Innovations in oscillating bone saw blades

The purpose of this study was to identify some of the determinants of saw-blade design that influence bone-cutting performance. Using a reproducible experimental model, saw-blade performance was judged by measuring the blade temperature and the rate of bone removal. The results of this study demonstrated that the rake angle and blade swing radius had significant influence on saw-blade performance.     

Durability of oscillating bone saw blades

The purpose of this study was to measure the durability of disposable saw blades using a standard bone-cutting experimental model that can be replicated in any laboratory. Using a constant cutting force, the bone-cutting efficiency was determined by recording the maximum cutting temperature and the rate of material removal. In this experimental study, porcine femurs as well as a synthetic bone substitute were used as the test samples for measuring cutting efficiency. Repeated cutting of these test materials did not significantly alter the performance of the disposable bone-cutting blades.     

A technique for quantifying the performance of oscillating bone saw blades

A new model has been developed to evaluate the performance of oscillating surgical saw blades used in medical-implant procedures. A test apparatus was constructed to maintain a constant cutting force between a blade driven by a pneumatic powered oscillating saw and the bone. Evaluations of saw-blade performance were determined using the following outcome measures: cutting time, volume of bone removal, and peak cutting temperature. Two popular, commercially available blades similar in size and tooth geometry were evaluated. This model identified differences in the performance of these two types of oscillating saw blades.     

Healing of osteotomy sites applying either piezosurgery or two conventional saw blades: a pilot study in rabbits

Purpose

The purpose of this study was to compare bone healing of experimental osteotomies applying either piezosurgery or two different oscillating saw blades in a rabbit model.

Methods

The 16 rabbits were randomly assigned into four groups to comply with observation periods of one, two, three and five weeks. In all animals, four osteotomy lines were performed on the left and right nasal bone using a conventional saw blade, a novel saw blade and piezosurgery.

Results

All three osteotomy techniques revealed an advanced gap healing starting after one week. The most pronounced new bone formation took place between two and three weeks, whereby piezoelectric surgery revealed a tendency to faster bone formation and remodelling. Yet, there were no significant differences between the three modalities.

Conclusions

The use of a novel as well as the piezoelectric bone-cutting instrument revealed advanced bone healing with a favourable surgical performance compared to a traditional saw.     

A comparative study of bone shortening and bone loss with use of saw blades versus burr in hallux valgus surgery

BackgroundThe aim of this study was to assess bone loss and thickness of the cut with the use of a burr in percutaneous hallux valgus surgery.MethodsTwelve blocks of saw bone were used. Cuts of same depth were made in each block with two different saw blades and a burr. Each block was assessed for bone loss and thickness of the cut.ResultsThere was statistically significant (p < 0.05) increased bone loss and thickness of the cuts with the use of a burr as compared to use of two different saw blades. The use of a burr resulted in threefold increased loss of bone material and fourfold increase in the thickness of the cut as compare to use of two different saw blades.ConclusionThe metatarsal shortening is a risk factor in percutaneous hallux valgus surgery with the use of a burr.     

Regenerative medicine in orthopaedic surgery.

Regenerative medicine holds great promise for orthopaedic surgery. As surgeons continue to face challenges regarding the healing of diseased or injured musculoskeletal tissues, regenerative medicine aims to develop novel therapies that will replace, repair, or promote tissue regeneration. This review article will provide an overview of the different research areas involved in regenerative medicine, such as stem cells, bioinductive factors, and scaffolds. The potential use of stem cells for orthopaedic tissue engineering will be addressed by presenting the current progress with skeletal muscle-derived stem cells. As well, the development of a revascularized massive allograft will be described and will serve as a prototypic model of orthopaedic tissue engineering. Lastly, we will describe current approaches used to design cell instructive materials and how they can be used to promote and regulate the formation of bony tissue.     

