Abnormal bone geometry at the metacarpal bone shaft of rheumatoid arthritis patients with maintained muscle-bone relationship

OBJECTIVES:: Metacarpal juxta-articular bone is altered in Rheumatoid Arthritis (RA). However, a detailed analysis of disease related geometrical adaptations of the metacarpal shaft is missing. The aim of the present study was to assess the role of RA disease, forearm muscle cross-sectional area (CSA), age and sex on bone geometry at the metacarpal shaft. METHODS:: In 64 RA patients and 128 control subjects geometric properties of the third metacarpal bone mid-shaft and forearm muscle CSA were measured by peripheral quantitative computed tomography (pQCT). Linear models were performed for cortical CSA, total bone CSA, polar stress-strain Index (polar SSI, a surrogate for bone's resistance to bending and torsion), cortical thickness and Metacarpal Index (MI=cortical CSA/total CSA) with explanatory variables muscle CSA, age, RA status and sex. RESULTS:: Forearm muscle CSA was associated with cortical and total metacarpal CSA, and polar SSI. RA group status was associated with all bone parameters except cortical CSA. There was a significant interaction between RA status and age, indicating that the RA group had a greater age-related decrease in cortical CSA, cortical thickness and MI. CONCLUSIONS:: Bone geometry of the metacarpal shaft is altered in RA patients compared to healthy controls. While bone mass of the metacarpal shaft is adapted to forearm muscle mass, cortical thickness and MI are reduced but outer bone shaft circumference and polar SSI increased in RA patients. These adaptations correspond to an enhanced aging pattern in RA patients.

Comminuted fractures of the radial head and neck: is fixation to the shaft necessary?

Mason type III fractures of the radial head are treated by open reduction and internal fixation, resection or prosthetic joint replacement. When internal fixation is performed, fixation of the radial head to the shaft is difficult and implant-related complications are common. Furthermore, problems of devascularisation of the radial head can result from fixation of the plate to the radial neck. In a small retrospective study, the treatment of Mason type III fractures with fixation of the radial neck in 13 cases (group 2) was compared with 12 cases where no fixation was performed (group 1). The mean clinical and radiological follow-up was four years (1 to 9). The Broberg-Morrey index showed excellent results in both groups. Degenerative radiological changes were seen more frequently in group 2, and removal of the implant was necessary in seven of 13 cases. Post-operative evaluation of these two different techniques revealed similar ranges of movement and functional scores. We propose that anatomical reconstruction of the radial head without metalwork fixation to the neck is preferable, and the outcome is the same as that achieved with the conventional technique. In addition degenerative changes of the elbow joint may develop less frequently, and implant removal is not necessary.

[The AO/ASIF Flexnail : A flexible intramedullary nail for the treatment of humeral shaft fractures]

BACKGROUND: The use of conventional implants for intramedullary nailing of humeral shaft fractures is associated with specific difficulties. During antegrade implantation structures of the rotator cuff can be affected leading to a reduced functional result of the shoulder. If the nail is implanted in a retrograde manner problems arise due to a relatively large hole close to or within the olecranon fossa, which is necessary for insertion of the nail. Supracondylar fractures as well as persistent elbow pain and loss of function are reported in the literature. To overcome these disadvantages a flexible nail has been developed that can be stiffened and locked after implantation. METHOD: Between October 2000 and February 2002, 34 patients were treated with the flexible nail at our institution; 29 were available for follow-up. Fracture healing was documented on radiographs and clinical outcome was evaluated with use of the Constant as well as the Kwasny score. RESULTS: Median duration until fracture consolidation was 10 weeks. In two patients fracture union was not achieved within the follow-up period. The median outcome measured with the Constant score was 93 points and 2.5 with the Kwasny score. Both values correspond to a very good functional outcome. CONCLUSION: We conclude that the flexible humeral nail is an excellent treatment option for humeral shaft fractures. Damage to the rotator cuff and the distal humerus can be avoided due to its unique flexible construction, improving the functional outcome of intramedullary nailing for the treatment of humeral shaft fractures.

