Greater inadvertent muscle damage in direct anterior approach when compared with the direct superior approach for total hip arthroplasty.

AIMS: We wished to quantify the extent of soft-tissue damage sustained during minimally invasive total hip arthroplasty through the direct anterior (DA) and direct superior (DS) approaches. MATERIALS AND METHODS: In eight cadavers, the DA approach was performed on one side, and the DS approach on the other, a single brand of uncemented hip prosthesis was implanted by two surgeons, considered expert in their surgical approaches. Subsequent reflection of the gluteus maximus allowed the extent of muscle and tendon damage to be measured and the percentage damage to each anatomical structure to be calculated. RESULTS: The DA approach caused substantially greater damage to the gluteus minimus muscle and tendon when compared with the DS approach (t-test, p = 0.049 and 0.003, respectively). The tensor fascia lata and rectus femoris muscles were damaged only in the DA approach. There was no difference in the amount of damage to the gluteus medius muscle and tendon, piriformis tendon, obturator internus tendon, obturator externus tendon or quadratus femoris muscle between approaches. The posterior soft-tissue releases of the DA approach damaged the gluteus minimus muscle and tendon, piriformis tendon and obturator internus tendon. CONCLUSION: The DS approach caused less soft-tissue damage than the DA approach. However the clinical relevance is unknown. Further clinical outcome studies, radiographic evaluation of component position, gait analyses and serum biomarker levels are necessary to evaluate and corroborate the safety and efficacy of the DS approach. Cite this article: Bone Joint J 2016;98-B1036-42.

Microbeam irradiation of the C. elegans nematode.

The understanding of complex radiation responses in biological systems, such as non-targeted effects as represented by the bystander response, can be enhanced by the use of genetically amenable model organisms. Almost all bystander studies to date have been carried out by using conventional single-cell in vitro systems, which are useful tools to characterize basic cellular and molecular responses. A few studies have been reported in monolayer explants and bystander responses have been also investigated in a three-dimensional normal human tissue system. However, despite the well-know usefulness of in vitro models, they cannot capture the complexity of radiation responses of living systems such as animal models. To carry out in vivo studies on the bystander effect we have developed a new technique to expose living organisms using proton microbeams. We report the use of a nematode C. elegans strain with a Green Fluorescent Protein (GFP) reporter for the hsp-4 heat-shock gene as an in vivo model for radiation studies. Exposing animals to heat and chemicals stressors leads to whole body increases in the hsp-4 protein reflected by enhanced fluorescence. We report here that gamma-rays also can induce stress response in a dose dependent manner. However, whole body exposure to stress agents does not allow for evaluation of distance dependent response in non targeted tissues: the so-called bystander effect. We used the RARAF microbeam to site specifically deliver 3 MeV protons to a site in the tail of young worms. GFP expression was enhanced after 24 hours in a number dependent manner at distances > 100 microm from the site of irradiation.

Early outcome of total hip arthroplasty using the direct lateral vs the posterior surgical approach.

A consecutive series of 49 patients who had a primary total hip arthroplasty (THA) for osteoarthritis is reviewed to determine the difference in clinical outcome between the direct lateral and the posterior surgical approaches to the hip. Group 1 comprised 28 patients off had THA by the same surgeon using a posterolateral approach. Group 2 comprised 21 patients who had THA using the direct lateral approach, modified from Hardinge. The improvement in the limp, abductor strength, Trendelenburg test, and range of motion over time was similar in the two groups. The average Harris hip score at 1 year was 90 for Group 1 (posterior approach) and Group 2 (lateral approach). At 2-year minimum follow up, the Harris hip score was 94 for both groups. Radiographic review showed that the incidence and severity of heterotopic bone was also similar for both groups. The authors conclude that the clinical and radiographic outcome for THA using the posterior and the lateral approaches to the hip yield similar clinical results.

Tibial intramedullary alignment in total knee arthroplasty.