The influence of an orthopaedic walker boot on forefoot force

BackgroundIn the treatment of an Achilles tendon rupture the patients are commonly equipped with an orthopaedic walker boot with wedges. To what extent this influences the tensile force placed on the Achilles tendon is unclear.PurposeTo assess the forefoot force and describe changes in muscle activity of the medial gastrocnemius, soleus and tibialis anterior when using one or three wedges during ambulation in a weightbearing orthopaedic walker boot.MethodsThe force on the forefoot was measured with a force sensor insole and muscle activity of the medial gastrocnemius, soleus and tibialis anterior were measured using surface electromyography in 10 healthy participants. Three different types of ambulation were performed (walking without crutches (unass.), walking with crutches (+crutch) and walking with crutches and verbal instructions to place body weight on heel (heel + crutch) with one and three heel wedges respectively.FindingsThe total peak force displayed an interaction where forefoot force decreased when wearing three wedges only for the +crutch ambulation type (80 N, p = 0.001) although there was a trend to decrease with three wedges also for the heel + crutch ambulation type (48 N, p = 0.05). The relative peak force on the forefoot showed a main effect with a significant decrease when using three wedges compared to one wedge across all three ambulation types (19.1%, p = 0.009).InterpretationThe force on the forefoot and hereby the Achilles tendon significantly decreased when using three wedges compared to one wedge. These findings have important implications for the rehabilitation post Achilles tendon rupture.     

PCA in paediatric orthopaedic patients: influence of a NSAID on morphine requirement

Ninety-seven consecutive children (5-16 years of age), who underwent a major orthopaedic operation received patient controlled analgesia (PCA) as their main therapy for postoperative pain. A Pharmacia Deltec^TM pump was used with a bolus dose of 25 μg·kg^?1 of morphine, a lock-out period of 8 min, and a maximally delivered dose of 0.1 mg·kg^?1 in an hour. Two-thirds of the patients were allocated to receive a concomitant non-steroidal anti-inflammatory drug (NSAID), either ibuprofen 40 mg·kg^?1 or diclofenac 2 mg·kg^?1 daily. Individual morphine requirement varied greatly (range 0.1-1.6 mg·kg^?1 in a day) and could not be predicted preoperatively. It was 29% less in patients receiving a NSAID (0.53 ± 0.35 (SD) vs 0.75 ± 0.28 mg·kg^?1 during the first postoperative day, P= 0.002). Patient's age did not influence morphine requirement, but patients with nausea took 23% less morphine than other patients (P= 0.023). Postoperative nausea was more frequent in patients having a NSAID (52 vs 31%, P= 0.027). The principle of PCA made it possible to cover even a wide individual range of postoperative opioid requirement with great patient satisfaction.     

Percutaneous osteotomies. Osteotome and Gigli saw techniques

Traditional methods of performing tibial and femoral corticotomies is discussed and then the modification using a percutaneous Gigli saw is explained. Advantages of the procedure are detailed, and numerous illustrations aid the reader.     

Guidelines in orthopaedic surgery. A first step

Guidelines are systematically developed statements of the actual knowledge in order to assist doctors and patients by the decision of appropriate health care. Since 1998 the DGOT has published 22 well structured guidelines, 20 guidelines are under construction. The AWMF as the coordinator of guideline constructing of all scientific medical societies has published 629 guidelines since 1995. The publication of guidelines of the DGOT and the BVO is the first step for dissemination, next steps should be implementation und evaluation. Then it will be evident whether change in medical practice will occur.     

Lyme arthritis in children. An orthopaedic perspective

The cases of forty-three children with clinical and serological evidence of Lyme arthritis that was diagnosed between August 1983 and July 1985 were evaluated. The mean length of follow-up was twenty months, with a range of five to thirty months. All of the children lived in or had visited an area where the disease was known to be endemic. Arthritis was the presenting feature in more than half of the children, and half of the children had initially consulted an orthopaedic surgeon, none of whom made the correct diagnosis. Only twenty patients had a history of erythema chronicum migrans, the characteristic rash that precedes the arthritis, and for only nineteen children was there any recollection of having been bitten by a tick. Three patients had Bell palsy and one had a popliteal cyst in conjunction with the arthritis. All of the patients had oligoarticular involvement. The knee was involved in all but two patients. Recurrent attacks of synovitis were common. Effusion was the only radiographic abnormality that was observed, and it was found in thirty-two patients. The sedimentation rate was elevated in thirty of thirty-six patients. Immunofluorescent serology for Lyme disease, which is sensitive and specific, was uniformly positive. Of thirty-three patients who were treated with oral administration of penicillin or tetracycline alone, thirty-one responded, while two patients who had recurrent attacks of the disease responded to parenteral administration of antibiotics. The remaining ten patients responded to combinations of orally and parenterally administered antibiotics. Longer follow-up is needed to further document the apparently low rate of relapse after antibiotic therapy in this young population.