The "flap-shaft" prosthesis for insensate feet with Chopart or Lisfranc amputations

BACKGROUND: The inevitable detachment of tendons and the loss of the forefoot in Chopart and Lisfranc amputations result in equinus and varus of the residual foot. In an insensate foot these deformities can lead to keratotic lesions and ulcerations. The currently available prostheses cannot safely counteract the deforming forces and the resulting complications. METHODS: A new below-knee prosthesis was developed, combining a soft socket with a rigid shaft. The mold is taken with the foot in the corrected position. After manufacturing the shaft, the lateral third of the circumference of the shaft is cut away and reattached distally with a hinge, creating a lateral flap. By closing this flap the hindfoot is gently levered from the varus position into valgus. Ten patients (seven amputations at the Chopart-level, three amputations at the Lisfranc-level) with insensate feet were fitted with this prosthesis at an average of 3 (range 1.5 to 9) months after amputation. The handling, comfort, time of daily use, mobility, correction of malposition and complications were recorded to the latest followup (average 31 months, range 24 to 37 months after amputation). RESULTS: Eight patients evaluated the handling as easy, two as difficult. No patient felt discomfort in the prosthesis. The average time of daily use was 12 hours, and all patients were able to walk. All varus deformities were corrected in the prosthesis. Sagittal alignment was kept neutral. Complications were two minor skin lesions and one small ulcer, all of which responded to conservative treatment, and one ulcer healed after debridement and lengthening of the Achilles tendon. CONCLUSIONS: The "flap-shaft" prosthesis is a valuable option for primary or secondary prosthetic fitting of Chopart-level and Lisfranc-level amputees with insensate feet and flexible equinus and varus deformity at risk for recurrent ulceration. It provided safe and sufficient correction of malpositions and enabled the patients to walk as much as their general condition permitted.

Early versus delayed application of Thomas splints in patients with isolated femur shaft fractures: The benefits quantified

AIMS To investigate and quantify the clinical benefits of early versus delayed application of Thomas splints in patients with isolated femur shaft fractures. MATERIALS AND METHODS Level IV retrospective clinical and radiological analysis of patients presenting from January to December 2012 at a Level 1 Trauma Unit. All skeletally mature patients with isolated femur shaft fractures independently of their mechanism of injury were included. Exclusion criteria were: ipsilateral fracture of the lower limb, neck and supracondylar femur fractures, periprosthetic and incomplete fractures. Their clinical records were analysed for blood transfusion requirements, pulmonary complications, surgery time, duration of hospital stay and analgesic requirements. RESULTS A total of 106 patients met our inclusion criteria. There were 74 males and 32 females. Fifty seven (54%) patients were in the 'early splinted' group and 49 patients (46%) were in the 'delayed splinted' group (P>0.05). The need for blood transfusion was significantly reduced in the 'early splinted' group (P=0.04). There was a significantly higher rate of pulmonary complications in the 'delayed splinted' group (P=0.008). All other parameters were similar between the two groups. CONCLUSION The early application of Thomas splints for isolated femur fractures in non-polytraumatised patients has a clinically and statistically significant benefit of reducing the need for blood transfusions and the incidence of pulmonary complications.

Reduced trabecular bone mineral density and cortical thickness accompanied by increased outer bone circumference in metacarpal bone of rheumatoid arthritis patients: a cross-sectional study

Introduction The objective of this study was to assess three-dimensional bone geometry and density at the epiphysis and shaft of the third meta-carpal bone of rheumatoid arthritis (RA) patients in comparison to healthy controls with the novel method of peripheral quantitative computed tomography (pQCT). Methods PQCT scans were performed in 50 female RA patients and 100 healthy female controls at the distal epiphyses and shafts of the third metacarpal bone, the radius and the tibia. Reproducibility was determined by coefficient of varia-tion. Bone densitometric and geometric parameters were compared between the two groups and correlated to disease characteristics. Results Reproducibility of different pQCT parameters was between 0.7% and 2.5%. RA patients had 12% to 19% lower trabecular bone mineral density (BMD) (P ≤ 0.001) at the distal epiphyses of radius, tibia and metacarpal bone. At the shafts of these bones RA patients had 7% to 16% thinner cortices (P ≤ 0.03). Total cross-sectional area (CSA) at the metacarpal bone shaft of pa-tients was larger (between 5% and 7%, P < 0.02), and relative cortical area was reduced by 13%. Erosiveness by Ratingen score correlated negatively with tra-becular and total BMD at the epiphyses and shaft cortical thickness of all measured bones (P < 0.04). Conclusions Reduced trabecular BMD and thinner cortices at peripheral bones, and a greater bone shaft diameter at the metacarpal bone suggest RA spe-cific bone alterations. The proposed pQCT protocol is reliable and allows measuring juxta-articular trabecular BMD and shaft geometry at the metacarpal bone.