Introduction and Objectives: Cryopreservation as a meniscus conservation method affects cellularity to a lesser degree than simple freezing. Recent studies have shown that freezing alters meniscus ultrastructure. The effects of cryopreservatioin on the meniscus collagen net has not been so extensively studied. The aim of this study was to determine if cryopreservation alters meniscus ultrastructure and cellularity.

Materials and Methods: We obtained 10 external menisci for the purpose of studying their cellularity and collagen structure before and after cryoprservation at −180°C. We analyzed the architecture of the meniscus collagen using transmission electronic microscopy and assessed the degree to which this was altered according to a previously determined scale. We measured collagen fibers in transverse and longitudinal sections, and also calculated the percentage of cells that survived cryopreservation.

Results: Cryopreserved menisci averaged 4.8 points and the control menisci 4.1 (p< 0.17). In the cryopreserved menisci the collagen fibers in longitudinal section had a mean length of 12.61 nm and in the control menisci 13.38 nm (p=0.34), whereas in transverse sections the average was 15.48 nm and 16.7 nm respectively (p=0.41). The percentage of cells that survived cryopreservation went from 3.99 to 53.57%.

Discussion and Conclusions: Cryopreservation does not alter meniscus ultrastructure. Cell survival is highly variable. Results suggest that cryopreservation would be a more appropriate method than freezing at −80°C for the preservation of meniscal allografts.

Introduction: Prostheses radiolucent lines are currently used to evaluate the components fixation. The objective of this study is to determine concordance and reproducibility of humeral stem radiolucent lines evaluation.

Material and method: Five observers evaluated 64 x-ray belonging to 32 pairs (1 antero-posterior view and 1 outlet view) obtained from 16 shoulder prostheses. 16 x-ray pairs were obtained immediately after surgery and 16 one year after surgery. Evaluation in four degrees of radiolucent width for each of the 7 zones that the humeral component was divided for. Evaluation of the component-cement interface and the cement-bone interface. Each observer made two evaluations of the 64 x-ray separated in 6 weeks. Statistics : index kappa with quadratic weighting.

Results: Intra-observer results: mean kappa index for component-cement interface: 0,3274. mean kappa index for cement-bone interface: 0,5269. Inter-observer results: mean kappa index for component-cement interface: 0,1242. mean kappa index for cement-bone interface: 0,2478. Evaluation of 2 pairs of x-ray of the each prostheses taken in a period of 1 year: component-cement interface: mean of 91,67% of plausible results, cement-bone interface: mean of 80,2% of plausible Results:

Conclusions:

- low kappa index of reproducibility (0,3274–0,5269) of humeral component radiolucent lines evaluation for component-cement interface as well as for cement-bone interface.

INTRODUCTION: Shrinkage is one of the complications observed after allograft meniscal transplantation. Subtle immune rejection and alterations in meniscal permeability leading to nutritional deficit have been suggested as causes of shrinkage. The purpose of this study was to ascertain how freezing, one of the most common procedures used to preserve allografts, alters the collagen’s architecture.

METHODS: 26 fresh human external menisci were harvested in sterile conditions during TKR procedures. 13 of them were immediately frozen to −80° C while the rest were used as controls. All the menisci were cut, processed and preserved in a 2.0% glutaraldehyde and then analyzed with transmission electron microscopy. Four hundred collagen fibrils were recorded and measured in longitudinal and transversal sections in each meniscus. According to the collagen’s periodicity and degree of disruption, loss of banding, degree of collagen packing, fibril size variability and its intrafibrilar oedema, each meniscus was pointed from 0 to 7. Subsequently they were classified in grades ranging from a normal state (grade I; 0 to 2 points) to severe disarray (grade III; 5 to 7 points).

RESULTS: The fibril collagen diameters of those menisci that had been previously frozen showed an average size in the longitudinal section of 14.256 nm, whereas 17.279 nm were seen in the menisci used as controls (p=0.019). In the transverse section, the frozen menisci averaged 13.145 nm and 16.935 nm the controls (p=0.003).

