip strength, as well as self-reported outcome measures such as Disabilities of the Arm, Shoulder and Hand (DASH) and Modified Mayo, were obtained preoperatively and post operatively at 2, 7 and 12 months. The patients were treated operatively with arthroscopic decompression of the lunate. The lunate was approached dorsally at the interosseous lunotriquetral and the scapholunate ligament areas with an arthroscopic shaver until brisk bleeding was achieved upon deflating the tourniquet. In some cases, the core of the lunate had to be penetrated with a 45 k-wire until bleeding was obtained. Of the 22 wrists treated arthroscopically with lunate decompression, 18 had both pre-surgical and post-surgical follow-up evaluations. Results. The patients who underwent lunate arthroscopic decompression surgery demonstrated a statistically significant improvement in DASH score at 7 and 12 months postoperatively (p<0.05). The preoperative DASH score average for this cohort was 51, while post-operative DASH scores averaged 23 and 17 at 7 and 12 months, respectively. The patients also demonstrated some overall improvement in pain, functionality, range of motion, and grip strength as demonstrated by the Modified Mayo wrist score. Notably, the patients demonstrated statistically significant improvement in grip strength post-operatively at 7-months (p<0.05) and 12-months (p<0.01). In addition, there was noted to be improvement in supination and ulnar deviation measurements post-operatively at 7 months and 12 months, respectively. Conclusion. This study demonstrates the clinical outcome of arthroscopic decompression of the lunate in patients suffering from Kienböck's Disease using the patient's subjective evaluations as well as range of motion and grip strength measurements. Arthroscopic decompression of the lunate decreases clinical symptoms and slows progression of Kienböck's Disease using a less invasive surgical intervention

Objectives

The aim of this study was to systematically review the literature on measurement of muscle strength in patients with femoroacetabular impingement (FAI) and other pathologies and to suggest guidelines to standardise protocols for future research in the field.

The ability to predict load-bearing capacity during the consolidation phase in distraction osteogenesis by non-invasive means would represent a significant advance in the management of patients undergoing such treatment. Measurements of stiffness have been suggested as a promising tool for this purpose. Although the multidimensional characteristics of bone loading in compression, bending and torsion are apparent, most previous experiments have analysed only the relationship between maximum load-bearing capacity and a single type of stiffness. We have studied how compressive, bending and torsional stiffness are related to the torsional load-bearing capacity of healing callus using a common set of samples of bone regenerate from 26 sheep treated by tibial distraction osteogenesis.

Our findings showed that measurements of torsional, bending and compressive stiffness were all suitable as predictors of the load-bearing capacity of healing callus. Measurements of torsional stiffness performed slightly better than those of compressive and bending stiffness.