This article describes a study that assessed the accuracy of a tibial intramedullary alignment device in 44 adult cadaveric tibiae. The results suggest that greater accuracy is achieved if the device is inserted fully to the level of the distal epiphyseal scar and if used in the nonvalgus tibia. When seating of the tibial guide rod is incomplete or when the tibia has a valgus anatomic bow, cross-checking with extramedullary alignment devices is recommended to maximize accuracy of tibial component position.

Ejection of the proximal scaphoid in a trans-scaphoid perilunate fracture dislocation. A case report.

Trans-scaphoid perilunate fracture dislocations are difficult injuries to treat. Described herein is the unusual case of a trans-scaphoid perilunate fracture dislocation in which the proximal scaphoid fragment was ejected into the volar aspect of the distal forearm. The significant displacement of the proximal fragment represented complete devascularization of this piece. This unique fracture raised difficult management issues in the treatment of this injury. A primary proximal row carpectomy was performed, with a successful clinical result.

Surgical arthrodesis of the neuropathic foot. A salvage procedure.

Reconstructive foot and ankle surgery is a salvage procedure in the deformed neuropathic foot, despite condemnation by some authors. Clinical union and stability was achieved in 91% of the patients, and soft-tissue coverage without skin breakdown was achieved in 100% of the cases. Although one patient had moderate to severe pain in her ankle after operation and was able to do only bed-to-wheelchair transfers, she had good clinical stability, no skin ulceration, and was satisfied overall with the procedure. In addition, a significant component of her pain was believed to be from diabetic neuropathy and not pain that was directly attributable to her reconstructive surgery. All other patients were able to ambulate to some degree. More than half had unlimited use of the affected lower extremity. More than half of the patients had mild or no pain, and all patients had a functional limb. Surgical arthrodesis of the deformed neuropathic foot as a salvage procedure can preserve the limb as a stable functional unit, and create an acceptable alignment of the ankle-foot complex that will promote viability of the overlying soft-tissue structures.

An anatomical study of the tarsal tunnel using low pressure compartmental infusion.

The anatomy of the tarsal tunnel is demonstrated using a low-pressure compartmental infusion technique. This is done by infusing colored radiopaque contrast material into three fresh cadaveric specimens. Thin section photography and computed tomography are then used to identify the boundaries and contents of the tarsal tunnel as it traverses the ankle, hindfoot, and midfoot. The tarsal tunnel is shown to communicate proximally with the deep posterior compartment of the leg and distally with the intermediate compartment of the forefoot. The relationships of the structures contained within the tarsal tunnel are shown in detail.

Difficult reductions in traumatic patellar dislocation.

A traumatic lateral dislocation with internal rotation of the patella can be unreducible using conventional maneuvers. These unusual dislocations may involve locking of the patella on the lateral femoral condyle. In these cases, reduction can be achieved by applying a downward force to the lateral aspect of the patella, which reduces the rotational deformity and unlocks the medial patellar facet.

Compartment pressures of the leg following intramedullary fixation of the tibia.

A prospective study was performed to determine whether compartment pressures of the leg were affected by intramedullary fixation of the tibia. Ten of the 11 patients studied had surgery for acute diaphyseal fractures and 1 for tibial nonunion. Compartment pressures were measured immediately prior to the procedure and at 12 hours after the procedure. There was no difference between the preoperative and postoperative compartment pressures. Our data suggest that intramedullary stabilization of the tibia does not predictably increase compartment pressures.

Pedicle screw instrumentation for thoracolumbar burst fractures and fracture-dislocations.

Thirty-eight patients with unstable thoracolumbar and lumbar (T12-L5) spine fractures were treated with Cotrel-Dubousset pedicle screw instrumentation. They were followed for an average of 22.73 months (range 12-39). Measurements of canal compromise, wedge index, and kyphosis correction at follow-up examination were made. Thirty-three (86%) patients responded to a questionnaire concerning overall satisfaction, use of pain medication and return to work. There was an overall correction of kyphosis at follow-up of only one degree after a loss of six degrees from operative correction. There were nine cases of bent or broken screws that occurred at the thoracolumbar junction. Only one patient with instrumentation required continued pain medication and most had returned to work. Thirty-two of thirty-three patients were satisfied with the overall surgical result and twenty-eight of thirty-three patients had returned to work.