Samples of the 13 previously frozen menisci were classified as grade III in 8 cases (61,54 %), and grade II in 5 cases (38.46 %). They averaged 4.846 points. The control groups were classified as grade I in 6 cases (46.154%) and grade II in 7 cases (53.85 %). The frozen menisci averaged 4.85 points whereas the control group did so 2.46 (p< 0.001)

CONCLUSIONS: The fibril diameters in frozen menisci showed a thinner diameter and had a higher degree of disarray. Therefore, the results suggest that the freezing process alters the menisci’s collagen net. This could partially explain the pathological changes found in shrunken menisci. This is the first work that quantified and qualified methodologically the collagen meniscal architecture and its potential changes.

Background: The Inferior Glenohumeral Ligament (IGHL) has a well known mechanical and propioceptive relevance in shoulder stability. The interrelation of the IGHL anatomical disposition and innervation has not actually been described. The studys purpose was to determine the IGHL innervation patterns and relate them to dislocation.

Material & methods: Forty-five embalmed and 16 fresh-frozen human cadaveric shoulders were studied. Massons Trichrome staining was used to detail the intra-ligamentous nerve fibre arrangements. Neural behaviour of the articular nerves was studied dynamically at the apprehension position and while anteroinferior dislocation of the shoulder joint was performed.

Results: The anatomy of the IGHL was clearly defined. However, in 7 out of 61 cases the anterior band was only a slight thickening of the ligament. It averaged 34 mm (range, 28 to 46 mm) in length. The posterior band was only seen in 40.98 % of the cases. The axillary nerve provided IGHL innervation in 95.08 % of the cases. We found two distinct innervation patterns originating in the axillary nerve. In Type 1 (29.5 % of the cases), one or two collaterals later diverged from the main trunk to enter the ligament. Type 2 (65.57%) showed innervation to the ligament provided by the posterior branch for three to four neural branches. In both cases, these branches enter the ligament near the glenoid rim and at 7 oclock position (right shoulder). The shortest distance to the glenohumeral capsule was noted at 5 oclock position. The radial nerve (Type 3 innervation pattern) provided IGHL innervation in 3.28 % (2 specimens). Microscopic analysis revealed wavy intraligamentous neural branches. The articular branches relaxed and separated from the capsule at external rotation and abduction and stayed intact after dislocation.

Conclusions: The current results showed the IGHL to have three different innervation patterns. The special neural anatomy of the IGHL suggested it was designed to avoiding denervation when dislocated. This might contribute to understand why the neural arch remains unaffected after most dislocations. To our knowledge this is the first work that clearly describes specimens in which the main innervation of the IGHL is provided by the radial nerve.

Knowledge of the neural anatomy of the shoulder will clearly help in avoiding its injury in surgical procedures.

Introduction and purpose: Different neurovascular structures may be damaged when making arthroscopic portals to the shoulder joint. The description of new portals poses new challenges. The goal of the present study is to provide an update on the anatomic vasculonervous responses of the current approaches to shoulder arthroscopy.

Materials and methods: 16 fresh cadavers were systematically dissected. The most usual arthroscopic portals were marked and, then, the dissection started on a plane-to-plane basis. Relationships were identified and distances were measured to the most important neurovascular elements with a standard caliber (accuracy: 0.5mm).

Results: The portals studied and the structures at risk were the following:

* Posterior portal: anterior branch of the axillary nerve and posterior circumflex artery 3.4 cm (range: 1.4 – 5); cutaneous branch of the axillary nerve 6.3 cm (range: 3.8 – 8.3), suprascapular nerve 2.8 cm (range: 2.1–3.3).

Conclusions: Although the crucial elements at risk when performing a shoulder arthroscopy are multiple, the axillary and suprascapular nerves were the most vulnerable structures to the different approaches. In spite of the presence of the “safe areas” described above, the neurovascular bundle was frequently affected by passage through the anteroinferior subaxillary portal. The results suggest that the use of this portal is not safe for routine arthroscopic practice.